Energy Conservation Program: Test Procedure for Distribution Transformers, 51230-51255 [2021-19366]
Download as PDF
<![CDATA[
51230
Federal Register / Vol. 86, No. 175 / Tuesday, September 14, 2021 / Rules and Regulations
[EERE–2017–BT–TP–0055]
Washington, DC 20585–0121.
Telephone: (202) 586–2555. Email:
matthew.ring@hq.doe.gov.
SUPPLEMENTARY INFORMATION:
RIN 1904–AE19
Table of Contents
DEPARTMENT OF ENERGY
10 CFR Part 431
Energy Conservation Program: Test
Procedure for Distribution
Transformers
Office of Energy Efficiency and
Renewable Energy, Department of
Energy.
ACTION: Final rule.
AGENCY:
The U.S. Department of
Energy (‘‘DOE’’) is amending the test
procedure for distribution transformers
to revise and add definitions of certain
terms, update provisions based on the
latest versions of relevant industry
testing standards, and to specify the
basis for voluntary representations at
additional per-unit loads and additional
reference temperatures. The updates in
this final rule will not significantly
change the test procedure.
DATES: The effective date of this rule is
October 14, 2021. The final rule changes
will be mandatory for product testing
starting March 14, 2022.
ADDRESSES: The docket, which includes
Federal Register notices, comments,
and other supporting documents/
materials, is available for review at
www.regulations.gov. All documents in
the docket are listed in the
www.regulations.gov index. However,
some documents listed in the index,
such as those containing information
that is exempt from public disclosure,
may not be publicly available.
A link to the docket web page can be
found at www.regulations.gov/docket/
EERE-2017-BT-TP-0055. The docket
web page contains instructions on how
to access all documents, including
public comments, in the docket.
For further information on how to
review the docket contact the Appliance
and Equipment Standards Program staff
at (202) 287–1445 or by email:
ApplianceStandardsQuestions@
ee.doe.gov.
SUMMARY:
tkelley on DSK125TN23PROD with RULES2
FOR FURTHER INFORMATION CONTACT:
Mr. Jeremy Dommu, U.S. Department
of Energy, Office of Energy Efficiency
and Renewable Energy, Building
Technologies Office, EE–2J, 1000
Independence Avenue SW, Washington,
DC 20585–0121. Telephone: (202) 586–
9870. Email:
ApplianceStandardsQuestions@
ee.doe.gov.
Mr. Matthew Ring, U.S. Department of
Energy, Office of the General Counsel,
GC–33, 1000 Independence Avenue SW,
VerDate Sep<11>2014
20:08 Sep 13, 2021
Jkt 253001
I. Authority and Background
A. Authority
B. Background
II. Synopsis of the Final Rule
III. Discussion
A. Scope of Applicability
B. Updates to Industry Testing Standards
1. Recission of NEMA TP 2
2. Updates to IEEE Standards
C. Definitions
1. Rectifier Transformers and Drive
Transformers
2. New Definitions
3. Updated Definitions
D. Per-Unit Load Testing Requirements
1. Multiple-PUL Weighted-Average
Efficiency Metric
2. Single-PUL Efficiency Metric
3. Voluntary Representations of Efficiency
at Additional PULs
E. Multiple Voltage Capability
F. Other Test Procedure Topics
1. Per-Unit Load Specification
2. Reference Temperature Specification
3. Measurement Location
4. Specification for Stabilization of Current
and Voltage
5. Ambient Temperature Tolerances
6. Harmonic Current
7. Other Editorial Revisions
G. Effective and Compliance Dates
H. Test Procedure Costs
IV. Procedural Issues and Regulatory Review
A. Review Under Executive Order 12866
B. Review Under the Regulatory Flexibility
Act
C. Review Under the Paperwork Reduction
Act of 1995
D. Review Under the National
Environmental Policy Act of 1969
E. Review Under Executive Order 13132
F. Review Under Executive Order 12988
G. Review Under the Unfunded Mandates
Reform Act of 1995
H. Review Under the Treasury and General
Government Appropriations Act, 1999
I. Review Under Executive Order 12630
J. Review Under Treasury and General
Government Appropriations Act, 2001
K. Review Under Executive Order 13211
L. Review Under Section 32 of the Federal
Energy Administration Act of 1974
M. Congressional Notification
V. Approval of the Office of the Secretary
I. Authority and Background
DOE is authorized to establish and
amend energy conservation standards
and test procedures for certain
industrial equipment, including
distribution transformers. The current
DOE test procedure for distribution
transformers appear at title 10 of the
Code of Federal Regulations (‘‘CFR’’)
431.193 and appendix A to subpart K of
10 CFR part 431 (‘‘appendix A’’)
respectively. The current energy
conservation standards for distribution
PO 00000
Frm 00002
Fmt 4701
Sfmt 4700
transformers appear at 10 CFR 431.196.
The following sections discuss DOE’s
authority to establish test procedures for
distribution transformers and relevant
background information regarding
DOE’s consideration of test procedures
for this equipment.
A. Authority
The Energy Policy and Conservation
Act, as amended (‘‘EPCA’’),1 authorizes
DOE to regulate the energy efficiency of
a number of consumer products and
certain industrial equipment. (42 U.S.C.
6291–6317, as codified) Title III, Part B 2
of EPCA established the Energy
Conservation Program for Consumer
Products Other Than Automobiles (42
U.S.C. 6291–6309, as codified), which
sets forth a variety of provisions
designed to improve energy efficiency of
specified consumer products. Title III,
Part C 3 of EPCA, added by the National
Energy Conservation Policy Act, Public
Law 95–619, Title IV, section 441(a),
established the Energy Conservation
Program for Certain Industrial
Equipment (42 U.S.C. 6311–6317, as
codified), which sets forth a variety of
provisions designed to improve energy
efficiency of certain industrial
equipment. This equipment includes
distribution transformers, the subject of
this final rule. (42 U.S.C. 6317(a))
The energy conservation program
under EPCA consists essentially of four
parts: (1) Testing, (2) labeling, (3)
Federal energy conservation standards,
and (4) certification and enforcement
procedures. Relevant provisions of
EPCA for distribution transformers
specifically include definitions (42
U.S.C. 6291; 42 U.S.C. 6311), test
procedures (42 U.S.C. 6293; 42 U.S.C.
6317), labeling provisions (42 U.S.C.
6294; 42 U.S.C. 6315), energy
conservation standards (42 U.S.C. 6295;
42 U.S.C. 6317), and the authority to
require information and reports from
manufacturers (42 U.S.C. 6296; 42
U.S.C. 6316).
The Federal testing requirements
consist of test procedures that
manufacturers of covered products and
covered equipment must use as the
basis for: (1) Certifying to DOE that their
products or equipment comply with the
applicable energy conservation
standards adopted pursuant to EPCA (42
U.S.C. 6295(s); 42 U.S.C. 6316(a)), and
(2) making representations about the
efficiency of those covered products or
1 All references to EPCA in this document refer
to the statute as amended through the Energy Act
of 2020, Public Law 116–260 (Dec. 27, 2020).
2 For editorial reasons, upon codification in the
U.S. Code, Part B was redesignated Part A.
3 For editorial reasons, upon codification in the
U.S. Code, Part C was redesignated Part A–1.
E:\FR\FM\14SER2.SGM
14SER2
Federal Register / Vol. 86, No. 175 / Tuesday, September 14, 2021 / Rules and Regulations
covered equipment (42 U.S.C. 6293(c);
42 U.S.C. 6314(d)). Similarly, DOE must
use these test procedures to determine
whether the products or equipment
comply with relevant standards
promulgated under EPCA. (42 U.S.C.
6295(s); 42 U.S.C. 6316(a))
Federal energy efficiency
requirements for covered products and
covered equipment established under
EPCA generally supersede State laws
and regulations concerning energy
conservation testing, labeling, and
standards. (42 U.S.C. 6297; 42 U.S.C.
6316(a) and (b)) DOE may, however,
grant waivers of Federal preemption for
particular State laws or regulations, in
accordance with the procedures and
other provisions of EPCA. (42 U.S.C.
6297(d); 42 U.S.C. 6316(b)(2)(D))
EPCA set forth the criteria and
procedures DOE must follow when
prescribing or amending test procedures
for covered products 4 and covered
equipment, respectively. EPCA requires
that any test procedures prescribed or
amended under these sections be
reasonably designed to produce test
results which measure energy
efficiency, energy use or estimated
annual operating cost of a covered
product during a representative average
use cycle or period of use and not be
unduly burdensome to conduct. (42
U.S.C. 6293(b)(3); see also 42 U.S.C.
6314(a)(2))
EPCA also requires that, at least once
every 7 years, DOE evaluate test
procedures for each type of covered
product and covered equipment,
including distribution transformers, to
determine whether amended test
procedures would more accurately or
fully comply with the requirements for
the test procedures to not be unduly
burdensome to conduct and be
reasonably designed to produce test
results that reflect energy efficiency,
energy use, and estimated operating
costs during a representative average
use cycle. (42 U.S.C. 6293(b)(1)(A); see
also 42 U.S.C. 6314(a)(1))
If the Secretary determines, on her
own behalf or in response to a petition
by any interested person, that a test
procedure should be prescribed or
amended, the Secretary shall promptly
publish in the Federal Register
proposed test procedures and afford
interested persons an opportunity to
present oral and written data, views,
and arguments with respect to such
procedures. The comment period on a
proposed rule to amend a test procedure
shall be at least 60 days and may not
exceed 270 days. In prescribing or
amending a test procedure, the
Secretary shall take into account such
information as the Secretary determines
relevant to such procedure, including
technological developments relating to
energy use or energy efficiency of the
type (or class) of covered products or
covered equipment involved. (42 U.S.C.
6293(b)(2)) If DOE determines that test
procedure revisions are not appropriate,
DOE must publish its determination not
to amend the test procedures. DOE is
publishing this final rule in satisfaction
of the 7-year review requirement
specified in EPCA. (42 U.S.C.
6293(b)(1)(A); see also 42 U.S.C.
6314(b)(1))
DOE is issuing this final rule to
amend the test procedure for
distribution transformers in accordance
with its statutory obligations.
B. Background
With respect to distribution
transformers, EPCA states that the test
procedures for distribution transformers
shall be based on the ‘‘Standard Test
Method for Measuring the Energy
Consumption of Distribution
Transformers’’ prescribed by the
National Electrical Manufacturers
Association (NEMA TP 2–1998). (42
U.S.C. 6293(b)(10)(A)) Further, DOE
51231
may review and revise the DOE test
procedure. (42 U.S.C. 6293(b)(10)(B))
Consistent with the requirements in
EPCA, DOE published a final rule on
April 27, 2006, that established the test
procedure for distribution transformers
based on the test methods in NEMA TP
2–1998 and the test methods contained
in the Institute of Electrical and
Electronics Engineers (‘‘IEEE’’)
Standards C57.12.90–1999 and
C57.12.91–2001. 71 FR 24972, 24974.
See 71 FR 24972 (April 27, 2006)
(‘‘April 2006 Final Rule’’).5
In a final rule published on April 18,
2013, amending the energy conservation
energy conservation standards (‘‘ECS’’)
for distribution transformers (‘‘April
2013 ECS Final Rule’’), DOE determined
that the test procedure did not require
amendment at that time, concluding
that the test procedure as established in
the April 2006 Final Rule was
reasonably designed to produce test
results that reflect energy efficiency and
energy use, as required by 42 U.S.C.
6314(a)(2). 78 FR 23336, 23347–23348.
The current test procedures for
distribution transformers may be found
in 10 CFR 431.193 and 10 CFR part 431,
subpart K, appendix A.
On September 22, 2017, DOE
published a request for information
(‘‘RFI’’) to collect data and information
to inform its consideration of whether to
amend DOE’s test procedure for
distribution transformers (‘‘September
2017 RFI’’). 82 FR 44347. After
consideration of comments received in
response to the September 2017 RFI,
DOE published a notice of proposed
rulemaking (‘‘NOPR’’) on May 10, 2019
(‘‘May 2019 NOPR’’), presenting DOE’s
proposals to amend the distribution
transformer test procedure. 84 FR
20704.
DOE received comments in response
to the May 2019 NOPR from the
interested parties listed in Table I.1.
tkelley on DSK125TN23PROD with RULES2
TABLE I.1—WRITTEN COMMENTS RECEIVED IN RESPONSE TO MAY 2019 NOPR
Organization(s) *
Reference in
this document
Appliance Standards Awareness Project, American Council for an Energy-Efficient
Economy, Natural Resources Defense Council.
Cargill ...........................................................................................................................
Copper Development Association ...............................................................................
Howard Industries Inc ..................................................................................................
HVOLT Inc ...................................................................................................................
National Electrical Manufacturers Association ............................................................
Pacific Gas & Electric Company .................................................................................
Efficiency Advocates
Efficiency Organizations.
Cargill ......................
CDA ........................
Howard ....................
HVOLT ....................
NEMA ......................
PG&E ......................
Insulating Liquid Manufacturer.
Trade Association.
Manufacturer.
Industry Consultant.
Trade Association.
Electrical Utility.
Organization type
* This list includes only those commenters that provided comments relevant to the May 2019 NOPR.
4 DOE generally refers to distribution transformers
as covered equipment. However, to the extent that
DOE is discussing provisions of Part B of EPCA that
VerDate Sep<11>2014
20:08 Sep 13, 2021
Jkt 253001
are applicable to distribution transformers,
‘‘covered product’’ is used.
PO 00000
Frm 00003
Fmt 4701
Sfmt 4700
5 DOE published a technical correction to the
April 2006 Final Rule to correct typographical
errors. 71 FR 60662 (Oct. 16, 2006).
E:\FR\FM\14SER2.SGM
14SER2
51232
Federal Register / Vol. 86, No. 175 / Tuesday, September 14, 2021 / Rules and Regulations
A parenthetical reference at the end of
a comment quotation or paraphrase
provides the location of the item in the
public record.6
II. Synopsis of the Final Rule
In this final rule, DOE amends 10 CFR
431.192, 431.193, 431.196, and
appendix A as follows:
(1) Explicitly specify that the test
procedure is applicable only to
distribution transformers that are
subject to energy conservation
standards,
(2) Include new definitions for ‘‘perunit load,’’ ‘‘terminal’’ and ‘‘auxiliary
device,’’ and updated definitions for
‘‘low-voltage dry-type distribution
transformer’’ and ‘‘reference
temperature,’’
(3) Reflect certain revisions from the
latest version of the IEEE testing
standards on which the DOE test
procedure is based,
(4) Incorporate other clarifying
revisions based on review of the DOE
test procedure,
(5) Specify use of existing test
procedure provisions for voluntary
(optional) representations at additional
per-unit loads (‘‘PULs’’) and reference
temperatures, and
(6) Centralize the PUL and reference
temperature specifications for
certification to energy conservation
standards and for voluntary
representations.
The adopted amendments are
summarized in Table II.1 compared to
the test procedure provision prior to the
amendment, as well as the reason for
the adopted change. Table II.2 compares
the changes adopted in this final rule to
the proposal of the May 2019 NOPR.
TABLE II.1—SUMMARY OF CHANGES IN THE AMENDED TEST PROCEDURE
DOE test procedure
prior to amendment
Amended test procedure
(adopted by this final rule)
Current test procedure does not specify scope
tkelley on DSK125TN23PROD with RULES2
PUL is referred to as ‘‘percent load,’’ ‘‘percent
of nameplate-rated load,’’ ‘‘percent of the
rated load,’’ or ‘‘per unit load level’’.
Does not define ‘‘Per-unit load,’’ ‘‘Terminal’’ and
‘‘Auxiliary device,’’ which are used in the current test procedure (TP).
Includes definition of ‘‘Low-Voltage Dry-Type
Distribution Transformer’’.
Test procedure provisions are based on four
IEEE testing standards, which contain general requirements and methods for performing tests:
C57.12.00–2000.
C57.12.01–1998.
C57.12.90–1999.
C57.12.91–2001.
Requires reporting performance at the rated
frequency; however, the rated frequency is
not explicitly defined.
Requires determining winding resistance but
does not specify whether the polarity of the
core magnetization should be kept constant
as measurements are made.
Requires the measurement of load and no-load
loss, without explicitly specifying the connection locations for measurements.
Testing with a sinusoidal waveform explicitly
specified only for transformers designed for
harmonic currents.
Energy conservation standards require that efficiency be determined at a single PUL of 50
percent for both liquid-immersed and medium-voltage dry type (MVDT) distribution
transformers, and at 35 percent for low-voltage dry-type (LVDT) distribution transformers.
Specifies PUL and reference temperature specifications for certification to energy conservation standards in multiple locations throughout appendix A.
6 The parenthetical reference provides a reference
for information located in the docket of DOE’s
rulemaking to develop test procedures for
VerDate Sep<11>2014
20:08 Sep 13, 2021
Jkt 253001
Attribution
States explicitly that the scope of the test procedure is limited to the scope of equipment
subject to the energy conservation standards.
Consolidates all terms to only ‘‘per-unit load’’
Clarification added by DOE.
Adds new definitions for ‘‘Per-unit load,’’
‘‘Terminal,’’ and ‘‘Auxiliary device’’.
Reflects industry testing standard definition
(terminal) and clarification added by DOE
(PUL and auxiliary device).
Aligns with industry definition.
Updates definition of ‘‘Low-Voltage Dry-Type
Distribution Transformer’’.
Updates provisions based on the latest
version of the four IEEE testing standards:
C57.12.00–2015. ......................................
C57.12.01–2020. ......................................
C57.12.90–2015. ......................................
C57.12.91–2020. ......................................
Improves consistency and readability of test
procedure.
Reflects industry testing standard updates.
States explicitly that all testing under the DOE
test procedure is to occur only at 60 Hz.
Update to reflect industry testing standards.
Specifies that the polarity of the core magnetization be kept constant during all resistance readings.
Update to reflect industry testing standards.
Specifies explicitly that load and no-load loss
measurements are required to be taken
only at the transformer terminals.
Specifies that all transformers must be tested
using a sinusoidal waveform (not just those
designed for harmonic current).
Permits voluntary representations of efficiency, load loss and no-load loss at additional PULs and/or reference temperature,
using the DOE test procedure. (Does not
require certification to DOE of any voluntary
representations.)
Centralizes the PUL and reference temperature specifications, both for the certification
to energy conservation standards and for
use with a voluntary representation.
Update to reflect industry testing standards.
distribution transformers. (Docket No. EERE–2017–
BT–STD–0055, which is maintained at
www.regulations.gov). The references are arranged
PO 00000
Frm 00004
Fmt 4701
Sfmt 4700
Update to reflect industry practice.
Response to industry comment.
Improves readability of test procedure.
as follows: (commenter name, comment docket ID
number, page of that document).
E:\FR\FM\14SER2.SGM
14SER2
Federal Register / Vol. 86, No. 175 / Tuesday, September 14, 2021 / Rules and Regulations
51233
TABLE II.2—SUMMARY OF CHANGES—FINAL RULE RELATIVE TO MAY 2019 NOPR
DOE test procedure
prior to amendment
NOPR proposal
Current test procedure does not specify scope
PUL is referred to as ‘‘percent load,’’ ‘‘percent
of nameplate-rated load,’’ ‘‘percent of the
rated load,’’ or ‘‘per unit load level’’.
Does not define ‘‘Per-unit load,’’ ‘‘Terminal’’ and
‘‘Auxiliary device,’’ which are used in the current TP.
Aligns definition of ‘‘Low-Voltage Dry-Type Distribution Transformer’’ with industry definition.
Test procedure provisions are based on four
IEEE testing standards, which contain general requirements and methods for performing tests:
C57.12.00–2000.
C57.12.01–1998.
C57.12.90–1999.
C57.12.91–2001.
Automatic Recording of Data Not Required .......
Requires reporting performance at the rated
frequency; however, the rated frequency is
not explicitly defined.
Requires determining winding resistance but
does not specify whether the polarity of the
core magnetization should be kept constant
as measurements are made.
Requires the measurement of load and no-load
loss, without explicitly specifying the connection locations for measurements.
Testing with a sinusoidal waveform explicitly
specified only for transformers designed for
harmonic currents.
Energy conservation standards require that efficiency be determined at a single PUL of 50
percent for both liquid-immersed and MVDT
distribution transformers, and at 35 percent
for LVDT distribution transformers.
tkelley on DSK125TN23PROD with RULES2
Specifies PUL and reference temperature specifications for certification to energy conservation standards in multiple locations throughout appendix A.
DOE has determined that the
amendments described in section III and
adopted in this document will not alter
the measured efficiency of distribution
transformers or require retesting or
recertification solely as a result of DOE’s
adoption of the amendments to the test
procedure. Additionally, DOE has
determined that the amendments will
not increase the cost of testing.
Discussion of DOE’s actions are
addressed in detail in section III of this
document.
The effective date for the amended
test procedure adopted in this final rule
is 30 days after publication of this
document in the Federal Register.
VerDate Sep<11>2014
22:37 Sep 13, 2021
Jkt 253001
Final rule
States explicitly that the scope of the test procedure is limited to the scope of equipment
subject to the energy conservation standards.
Consolidates all terms to only ‘‘per-unit load.’’
Adopts modification as proposed.
Adds new definitions for ‘‘Per-unit load,’’
‘‘Terminal,’’ and ‘‘Auxiliary device.’’.
Adopts modification as proposed.
Proposes updated definition of ‘‘Low-Voltage
Dry-Type Distribution Transformer.’’.
Updates provisions based on the latest
version of the four IEEE testing standards:
C57.12.00–2015.
C57.12.01–2015.
C57.12.90–2015.
C57.12.91–2011.
Slight change from NOPR to align with industry definition.
Adopts modifications as proposed. Note that
after NOPR publication, IEEE updated
C57.12.91–2011 and C57.12.01–2015 to
C57.12.91–2020 and C57.12.01–2020. The
relevant provisions of C57.12.91–2020 and
C57.12.01–2020 and the other two testing
standards are unchanged.
Requires automatic recording of data, as required in IEEE C57.12.90–2015 and IEEE
C57.12.91–2011, using a digital data acquisition system. (Appendix A, section
4.4.2(b)).
States explicitly that all testing under the DOE
test procedure is to occur only at 60 Hz for
resistance measurement and no-load loss
test.
Specifies that the polarity of the core magnetization be kept constant during all resistance readings.
NOPR proposal not adopted in this final rule.
Specifies explicitly that load and no-load loss
measurements are required to be taken
only at the transformer terminals.
Specifies that all transformers must be tested
using a sinusoidal waveform (not just those
designed for harmonic current).
Permits voluntary representations of efficiency, load loss and no-load loss at additional PULs and/or reference temperature,
using the DOE test procedure. (Does not
require certification to DOE of any voluntary
representations.)
Centralizes the PUL and reference temperature specifications, both for the certification
to energy conservation standards and for
use with a voluntary representation.
Adopts modification as proposed.
Representations of energy use or energy
efficiency must be based on testing in
accordance with the amended test
procedure beginning 180 days after the
publication of this final rule.
III. Discussion
A. Scope of Applicability
The applicability of the test procedure
is provided in 10 CFR 431.193, which
states that ‘‘the test procedures for
measuring the energy efficiency of
distribution transformers for purposes of
EPCA are specified in appendix A to
this subpart.’’ DOE has established
energy conservation standards for lowvoltage dry-type (‘‘LVDT’’) distribution
PO 00000
Frm 00005
Fmt 4701
Sfmt 4700
Adopts modification as proposed.
Adopted no-load loss test as proposed.
NOPR proposal not adopted for resistance
measurements.
Adopts modification as proposed.
Adopts modification as proposed.
Adopts modification as proposed.
No change from NOPR.
transformers, liquid-immersed
distribution transformers, and mediumvoltage dry type (‘‘MVDT’’) distribution
transformers at 10 CFR 431.196. In the
May 2019 NOPR, DOE proposed to state
explicitly that the scope of the test
procedure is limited to the scope of the
distribution transformers that are
subject to energy conservation
standards. 84 FR 20704, 20706. DOE did
not receive any comments regarding this
proposal. DOE is modifying text in 10
CFR 431.193 regarding the scope of the
test procedure as proposed.
E:\FR\FM\14SER2.SGM
14SER2
51234
Federal Register / Vol. 86, No. 175 / Tuesday, September 14, 2021 / Rules and Regulations
B. Updates to Industry Testing
Standards
The current DOE test procedure for
distribution transformers is based on
provisions from the following industry
testing standards (See 71 FR 24972,
24982 (April 27, 2006)):
• NEMA TP 2–1998, ‘‘Standard Test
Method for Measuring the Energy
Consumption of Distribution
Transformers’’ (NEMA TP 2–1998)
• IEEE C57.12.90–1999, ‘‘IEEE Standard
Test Code for Liquid-Immersed
Distribution, Power and Regulating
Transformers and IEEE Guide for
Short Circuit Testing of Distribution
and Power Transformers’’
• IEEE C57.12.91–2001, ‘‘IEEE Standard
Test Code for Dry-Type Distribution
and Power Transformers’’
• IEEE C57.12.00–2000, ‘‘IEEE Standard
General Requirements for LiquidImmersed Distribution, Power and
Regulating Transformers’’
• IEEE C57.12.01–1998, ‘‘IEEE Standard
General Requirements for Dry-Type
Distribution and Power Transformers
Including those with Solid Cast and/
or Resin Encapsulated Windings’’
In addition, the DOE test procedure is
also based on provisions in NEMA TP
2–2005,7 which in turn reference the
aforementioned IEEE testing standards.8
DOE determined that basing the
procedure on multiple industry testing
standards, as opposed to adopting an
industry test procedure (or procedures)
without modification, was necessary to
provide the detail and accuracy required
for the Federal test procedure, with the
additional benefit of providing
manufacturers the Federal test
tkelley on DSK125TN23PROD with RULES2
7 Standard Test Method for Measuring the Energy
Consumption of Distribution Transformers,
available at: nema.org/Standards/Pages/StandardTest-Method-for-Measuring-the-EnergyConsumption-of-Distribution-Transformers.aspx.
8 Prior to the April 2006 Final Rule, NEMA
provided the Department with its revised test
procedure document (i.e., update to NEMA TP 2–
1998), TP 2–2005. The Department treated this
submission as a comment on DOE’s rulemaking to
establish a distribution transformer test procedure.
71 FR 24972, 24973. As such, the DOE test
procedure incorporated a number of the changes
that this revision made to the rule language and
addressed the differences between the DOE test
procedure and NEMA TP 2–2005. Id.
VerDate Sep<11>2014
20:08 Sep 13, 2021
Jkt 253001
procedure in a single reference. 71 FR
24972, 24982 (April 27, 2006).
DOE previously sought comment on
the benefits and burdens of adopting
industry testing standards without
modification. 82 FR 44347, 44351 (Sep.
22, 2017). NEMA commented generally
that there is benefit but that DOE should
limit the reference to the measurement
of losses and retain DOE’s existing
calculation for efficiency. (NEMA,
Docket No. EERE–2017–BT–TP–0055–
0014 p. 9) DOE stated in the May 2019
NOPR that the current test procedure is
already based on industry testing
standards and that if DOE were to adopt
an industry testing standard without
modification, the resulting changes
could require manufacturers to retest
and recertify, because such an
incorporation by reference would
require updating a majority of the
current test procedure. 84 FR 20704,
20710. For these reasons, DOE did not
propose to incorporate industry testing
standard into its test procedure for
distribution transformers. Id.
NEMA further commented that while
the existing test procedure is adequate,
for high volume units the test
procedures found in IEEE C57.12.90–
2015 and IEEE C.57.12.91–2011 are less
burdensome and recommended that
DOE allow them as equivalent
alternatives for the purposes of testing
and certification. (NEMA, No. 30 at p.
5) As discussed, DOE’s test procedure is
partially based on the IEEE testing
standards, and there are similarities
between the DOE test procedure and the
IEEE testing standards. There are also
minor differences between the DOE test
procedure and the IEEE testing
standards, such as DOE’s requirement to
test multiple-voltage-capable
distribution transformers in the highest
losses configuration (appendix A,
sections 4.5.1(b) and 5.0), as discussed
in section III.E. Testing according to the
IEEE test procedures without
modification could result in distribution
transformers being tested at different
conditions depending on the method
used. Therefore, DOE is not permitting
use of IEEE testing standards as
equivalent alternatives. DOE may
consider referencing sections of the
IEEE test procedures as equivalent in
PO 00000
Frm 00006
Fmt 4701
Sfmt 4700
the future if there is sufficient data and
information that doing so would result
in equivalent measured efficiency
values with the DOE test procedure.
1. Recission of NEMA TP 2
As discussed, EPCA requires that DOE
base the test procedure on NEMA TP 2–
1998. (42 U.S.C. 6293(b)(10)(A)) Also as
discussed, the DOE test procedure is
based on (but does not incorporate by
reference directly) NEMA TP 2–1998,
NEMA TP 2–2005, as well as four IEEE
standards that are referenced in NEMA
TP 2–2005, i.e., IEEE.C57.12.00, IEEE
C57.12.01, IEEE C57.12.90 and IEEE
C57.12.91. See 71 FR 24972, 24982
(April 27, 2006). As discussed in the
following section, updates have been
made to the IEEE testing standards.
Since publication of the April 2006
Final Rule, NEMA TP 2–2005 has been
rescinded and superseded in industry
by the IEEE standards. DOE has
evaluated the provisions in the Federal
test procedure that are based on NEMA
TP 2 and, as discussed in the May 2019
NOPR, has determined that these
provisions remain appropriate for
testing distribution transformers. DOE
did not receive any comments on these
provisions in the May 2019 NOPR and
therefore maintained them in this final
rule.
2. Updates to IEEE Standards
a. Background
As discussed in section III.B, the DOE
test procedure mirrors four widely used
IEEE testing standards. Since the April
2006 Final Rule, all of the four IEEE
standards have been updated.
In the May 2019 NOPR, DOE
proposed updating certain Federal test
procedure provisions to reflect the
following updated versions of the
relevant IEEE testing standards: IEEE
C57.12.90–2015, IEEE C57.12.91–2011,
IEEE C57.12.00–2015, and IEEE
C57.12.01–2015. Since publication of
the May 2019 NOPR, IEEE issued a
further update to standard IEEE
C57.12.91 (IEEE C57.12.91–2020) and
IEEE C57.12.01–2015 (IEEE C57.12.01–
2020). Table III.1 provides a list of old
and new versions of each of these IEEE
testing standards.
E:\FR\FM\14SER2.SGM
14SER2
Federal Register / Vol. 86, No. 175 / Tuesday, September 14, 2021 / Rules and Regulations
51235
TABLE III.1—IEEE INDUSTRY TESTING STANDARDS VERSIONS AND SUMMARY
tkelley on DSK125TN23PROD with RULES2
IEEE standard
Version on which
DOE test
procedure prior
to amendment
is based
(year)
Most recent
IEEE revision
version
(year)
Content
C57.12.00 .........
2000
2015
C57.12.01 .........
C57.12.90 .........
1998
1999
2020
2015
C57.12.91 .........
2001
2020
b. General Updates
For the May 2019 NOPR, DOE
reviewed the then most current editions
of the relevant IEEE testing standards to
determine whether any of the updates
from the previously considered versions
warranted proposed amendments to the
DOE test procedure. The four IEEE
testing standards are not relevant to the
DOE test procedure in their entirety, as
they include specifications and test
methods beyond those required to
measure efficiency, such as test methods
for polarity, phase-relation, dielectric,
and audible sound-level. DOE
performed the review as follows:
(1) DOE identified the sections of the
IEEE testing standards that form the
basis of the DOE test procedure,
(2) DOE compared those sections
between the old and the then current
versions of the IEEE testing standards,
and
(3) DOE initially determined which of
the changes were editorial versus which
represented potential substantive
improvements to the test method.
In IEEE C57.12.90–2015 and IEEE
C57.12.91–2011, sections 5, 8, and 9
provide the resistance measurements,
the no-load loss test, and the load loss
test, respectively, which provide the
basis for the DOE test procedure. In
general, DOE did not identify major
changes in sections 5, 8, and 9 between
1999 and 2015 editions of IEEE
C57.12.90–2015, or between the 2001
and 2011 editions of IEEE C57.12.91–
2011. Since the May 2019 NOPR, DOE
has reviewed the updated IEEE
C57.12.91–2020 test procedure and
concluded that there were no
substantive differences between the
relevant provisions in the 2011 and
2020 versions.
The IEEE C57.12.00 and IEEE
C57.12.01 testing standards include
general electrical and mechanical
requirements for the test methods for
liquid-immersed and dry-type
distribution transformers, in IEEE
C57.12.90 and IEEE C57.12.91,
VerDate Sep<11>2014
20:08 Sep 13, 2021
Jkt 253001
General electrical and mechanical requirements for liquid-immersed distribution transformers.
General electrical and mechanical requirements for dry-type distribution transformers.
Methods for performing tests specified in C57.12.00 and others for liquid-immersed distribution transformers.
Methods for performing tests specified in C57.12.01 and others for dry-type distribution
transformers.
respectively. In IEEE C57.12.00 and
IEEE C57.12.01, section 9 and section 5,
respectively, provide accuracy
requirements for conducting the
resistance measurements, the no-load
loss test, and the load loss test. The
primary change DOE identified in the
accuracy requirements between the
2000 and 1998 standards and the 2015
standards was a slight relaxation of the
temperature system accuracy
requirement, from ±1 °C in the older
versions to ±1.5 °C for liquid-immersed
distribution transformers and ±2 °C for
medium-voltage dry-type distribution
transformers and low-voltage dry-type
distribution transformers. Since the May
2019 NOPR, DOE has reviewed the
updated IEEE C57.12.91–2020 test
procedure and concluded that there
were no substantive differences between
the relevant provisions in the 2015 and
2020 versions.
In the May 2019 NOPR, DOE
proposed a series of updates based on
the then most recent updates to the
relevant IEEE testing standards. 84 FR
20704, 20711. DOE stated the proposed
updates reflect current industry
practice, and as such, would not change
current measured values. Id. DOE
further stated that providing additional
specificity consistent with the updates
would improve the repeatability of the
test procedure. Id. DOE requested
comment on the proposed changes to
reflect the updates to the relevant IEEE
testing standards. Id.
DOE received comments from
Howard, NEMA, CDA, and HVOLT
agreeing that the proposed updates are
already industry practice and would not
change any values or increase testing
costs for manufacturers. (Howard, No.
32 at p.1; NEMA, No. 20 at p. 3; CDA,
No. 29 at p. 2; HVOLT, No. 27 at p. 91)
Based on its review of the updates to
the relevant IEEE testing standards and
following consideration of the
comments, DOE is adopting the
proposed updates and clarifications,
with two exceptions, discussed below.
PO 00000
Frm 00007
Fmt 4701
Sfmt 4700
c. Automatic Recording of Data
In the May 2019 NOPR, DOE
proposed to require automatic recording
of data using a digital data acquisition
system at appendix A, section 4.4.2(b),
in an attempt to align with industry
standards. 84 FR 20704, 20711. NEMA
commented that the proposed
requirement to automatically record
data using a digital data acquisition
system is listed in IEEE C57.12.90–2015
and C57.12.91–2020 for making
resistance measurements by the
voltmeter-ammeter method, and not for
the no-load loss measurements as was
proposed in the May 2019 NOPR.
(NEMA, No. 30 at p. 3) NEMA
commented that requiring automatic
recording of data using a digital data
acquisition system for the no-load losses
could require some labs to upgrade test
equipment, as not all power analyzers
have this capability. Id.
DOE acknowledges that IEEE
C57.12.90–2015 and C57.12.91–2020
both cite using digital data acquisition
systems for making resistance
measurements by the voltmeterammeter method and not for no-load
losses, as was proposed. In an effort to
remain aligned with the industry testing
standard IEEE C57.12.90–2015 and
C57.12.91–2020 no-load loss test, DOE
has not adopted the proposal to require
automatic recording of data using a
digital data acquisition system. DOE is
maintaining the current specification in
section 4.4.2(b) of appendix A that
requires recording data ‘‘as close to
simultaneously as possible.’’
d. Test Frequency
In the May 2019 TP NOPR, DOE
proposed to require testing under the
DOE test procedure to occur only at 60
Hz in appendix A, sections 3.1(c) and
4.1, in order to align with the industry
testing standard and provide clarity on
the frequency of the test current. 84 FR
20704, 20711.
NEMA commented that there was an
error in the proposed language of
E:\FR\FM\14SER2.SGM
14SER2
51236
Federal Register / Vol. 86, No. 175 / Tuesday, September 14, 2021 / Rules and Regulations
section 3.1(c) of Appendix A, stating
that the proposed regulatory text should
read ‘‘Measure resistance with the
transformer energized by a DC supply’’
rather than with a 60 Hz supply as was
proposed in the May 2019 NOPR.
(NEMA, No. 30 at p. 5) DOE concurs
with NEMA that the 60 Hz supply
frequency is not applicable to the
resistance measurement section of the
test procedure, only to the loss
measurement sections. The proposed
addition of section 3.1(c) of appendix A,
was an error. Resistance measurements
are already stated as being a ‘‘direct
current resistance’’ measurement in
appendix A, section 3.1(b). Therefore,
DOE is not adopting section 3.1(c) of
appendix A as was proposed in the May
2019 NOPR.
The proposed language clarifying the
‘‘Test Frequency’’ provision in appendix
A, section 4.1, is aligned with the
industry standard to test at the ‘‘rated
frequency,’’ which by the definition of
distribution transformer at 10 CFR
431.192 is 60Hz. Therefore, this
proposed addition remains appropriate.
DOE did not receive any comment in
opposition to its proposal to clarify that
appendix A, section 4.1, is to be
conducted with a 60 Hz frequency
current. Therefore, DOE is adopting the
change as proposed to section 4.1.
e. Summary of Updates Adopted in This
Final Rule
rule. As summarized previously, DOE
received comments from industry trade
organizations and individual
manufacturers indicating that the
proposed updates are already industry
practice and would not change any
values or increase testing costs for
manufacturers. (Howard, No. 32 at p. 1;
NEMA, No. 30 at p. 3; CDA, No. 29 at
p. 2; HVOLT, No. 27 at p. 91) As such,
DOE has determined that the following
amendments reflect current industry
practice and provide additional
specificity that will improve the
repeatability of the test procedure.
Table III.2 summarizes proposed
updates to the relevant IEEE testing
standards that are adopted in this final
TABLE III.2—IEEE-BASED UPDATES ADOPTED IN THIS FINAL RULE
Topic
Updates based on IEEE standards
Consolidating the Terms ‘‘Oil,’’ ‘‘Transformer Liquid,’’ and ‘‘Insulating
Liquid’’.
Replace the term ‘‘oil’’ and ‘‘transformer liquid’’ with ‘‘insulating liquid’’
in Appendix A to reflect that the term is inclusive of all insulating liquids, including those identified in IEEE C57.12.90–2015.
Specify, consistent with IEEE C57.12.90–2015, that resistance measurements are considered stable if the top insulating liquid temperature does not vary more than 2 °C in a one-hour period. (Appendix
A, section 3.2.1.2(b))
Relax the temperature test system accuracy requirements to be within
±1.5 °C for liquid-immersed distribution transformers, and ±2.0 °C for
MVDT and LVDT distribution transformers, as specified in IEEE
C57.12.00–2015 and IEEE C57.12.01–2020, respectively. (Appendix
A, section 2.0)
Permit use of the voltmeter-ammeter method when the rated current of
the winding is less than or equal to 1 A. Neither IEEE C57.12.90–
2015 nor IEEE C57.12.91–2020 restrict usage of this method to certain current ranges. (Appendix A, section 3.3.2(a))
Include the requirement that a minimum of four readings for current
and voltage must be used for each resistance measurement, as
specified in IEEE C57.12.90–2015. (Appendix A, section 3.3.2(b))
Add resistance measurement specifications for single-phase windings,
wye windings and delta windings, as provided in section 5.4.1 and
5.4.2 of IEEE C57.12.90–2015, and sections 5.6.1 through 5.6.3 of
IEEE C57.12.91–2020. (Appendix A, section 3.4.1(g)–(i))
Require that all testing under the DOE test procedure is to occur only
at 60 Hz. (Appendix A, section 4.1)
Require that the polarity of the core magnetization be kept constant
during all resistance readings. (Appendix A, section 3.4.1(f))
Stability Requirement for Resistance Measurement ................................
Temperature Test System Accuracy ........................................................
Limits for Voltmeter-Ammeter Method .....................................................
Number of Readings Required for Resistance Measurement .................
Connection Locations for Resistance Measurements ..............................
Test Frequency .........................................................................................
Polarity of Core Magnetization .................................................................
C. Definitions
Definitions pertaining to distribution
transformers are provided at 10 CFR
431.192. The following sections discuss
new and amended definitions
established in this final rule.
tkelley on DSK125TN23PROD with RULES2
1. Rectifier Transformers and Drive
Transformers
DOE defines rectifier transformer as a
transformer that operates at the
fundamental frequency of an
alternating-current system and that is
designed to have one or more output
windings connected to a rectifier.9 10
CFR 431.192.
DOE defines drive (isolation)
transformer as a transformer that (1)
isolates an electric motor from the line;
(2) accommodates the added loads of
drive-created harmonics; and (3) is
designed to withstand the mechanical
stresses resulting from an alternating
current adjustable frequency motor
drive or a direct current motor drive. 10
CFR 431.192. The parenthetical
inclusion of the term ‘‘isolation’’
indicates that the defined term includes
9 A rectifier is an electrical device for converting
alternating current to direct current.
VerDate Sep<11>2014
20:08 Sep 13, 2021
Jkt 253001
PO 00000
Frm 00008
Fmt 4701
Sfmt 4700
only isolation transformers and not
other transformers that may be
described as ‘‘drive transformers’’ in the
industry but which do not satisfy all
three criteria specified in the definition
of drive (isolation) transformer.
Both rectifier transformers and drive
transformers are among the exclusions
to the term ‘‘distribution transformer’’ at
10 CFR 431.192 and 42 U.S.C.
6293(35)(B)(ii). Because both rectifier
transformers and drive transformers are
not classified as distribution
transformers, they are not subject to the
energy conservation standards at 10 CFR
431.196.
E:\FR\FM\14SER2.SGM
14SER2
tkelley on DSK125TN23PROD with RULES2
Federal Register / Vol. 86, No. 175 / Tuesday, September 14, 2021 / Rules and Regulations
Although rectifier transformers and
drive transformers are defined
differently, they typically share features.
As discussed in the May 2019 NOPR,
both are isolation transformers (i.e., not
autotransformers); both are typically
exposed to (and must tolerate)
significant harmonic content created
from the drive or power supply; and
both are likely to include design
features enabling them to bear
mechanical stress resulting from rapid
current changes that may arise from
operation of motors and other industrial
equipment. 84 FR 207054, 20708.
In response to the September 2017
RFI, Babanna Suresh (‘‘Suresh’’)
commented that it could be argued that
most distribution-type transformers
meet the present definition of the terms
‘‘rectifier transformer’’ or ‘‘drive
transformer’’ and suggested that those
terms be removed from the list of
exclusions to the term ‘‘distribution
transformer.’’ (Suresh, Docket No.
EERE–2017–BT–TP–0055, No. 9 at p. 1)
Suresh further suggested that the
definition of ‘‘rectifier transformer’’ be
limited to transformers that supply
loads that are composed of at least 75
percent power electronics. Id.
In the May 2019 NOPR, DOE stated
that the definition of ‘‘rectifier
transformer’’ is not intended to cover a
large number of transformers intended
for general power service; and that
linking the definition to a percentage of
supply load from power electronics
would be insufficient to designate a
distribution transformer because it may
not be possible for a manufacturer to
know in advance what fraction of a
distribution transformer’s load will
include power electronics. 84 FR
207054, 20708. Based on further review
of industry testing standards and
available manufacturer literature, DOE
further stated that it was unable to
identify physical attributes that could be
used to reliably identify rectifier
transformers. Id.
DOE requested comment on whether
the current definitions of rectifier
transformer and drive transformer are
sufficiently specific; the level of
technical similarity between the two
types of transformers; and whether any
physical or electrical properties could
be used to reliably identify rectifier
transformers.
DOE received written comments from
CDA and HVOLT stating that defining
rectifier transformers as having multiple
output windings could be a reasonable
addition. (CDA, No. 29 at p.1; HVOLT
No. 27 at p. 89) DOE notes that the
current definition already specifies that
rectifier transformers can have ‘‘one or
VerDate Sep<11>2014
20:08 Sep 13, 2021
Jkt 253001
more’’ output windings. 10 CFR
431.192.
CDA and HVOLT also stated that
small drive transformers could meet
energy conservations standards, but that
larger drive transformers are more
complicated and would have a more
difficult time meeting standards. (CDA,
No. 29 at p.1–2; HVOLT No. 27 at p. 89)
While smaller drive transformers may
be able to meet energy conservation
standards, the statutory definition for
distribution transformer excludes any
transformer that is designed to be used
in a special purpose applications and is
unlikely to be used in general purpose
applications, and specifies drive
transformers as such an example. 42
U.S.C. 6291(35)(b)(ii).
NEMA commented that the current
definition for both rectifier transformer
and drive transformer are sufficient.
(NEMA, No. 30 at p.2).
Having considered these comments
from interested parties, DOE remains
unaware of any industry definition or
physical features that would better
define either rectifier transformers or
drive transformers.
Therefore, DOE makes no changes to
the definitions of ‘‘rectifier transformer’’
and ‘‘drive transformer’’ in this final
rule. Both varieties of equipment remain
excluded from energy conservation
standards and are therefore excluded
from the scope of the test procedure (in
accordance with the amendment
discussed in section III.A of this final
rule specifying that the scope of the test
procedure is limited to the scope of the
distribution transformers that are
subject to energy conservation
standards). However, as stated in the
April 2006 Final Rule, DOE narrowly
construes the exclusions from the
definition of ‘‘distribution transformer.’’
DOE will also take appropriate steps,
including enforcement action if
necessary, if any manufacturer or other
party erroneously invokes one of the
exclusions as a basis for marketing a
transformer that is a ‘‘distribution
transformer,’’ but does not meet DOE
standards. Moreover, to the extent
transformers that do fall within the
exclusions begin to be marketed for
standard distribution applications, or
find widespread use in such
applications, DOE will examine whether
re-defining the relevant exclusions is
warranted. See 71 FR 24979.
2. New Definitions
In the May 2019 NOPR, DOE
proposed and sought comment on
definitions for the terms ‘‘per-unit
load,’’ ‘‘terminal,’’ and ‘‘auxiliary
device.’’ 84 FR 20704, 20708–20709.
These terms are referenced in the DOE
PO 00000
Frm 00009
Fmt 4701
Sfmt 4700
51237
test procedure but are not currently
defined in the regulatory text. The
following sections discuss comments
received regarding each of these terms
and the definitions established in this
final rule.
a. Per-Unit Load
Distribution transformers are regularly
operated at capacities other than the
capacity listed on a distribution
transformer’s nameplate (i.e., the rated
load). In general, distribution
transformers are loaded substantially
below their rated load. DOE’s current
test procedure and energy conservation
standards for distribution transformers
use various terms to refer to operating
or testing a distribution transformer at a
capacity other than the rated load,
including ‘‘percent load,’’ ‘‘percent of
nameplate-rated load,’’ ‘‘percent of the
rated load,’’ or ‘‘per unit load level.’’ 10
CFR 431.192, 10 CFR 431.196, and
appendix A. DOE proposed to
consolidate the usage of these various
terms into a single term, ‘‘per-unit load’’
(‘‘PUL’’) in all instances identified. 84
FR 20704, 20709. DOE also proposed to
define ‘‘per-unit load’’ to mean the
fraction of rated load. Id.
Howard, CDA, and HVOLT supported
the proposed term per-unit load.
(Howard, No. 32 at p.1; CDA, No. 29 at
p.2; HVOLT, No. 27 at p. 89) DOE did
not receive any comments against its
proposed definition for per-unit load or
its proposal to consolidate all references
to partial loading into a single per-unit
load term. In order to improve the
readability of the test procedure, DOE is
adopting the proposed definition for
per-unit load at 10 CFR 431.192. DOE is
also consolidating all references to
partial load operation in 10 CFR
431.192, 10 CFR 431.196, and appendix
A to the defined ‘‘per-unit load’’ term.
b. Terminal
In the May 2019 NOPR, DOE
proposed to clarify that load and noload loss measurements should be taken
only at the distribution transformer
terminals, as discussed in section III.F.3.
As such, DOE proposed to define
‘‘terminal’’ to mean ‘‘a conducting
element of a distribution transformer
providing electrical connection to an
external conductor that is not part of the
transformer.’’ 84 FR 20704, 20709. This
definition is based on, but not identical
to, the definition for ‘‘terminal’’ in IEEE
C57.12.80–2010,10 ‘‘IEEE Standard
10 IEEE C57.12.80–2010 is currently listed as
‘‘inactive-reserved’’ which means that this standard
is ‘‘. . . removed from active status through an
administrative process for standards that have not
undergone a revision process within 10 years.’’ (See
E:\FR\FM\14SER2.SGM
Continued
14SER2
51238
Federal Register / Vol. 86, No. 175 / Tuesday, September 14, 2021 / Rules and Regulations
tkelley on DSK125TN23PROD with RULES2
Terminology for Power and Distribution
Transformers.’’ IEEE C57.12.80–2010
defines terminal as ‘‘(A) A conducting
element of an equipment or a circuit
intended for connection to an external
conductor. (B) A device attached to a
conductor to facilitate connection with
another conductor.’’
Howard commented in agreement
with the proposed definition. (Howard,
No. 32 at p.1) NEMA, CDA and HVOLT
preferred DOE to adopt the IEEE
C57.12.80–2010 definition of ‘‘terminal’’
directly. (NEMA, No. 30 at p. 2; CDA,
No. 29 at p. 2; HVOLT, No. 27 at p. 90).
DOE has reviewed the IEEE definition
and while part ‘‘(A)’’ is similar to the
definition proposed in the May 2019
NOPR, part ‘‘(B)’’ does not clarify that
the terminal needs to be external. While
adoption of industry-developed
language would promote further
consistency between the DOE test
procedure and the industry testing
standards, DOE is concerned that the
IEEE definition could be understood to
exclude busbar losses in testing of
distribution transformers because part
(B) of the IEEE definition does not
specify that a terminal is for connection
to an external conductor. A
manufacturer could interpret terminal to
be any conducting element within the
distribution transformer, including a
conducting element between the busbar
and the windings. As a result, DOE is
adopting the definition of ‘‘terminal’’
proposed in the May 2019 NOPR at 10
CFR 431.192 as ‘‘a conducting element
of a distribution transformer providing
electrical connection to an external
conductor that is not part of the
transformer.’’
c. Auxiliary Device
Section 4.5.3.1.2 of appendix A
specifies that during testing, ‘‘measured
losses attributable to auxiliary devices
(e.g., circuit breakers, fuses, switches)
installed in the transformer, if any, that
are not part of the winding and core
assembly, may be excluded from load
losses measured during testing.’’ DOE
has received inquiries from
manufacturers regarding whether
certain other internal components of
distribution transformers are required
by the DOE test procedure to be
included in the loss calculation, or
whether they are considered an
auxiliary device. In the May 2019
NOPR, DOE proposed to address the
prior industry questions and establish a
definition of the term ‘‘auxiliary device’’
www.standard.iee.org). Given that the standard has
not been superseded and is not listed as inactivewithdrawn, DOE is continuing to consider it the
current industry standard on standard terminology
for power and distribution transformers.
VerDate Sep<11>2014
20:08 Sep 13, 2021
Jkt 253001
based on a specific list of all
components and/or component
functions that would be considered
auxiliary devices and, therefore, be
optionally excluded from measurement
of load loss during testing. 84 FR 20704,
20709.
The auxiliary device examples listed
at section 4.5.3.1.2 of appendix A
(circuit breakers, fuses, and switches) all
provide protective function, but do not
directly aid the transformer’s core
function of supplying electrical power.
Additionally, the term ‘‘device’’
indicates a localized nature, rather than
a diffuse system or property of the
transformer.
DOE proposed to define ‘‘auxiliary
device’’ to mean ‘‘a localized
component of a distribution transformer
that is a circuit breaker, switch, fuse, or
surge/lightning arrester.’’ DOE requested
comment on the proposed definition, if
any components needed to be added or
removed from the listed auxiliary
devices, and whether it is appropriate to
include functional component
designations as part of a definition. Id.
CDA and HVOLT stated that the
proposed definition was adequate.
(CDA, No. 29 at p.2; HVOLT, No. 27 at
p. 90) Howard commented that the four
components listed are sufficient and a
functional designation is not needed.
(Howard, No. 32 at p.1) NEMA
commented that the current definitions
are adequate and that it is not necessary
to define auxiliary device. (NEMA, No.
39 at p.2) NEMA did not specify what,
if any, aspects of the proposed
definition would be inadequate.
Moreover, prior inquiries from industry
indicate that the definition of ‘‘auxiliary
device’’ would benefit from further
detail. DOE did not receive any
comment suggesting that the proposed
definition is inadequate. DOE is
adopting the definition of auxiliary
device in this final rule as proposed.
3. Updated Definitions
a. Low-Voltage Dry-Type Distribution
Transformer
EPCA defines a ‘‘low-voltage dry-type
distribution transformer’’ as ‘‘a
distribution transformer that—(1) Has
an input voltage of 600 volts or less; (2)
is air-cooled; and (3) does not use oil as
a coolant.’’ 42 U.S.C. 6291(38).
In the May 2019 NOPR, DOE
proposed to update the definition for
‘‘low-voltage dry-type distribution
transformer’’ by replacing the term ‘‘oil’’
with ‘‘insulating liquid’’ within the
definition, in conjunction with DOE’s
proposal to consolidate multiple terms
to ‘‘insulating liquid,’’ as described in
section III.B.2. 84 FR 20704, 20709. DOE
PO 00000
Frm 00010
Fmt 4701
Sfmt 4700
proposed this update to reflect that the
term is inclusive of all insulating
liquids, including those identified in
IEEE C57.12.90–2015. Id.
Howard, CDA, and HVOLT generally
supported using the broader term
‘‘insulating liquid’’ rather than ‘‘oil.’’
(Howard, No. 32 at p. 1; CDA, No. 29
at p. 2; HVOLT, No. 27 at p.91) NEMA
recommended harmonizing the
definition with the definition provided
in IEEE C57.12.80–2010. (NEMA, No. 30
at p. 3) IEEE defines a ‘‘low-voltage drytype distribution transformer’’ to mean
‘‘a distribution transformer that—(1) Has
an input voltage of 600 volts or less; (2)
Has the core and coil assembly
immersed in a gaseous or drycompound insulating medium.’’
Of the three components of EPCA’s
definition of ‘‘low-voltage dry-type
distribution transformer’’, the first
component (‘‘Has an input voltage of
600 volts or less’’) was not proposed for
revision by either the May 2019 NOPR
or by commenters. 42 U.S.C. 6291(38).
This first component of the definition is
left unchanged by this final rule.
Whereas the first component of the
definition addresses the ‘‘low-voltage’’
portion of term ‘‘low-voltage dry-type
distribution transformer’’, the second
and third components (‘‘is air-cooled’’;
‘‘does not use oil as a coolant’’) combine
to describe the manner in which LVDTs
dissipate heat and collectively address
the ‘‘dry-type’’ portion of the term. The
comment from NEMA (suggesting that
DOE amend the definition to reference
the core and coil assembly being
‘‘immersed in a gaseous or drycompound insulating medium’’)
indicates that industry generally
considers the descriptors ‘‘air cooled;
does not use oil as a coolant’’ to be
synonymous with ‘‘immersed in a
gaseous or dry-compound insulating
medium.’’ The revision suggested by
NEMA would also be consistent with
DOE’s terminology for addressing ‘‘dry
type’’ in the definition of ‘‘mediumvoltage dry-type distribution
transformer’’, which DOE defines as a
distribution transformer in which the
core and coil assembly is immersed in
a gaseous or dry-compound insulating
medium, and which has a rated primary
voltage between 601 V and 34.5 kV. 10
CFR 431.192.
After further consideration of the May
2019 NOPR proposal, and consideration
of comments from interested parties in
response to that proposal, this final rule
revises the definition of ‘‘low-voltage
dry-type distribution transformer’’ to
mean ‘‘a distribution transformer that
has an input voltage of 600 volts or less
and has the core and coil assembly
immersed in a gaseous or dry-
E:\FR\FM\14SER2.SGM
14SER2
Federal Register / Vol. 86, No. 175 / Tuesday, September 14, 2021 / Rules and Regulations
compound insulating medium.’’ This
revised wording harmonizes with the
industry definition and implements
consistent terminology across both
varieties of dry-type distribution
transformers (i.e., low-voltage and
medium-voltage).
tkelley on DSK125TN23PROD with RULES2
b. Reference Temperature
The reference temperature is the
temperature at which the transformer
losses must be determined, and to
which such losses must be corrected if
testing is performed at a different
temperature. As currently defined at 10
CFR 431.192, ‘‘reference temperature’’
means 20 °C for no-load loss, 55 °C for
load loss of liquid-immersed
distribution transformers at 50 percent
load, and 75 °C for load loss of both
low-voltage and medium-voltage drytype distribution transformers, at 35
percent load and 50 percent load,
respectively.
In the May 2019 NOPR, DOE
proposed to update the definition for
‘‘reference temperature’’ by removing
references to the numerical temperature
values required for certification with
energy conservation standards. 84 FR
20704, 20709. DOE proposed to retain
the conceptual definition of reference
temperature and to include in appendix
A the numerical temperature values for
certification with energy conservation
standards. The updated definition
would allow use of the term reference
temperature outside the context of
conditions required for certification
with energy conservation standards (i.e.,
voluntary representations at additional
temperature values, as described in
section III.D.2.b). DOE proposed
‘‘reference temperature’’ to mean the
temperature at which the transformer
losses are determined, and to which
such losses must be corrected if testing
is performed at a different temperature.
Howard and NEMA both supported
the updated definition. (Howard, No. 32
at p. 1; NEMA, No. 30 at p. 3).
CDA and HVOLT commented that the
reference temperature for ambient has
been used throughout the industry as 20
ßC and that letting that number float to
other reference temperatures would be
confusing to industry. (CDA, No. 29 at
p. 2; HVOLT, No. 27 at p. 91).
The reference temperature in the test
procedure does not necessarily refer to
the ambient temperature, because
testing can be performed at a different
temperature, with the results corrected
to reflect testing at the defined reference
temperature. DOE did not propose
changes to any of these values for the
purpose of certification with energy
conservation standards.
VerDate Sep<11>2014
20:08 Sep 13, 2021
Jkt 253001
The updated definition does not
specify particular temperature values in
order to accommodate the use of the
term in a context other than only the
conditions required for certification and
compliance, i.e., voluntary
representations of efficiency at
temperatures or PULs different from
those specified in appendix A. For
example, a manufacturer voluntarily
representing efficiency at 100 percent
PUL would correct to a reference
temperature that is reflective of the
distribution transformer temperature
rise at 100 percent PUL.
DOE is adopting the updated
definition of ‘‘reference temperature’’ in
10 CFR 431.192 as proposed.
D. Per-Unit Load Testing Requirements
The efficiency of distribution
transformers varies depending on the
PUL at which the distribution
transformer is operated. DOE’s energy
conservation standards for distribution
transformers at 10 CFR 431.196
prescribe the PUL at which the
efficiency of the distribution
transformer must be determined and
certified to DOE (i.e., the ‘‘standard
PUL’’). The standard PUL is intended to
represent the typical PUL experienced
by in-service distribution transformers
over their lifetime. For liquid-immersed
distribution transformers and mediumvoltage dry-type distribution
transformers, the equipment efficiency
is certified at a standard PUL of 50
percent. For low-voltage dry-type
distribution transformers, the efficiency
is certified at a standard PUL of 35
percent. These values were adopted in
the April 2006 Final Rule from NEMA
TP 2–1998. 71 FR 24972.
As described previously, appendix A
does not require testing of the
distribution transformer at the standard
PUL; rather, the standard PUL is
required only for certification of
efficiency. Testing can be performed at
any PUL, with the results
mathematically adjusted to reflect the
applicable standard PUL. Section 5.1 of
appendix A provides equations to
calculate the efficiency of a distribution
transformer at any PUL based on the
testing of the distribution transformer at
a single PUL. Current industry practice
is to test at 100 percent PUL and
mathematically determine the efficiency
at the applicable standard PUL. (NEMA,
No. 30 at p. 4).
The efficiency of distribution
transformers over the duration of its
lifetime and across all installations
cannot be fully represented by a single
PUL. A given transformer may be highly
loaded or lightly loaded depending on
its application or variation in electrical
PO 00000
Frm 00011
Fmt 4701
Sfmt 4700
51239
demand throughout the day. DOE has
previously acknowledged that
distribution transformers may
experience a range of loading levels
when installed in the field. 78 FR
23336, 23350 (April 18, 2013).
DOE previously acknowledged that
the majority of stakeholders, including
manufacturers and utilities, support
retention of the current testing
requirements; and DOE determined that
its existing test procedure provides
results that are representative of the
performance of distribution
transformers in normal use. Id. DOE
further determined that potential
improvements in testing precision that
might result from testing at multiple
PULs would be outweighed by the
complexity and the burden of requiring
testing at different loadings depending
on each individual transformer’s
characteristics. Id.
In the May 2019 NOPR, DOE stated
that it had considered (1) revising the
single standard PUL 11 to a multiplePUL weighted-average efficiency metric,
(2) revising the single standard PUL to
an alternative single test PUL metric
that better represents in-service PUL, or
(3) maintaining the current single test
PUL specifications. 84 FR 20704, 20714.
DOE tentatively determined that the
range of in-service PUL is diverse, and
that the available information describing
in-service PUL is inconclusive. Id. DOE
was unable to show that any alternative
standard PUL(s) would be more
representative than the current standard
PUL and therefore did not propose an
amendment of the standard PULs. Id.
DOE proposed, however, to allow for
voluntary representations to be made at
PULs other than the standard PUL. Id.
The following sections summarize
comments received on each of these
considerations, as well as DOE’s
responses and conclusions.
1. Multiple-PUL Weighted-Average
Efficiency Metric
In the past, DOE has considered a
multiple-PUL efficiency metric in
contemplating whether a weightedaverage efficiency metric composed of
efficiency at more than one PUL may
better reflect how distribution
transformers operate in service. 84 FR
20704, 20713. In the May 2019 NOPR,
DOE expressed concern that a multi11 In the May 2019 NOPR, DOE used the term
‘‘test PUL’’ to refer to ‘‘standard PUL’’ as used in
this final rule. The term ‘‘standard PUL’’ better
reflects that this is referring to the PUL at which
the energy efficiency must be determined for the
purpose of complying with the energy conservation
standards at 10 CFR 431.196. As described
previously in this document, testing can be
performed at any PUL, with the results corrected to
the standard PUL.
E:\FR\FM\14SER2.SGM
14SER2
51240
Federal Register / Vol. 86, No. 175 / Tuesday, September 14, 2021 / Rules and Regulations
tkelley on DSK125TN23PROD with RULES2
PUL metric could increase burden on
manufacturers and create challenges in
consumer education without being more
representative of in-service PULs than
the current metric. Id.
The Efficiency Advocates suggested
that DOE request transformer loading
data from IEEE’s Transformer
Committee to analyze the empirical data
describing PUL variation. (Efficiency
Advocates, No. 34 at p. 2) The
Efficiency Advocates, asserted that the
IEEE data shows a wide variation in
PUL and that DOE should consider a
weighted average PUL efficiency metric
in the DOE test procedure. (Efficiency
Advocates, No. 34 at p. 2).
DOE has considered a metric based on
a weighted average of a transformer’s
efficiency at multiple different PULs.
Different weighting schemes are
possible. For example, the measured
efficiencies could be weighted by the
fraction of operating hours expected at
each PUL over the lifecycle of a
distribution transformer.
Generally, distribution transformer
losses are presented within the industry
as consisting of no-load losses, which
are approximately constant with PUL,
and load losses, which scale nearly
quadratically with PUL. Under that set
of mathematical assumptions, any
particular multi-PUL metric 12 could
alternatively be represented by a singlePUL metric that would yield the same
efficiency value. In other words, any
multi-PUL metric would be replaceable
by a certain single-PUL metric. Given
this, DOE finds no advantage in
adopting a multi-PUL metric for
distribution transformers. A multi-PUL
metric would represent a slightly more
complex way of arriving at the same
result that could be derived from a
carefully chosen single-PUL metric. As
a result, DOE is not adopting a multiPUL metric for distribution transformers
in this final rule.
2. Single-PUL Efficiency Metric
As stated previously, DOE requires
distribution transformers’ efficiency to
be certified at a standard PUL of 50
percent for liquid-immersed distribution
transformers and medium-voltage drytype distribution transformers and 35
percent for low-voltage dry-type
distribution transformers. 10 CFR
431.196.
In the May 2019 NOPR, DOE stated
that it had considered revising the
single standard PUL to an alternative
single test PUL that better represents inservice PUL. 84 FR 20704, 20714. DOE
tentatively determined that the range of
12 Specified as a set of any number of pairs of PUL
values and weighting coefficient at that PUL.
VerDate Sep<11>2014
20:08 Sep 13, 2021
Jkt 253001
in-service PUL values is diverse, and
that the available information describing
in-service PUL is inconclusive. Id. DOE
was unable to conclude that any
alternative standard PUL(s) would be
more representative than the current
standard PUL and, therefore, did not
propose to amendment the standard
PULs. Id.
In response to the May 2019 NOPR,
DOE received comments arguing both
for and against revising the single-PUL
metric; these are discussed in detail in
sections III.D.2.a and III.D.2.b. These
comments comport with the idea that
distribution transformers’ in-service
PULs reflect diverse operating
conditions. After considering the
comments brought forward by
stakeholders and discussed in sections
III.D.2.a and III.D.2.b. DOE has
concluded that revising the PUL is not
justified at this time for two reasons.
First, there is significant long-term
uncertainty regarding what standard
PUL would correspond to a
representative average use cycle for a
distribution transformer given their long
lifetimes.13 The publicly available data
effectively amounts to a single year from
a few distribution transformer
customers. Given the uncertainty
associated with future distribution
transformer loading, DOE is unable to
conclude with certainty that a given
alternative single-PUL efficiency metric
is more representative than the current
standard PUL.
Second, given the uncertainty of
future loading distributions, there may
be greater risk in selecting too low a
standard PUL than too high a standard
PUL for two reasons. First, the quadratic
nature of load loss means that absolute
power consumption grows more quickly
on the high side of the standard PUL
than on the low side. Second,
divergence of the costs associated with
different categories of loss means that
there is greater risk associated with
selecting too low a standard PUL than
too high.
Accordingly, in this final rule, DOE is
maintaining the current standard PUL
specifications. DOE is centralizing the
PUL specifications in appendix A, as
discussed in section III.F.1.
DOE considered several factors in
determining not to revise the current
standard PUL requirements in this final
rule. In section III.D.2.a, DOE reviews
publicly available in-service PUL data.
In sections III.D.2.b and III.D.2.c, DOE
considers uncertainty in estimates of
13 DOE determined in the April 2013 ECS Final
Rule as having an average lifespan of 32 years, and
in many cases they may have an in-service lifetime
that is significantly longer. 78 FR 23336, 23377.
PO 00000
Frm 00012
Fmt 4701
Sfmt 4700
future load growth, its effects on
distribution transformers’ in-service
PULs, and the respective risks
associated with both under- and
overestimating actual future in-service
PULs.14
a. Publicly Available Transformer Load
Data
In response to the May 2019 NOPR,
the Efficiency Advocates suggested that
DOE use IEEE’s Advanced Meter
Information (‘‘AMI’’) data to inform the
PUL rulemaking. (Efficiency Advocates,
No. 34 at p. 1) Citing IEEE’s Distribution
Transformer Subcommittee Task Force’s
(‘‘IEEE–TF’’) estimates of average inservice PUL for medium-voltage, liquidfilled transformers, the Efficiency
Advocates suggest in-service PULs are
significantly lower than the current
standard PULs. (Efficiency Advocates,
No. 34 at p. 2) The Efficiency Advocates
recommend, if DOE does not base its
analysis on AMI data, that DOE use PUL
values of 35 percent for liquidimmersed transformers, 25 percent for
low-voltage dry-type distribution
transformers, and 38 percent for
medium-voltage dry-type distribution
transformers. (Efficiency Advocates, No.
34, at pp. 2–3).
Cargill commented that the IEEE–TF
data suggests average annual loading is
less than 30 percent of the ‘‘Peak
Annual Load’’. (Cargill, No. 28 at p. 1)
Cargill stated that even in the most
conservative case of peak load equaling
nameplate load, the resulting average
PUL would be less than 30 percent.
(Cargill No. 28 at p. 1) NEMA
commented that it is not aware of any
changes in the field that would justify
modifying the current PUL levels.
(NEMA, No. 30 at p. 4).
DOE examined the data made
available through IEEE–TF.15 All of the
data available through the IEEE–TF is
for liquid-immersed distribution
transformers; DOE did not separately
receive updated loading data for LVDTs
or MVDTs.
DOE has identified several limitations
and questions regarding the data made
available through the IEEE–TF. First and
foremost, none of the datasets of AMI
data referred to by the Efficiency
Advocates are measured transformer
loads, rather they are samples of
customer load connected to specific
transformers. Additionally, each dataset
14 See: Section 2.3 of Chapter 2. Analytical
Framework, Comments from Interested Parties, and
DOE Responses of the Prelim Technical Support
Document (TSD) at Docket No. EERE–2019–BT–
STD–0018–0022.
15 See: grouper.ieee.org/groups/transformers/
subcommittees/distr/EnergyEfficiency/F20DistrTransfLoading-Mulkey.pdf.
E:\FR\FM\14SER2.SGM
14SER2
Federal Register / Vol. 86, No. 175 / Tuesday, September 14, 2021 / Rules and Regulations
tkelley on DSK125TN23PROD with RULES2
presented during the IEEE–TF is a
sample of customers’ AMI data (i.e., not
a complete population of distribution
transformer load data), and each carries
questions regarding the sampling
methodology, representativeness, and
completeness. DOE does not know what
criteria were used to select the sample
from each existing population of utility
customers. Further, each data set was
also incomplete in terms of missing
meter readings, non-sequential metering
periods, or missing unmetered loads (for
example, exterior building lighting,
utility owned equipment, and street
lighting are usually on separate
unmetered tariffs 16). These unmetered
loads, on separate unmetered tariffs,
would not be accounted for in the AMI
data, and would produce the effect of
underestimating in-service PUL for a
given transformer.
DOE examined the largest individual
sample of data, from Dominion Energy,
Inc., which consisted of a year of hourly
and sub-hourly readings for roughly
60,000 AMI meters connected to
distribution transformers aggregated
into zip codes for parts of Virginia and
North Carolina.17 After removing data
from AMI meters that were incomplete,
or that had the quality issues
highlighted in the presentation to the
IEEE–TF (loads with peak-loads that
were several times higher than the
connected transformers capacity), DOE
found that the average root mean square
(RMS) load, as a function of transformer
nameplate capacity, over the year in
question (2018) was substantially higher
than the 10 percent mode value
presented to the IEEE–TF. DOE found
that average RMS in-service PUL for the
transformers subject to the DOE test
procedure and energy conservation
standards was 27.8 percent.18
After reviewing the IEEE–TF AMI
data, DOE agrees with the Efficiency
Advocates and Cargill that the current
data indicates that the average, current,
in-service, liquid-immersed distribution
transformer loading is lower than the
standard PUL. However, the data also
indicates that distribution transformers
operate over a diverse range of operating
conditions. The data shows that a single
customer does not operate a distribution
transformer at a single constant PUL.
Further, a given distribution transformer
16 J. Triplett, S. Rinell and J. Foote, ‘‘Evaluating
distribution system losses using data from deployed
AMI and GIS systems,’’ 2010 IEEE Rural Electric
Power Conference (REPC), 2010, pp. C1–8, doi:
10.1109/REPCON.2010.5476204.
17 Zip codes were used to aggregate customer AMI
data to anonymize the data.
18 See: Chapter 7. Energy Use Analysis of the
Prelim TSD at Docket No. EERE–2019–BT–STD–
0018–0022.
VerDate Sep<11>2014
20:08 Sep 13, 2021
Jkt 253001
model may be used at different PULs by
different customers. The realities of the
typical range of operations, and issues
of data quality and sample completeness
raise uncertainties regarding the
representativeness of the average PUL
values presented by the IEEE–TF.
DOE also notes that while the IEEE–
TF AMI data provides valuable insight
into the in-service PUL of liquidimmersed distribution transformers, no
equivalent, publicly available data has
been presented for medium-voltage and
low-voltage dry-type distribution
transformers.
Another complicating factor in the
representativeness of the currently
available data is that the IEEE–TF AMI
data only covers a single year of
distribution transformer lifespans.
Distribution transformers have lifespans
of several decades and as such, DOE
needs to consider not only the diversity
of operating conditions that distribution
transformer currently experience but the
entire range of operating conditions a
distribution transformer would
experience in its lifespan. Additionally,
most of the available data are from
similar geographies, on the Atlantic
coast, which would experience similar
climatic sensitivities, which is not
representative of the Nation as a whole.
Stakeholders identified several possible
factors that could significantly impact
distribution transformer loading in the
short to medium term, as discussed in
section III.D.2.b.
b. Load Growth Uncertainties
DOE received several comments from
stakeholders in response to the May
2019 NOPR on the topic of future load
growth on distribution transformers.
Cargill supported maintaining the
current standard PUL, asserting that as
future transformer loads increase,
increased transformer efficiency could
be realized due to conventional core
steel having a peak efficiency between
45 and 55 percent PUL. (Cargill, No. 28
at p. 1) Cargill also suggested that
utilities are increasingly considering
overloading transformers during peak
demand with the objective of replacing
larger mineral-oil-filled transformers
with smaller, cheaper transformers.
Such an approach, Cargill asserts, could
increase average loading to 50 percent
and support retaining the current
standard PULs. (Cargill, No. 28 at p. 2)
The Efficiency Advocates commented
that increased adoption of photovoltaic
generation (‘‘PV’’) will depress peak
demand, as it has done in California.
The Efficiency Advocates also
commented that increasing adoption of
electric vehicles (‘‘EVs’’) is unlikely to
contribute to peak demand and load
PO 00000
Frm 00013
Fmt 4701
Sfmt 4700
51241
growth because it is in utilities’ interest
to encourage off-peak charging.
(Efficiency Advocates, No. 34 at p. 3)
Further, the Efficiency Advocates
recommended against DOE’s continued
use of a 1 percent average annual
increase, claiming that based on past
experience and future projections, load
growth of this magnitude is unlikely.
(Efficiency Advocates, No. 34 at pp. 4)
Finally, the Efficiency Advocates
asserted that increases in demand due to
population growth will be met with the
installation of new transformers, rather
than increasing loads on existing
transformers. (Efficiency Advocates, No.
34 at p. 2–3).
HVOLT and CDA commented that
standard PUL changes are not needed
right now, but that EV charging in the
future may increase loading. (CDA, No.
29 at p. 89; HVOLT, No. 27 at p. 94).
Load growth has always been, and
continues to be, difficult to predict.
Stakeholders disagreed as to what future
distribution transformer loading would
be expected. While IEEE–TF data
suggests that the current in-service PUL
is lower than the standard PUL, the
extent to which distribution transformer
load will change over time is unclear.
Distribution transformers were
evaluated in the April 2013 ECS Final
Rule as having an average lifespan of 32
years, and in many cases they may have
an in-service lifetime that is
significantly longer. 78 FR 23336,
23377. The long lifetime of distribution
transformers means that many will
operate through multiple economic,
social, or climate-driven events that
could affect the average in-service PUL
on individual transformers.
In response to Cargill, while many
conventional core steel transformers
have a peak efficiency between 45 and
55 percent, this is not generally the case
across the entire market and may in part
be driven by the 50 percent standard
PUL specified in the DOE test
procedure. Given an alternative
standard PUL, conventional core steel
transformers could be designed with
peak efficiencies at other values.
Further, while some utilities may be
considering overloading transformers as
standard operating practice and could
therefore replace larger distribution
transformers with smaller distribution
transformers, thereby increasing the inservice PUL of these distribution
transformers, DOE does not have any
data to substantiate Cargill’s claim that
this practice is actually occurring or is
expected to occur.
In response to the Efficiency
Advocates, DOE generally agrees that
PV generation as a resource at the level
of the transmission grid can both reduce
E:\FR\FM\14SER2.SGM
14SER2
51242
Federal Register / Vol. 86, No. 175 / Tuesday, September 14, 2021 / Rules and Regulations
tkelley on DSK125TN23PROD with RULES2
the overall generation required to serve
a population and have potential impacts
of reducing peak-demand in areas where
there is enough solar resource to do so.
However, when considered at the level
of the load(s) being served by individual
distribution transformers, PV generation
(or other demand-side generation) will
generally reduce the load on the
transformer only by the quantity of
energy consumed on the secondaryservice side, (i.e., the customer
connected side), of the transformer.
Unless the PV generation is not gridtied, any surplus energy being
transformed from secondary-service
voltages to primary-service voltages and
fed back into the grid for distribution
would contribute to the average load of
the transformer. Depending on the
quantity of surplus energy being fed
back into the grid, PV generation could
have the effect of either decreasing or
increasing the average PUL on an
individual distribution transformer.
Further, if surplus energy is fed back
into the grid during peak times, it could
have the impact of increasing both peak
load and average load. A recent study by
National Renewable Energy Laboratory
(‘‘NREL’’) and Los Angeles Department
of Water and Power (‘‘LADWP’’), Los
Angeles 100% Renewable Energy Study
(‘‘LA100’’), researching the needs to
serve the greater city of Los Angeles
with 100 percent renewable energy,
estimated that 80 percent of existing
distribution feeders would need to be
upgraded due to occurrences of one or
more overloading violations with the
connected transformers.19 Integrating
PV or other distributed-generation in a
dispatchable manner is a technically
complex task, and at the transmission
level can reduce overall electricity
demands; however there is also the
potential that loads may rise on some
distribution circuits (and connected
distribution transformers) to meet these
transmission reductions.
The Efficiency Advocates’ claim that
EV impacts on peak electricity demand
and transformer loads may be small,
given the assertion that it is in the
electric utility’s interest to promote offpeak charging, is incomplete. The
Efficiency Advocates cited an article in
support of their assertion that ‘‘at a
macro scale, EVs appear to pose only a
modest burden on the electric grid’’.20
19 Palmintier, Bryan, Meghan Mooney, Kelsey
Horowitz, et al. 2021. ‘‘Chapter 7: Distribution
System Analysis.’’ In the Los Angeles 100%
Renewable Energy Study, edited by Jaquelin
Cochran and Paul Denholm. Golden, CO: National
Renewable Energy Laboratory. NREL/TP–6A20–
79444–7. www.nrel.gov/docs/fy21osti/79444-7.pdf.
20 J. Coignard, P. MacDougall, F. Stadtmueller and
E. Vrettos, ‘‘Will Electric Vehicles Drive
VerDate Sep<11>2014
20:08 Sep 13, 2021
Jkt 253001
However, this position oversimplifies
the relationship between connected
loads, the distribution grid, and
transmission grid. The article cited by
the Energy Advocates cautions that at a
micro scale, EVs represent a significant
addition to traditional household loads;
and further states that the addition of a
level 2 residential EV charging station
contributes a load similar to an
additional house on the grid.21
While there are likely benefits to
promoting off-peak charging, or other
types of structured charging schemes,
EV charging is difficult to predict and
model because EV adoption is still in
the early stages. While some utility
programs have been successful at
shifting EV loads from peak to off-peak
times using time-of-use rates or specific
EV charging electricity tariffs, offsetting
system peak capacity demands, the
additional load required to charge an EV
during non-peak times will still
contribute to the overall average
transformer PUL. Analysis conducted
for the LA100 study indicates, under the
‘‘moderate’’ projection, that electrical
demand for transportation will be one of
the largest contributors to distribution
load growth over their analysis period
(2020 through 2045).22 The LA100 study
addresses the load impacts on utility
distribution systems, which would be
served by liquid-immersed mediumvoltage distribution transformers, it does
not address the potential impacts to
commercial and industrial customers
who deploy dry-type distribution
transformers. The impact of EV driven
load growth on dry-type distribution
transformers could also be significant,
particularly if EVs are charged on
circuits without upgrades to the serving
low- or medium-voltage dry-type
distribution transformers.
In response to the September 2017
RFI, the Efficiency Advocates
challenged DOE’s assertion that the
record supports a 50 percent PUL for
liquid-immersed distribution
transformers (on the basis that
increasing future load growth at the rate
of one percent per-year would result in
in-service PULs that would eventually
converge with the test standard PUL
over time was calculated was
incorrectly). In the September 2017 RFI
Distribution Grid Upgrades?: The Case of
California,’’ in IEEE Electrification Magazine, vol. 7,
no. 2, pp. 46–56, June 2019, doi: 10.1109/
MELE.2019.2908794.
21 Ibid.
22 Hale, Elaine, Anthony Fontanini, Eric Wilson,
et al. 2021. ‘‘Chapter 3: Electricity Demand
Projections.’’ In the Los Angeles 100% Renewable
Energy Study, edited by Jaquelin Cochran and Paul
Denholm. Golden, CO: National Renewable Energy
Laboratory. NREL/TP–6A20–79444–3.
www.nrel.gov/docs/fy21osti/79444-3.pdf.
PO 00000
Frm 00014
Fmt 4701
Sfmt 4700
DOE asserted that with a one-percent
future growth rate over time, thencurrent observed RMS PUL values
would approximately converge to the
standard PUL values. 82 FR 44347,
44349. In response to the load growth
assertions from the Efficiency
Advocates, DOE examined the trend in
sales of electricity to customers made
available by the Annual Energy Outlook
(AEO) in its Electric Power Monthly
periodical.23 DOE first examined the
time period highlighted by the
Efficiency Advocates and confirms that
2018 was a year in which sales were
much higher than in the preceding
period from 2011 through 2017. DOE
notes that while 2018 had the greatest
year-on-year growth over this period,
there were other years with positive
growth, and the average year-on-year
growth for the period between 2011
through 2018 was 0.4 percent. DOE also
finds that the time period highlighted by
the Efficiency Advocates is not
sufficient for this analysis given that the
average in-service lifetime for
distribution transformers is 32 years. As
such, DOE takes a longer view of the
trend of available data when
considering the impacts of load growth.
When examining the 10-year rolling
average of year-on-year growth for the
period 2010 through 2020, it can be
observed that sales of electricity
increased for every period, except for
the periods ending in 2017 and 2020,
with an average year-on-year increase of
0.3 percent.24
As mentioned, the Efficiency
Advocates assert that future growth in
electricity sales will be driven by
population growth, which tends to
cause grid expansion and the
installation of new transformers, rather
than to increase loads on existing
transformers. (Efficiency Advocates, No.
34 at p. 2–3) DOE partially agrees with
the Efficiency Advocates, that load
growth from new construction would be
met with new transformers. DOE must
consider that the additional factors that
drive load growth (e.g., weather events,
expanding populations, increased
electrification), impact all connected
distribution transformers, not just those
installed to provide service to new
construction, and therefore must
consider the effect of load growth’s
23 Energy Information Administration, Electric
Power Monthly, www.eia.gov/electricity/monthly/.
24 Energy Information Administration, {Electric
Power Monthly December 1997, DOE/EIA–0226(97/
12); Electric Power Monthly December 2011, DOE/
EIA–0226(2011/12); Electric Power Monthly
December 2017; Electric Power Monthly December
2020}, www.eia.gov/electricity/monthly/, See for
each of the four listed time periods: Table 5.1. Sales
of Electricity to Ultimate Customers: Total by EndUse Sector.
E:\FR\FM\14SER2.SGM
14SER2
Federal Register / Vol. 86, No. 175 / Tuesday, September 14, 2021 / Rules and Regulations
tkelley on DSK125TN23PROD with RULES2
impact on a transformer’s typical use
cycle.
The Efficiency Advocates requested
DOE respond to their comment on the
September 2017 RFI, where the
Efficiency Advocates challenged DOE’s
assertion that, for liquid-immersed
distribution transformers, future load
growth (at the rate of one percent peryear), would result in in-service PULs
that would eventually converge with the
standard PUL over time, and stated that
the in-service PUL was calculated
incorrectly. (Efficiency Advocates, 0015
at p. 1) In the September 2017 RFI, DOE
asserted that, on average, the initial
(first year) RMS PUL for liquidimmersed transformers ranged from 34
and 40 percent for single- and threephase equipment, respectively, with a
one percent annual increase over the life
of the transformer to account for
connected load growth. This resulted in
a lifetime average PUL of 49 and 56
percent for single- and three-phase
liquid-immersed transformers,
respectively. And that it was consistent
with the current test procedure
requirements of rating liquid-immersed
transformers at 50 percent PUL. 86 FR
44349. After further analysis of the data,
DOE agrees with the Efficiency
Advocates that the load growth impact
on PUL in the September 2017 RFI was
incorrectly calculated. DOE agrees the
load growth rates needed to support the
assertion that the in-service PUL would
converge with the standards PUL over
the transformers typical lifetime in the
September 2017 RFI would need to be
greater than the proposed one percent
per-year. While the conclusions drawn
in the September 2017 RFI cannot be
supported, recent market and policy
changes since the publication of the RFI
indicate that the premise that there are
uncertainties and concerns associated
with future load growth, continue to be
valid.
c. Risks Associated With Current and
Future Losses
Given the diversity of conditions
under which distribution transformers
are currently operated and the
uncertainty as to how future changes in
connected loads will affect in-service
PULs, DOE must consider how a single
standard PUL would fare in both
circumstances in which it overestimates
and underestimates the in-service PUL.
As discussed in section III.D.1, a
distribution transformer’s efficiency is
determined as a function of the total
losses at the standard PUL. A
distribution transformer’s total losses at
the standard PUL are the sum of its noload losses and load losses at the
standard PUL. No-load losses are
VerDate Sep<11>2014
20:08 Sep 13, 2021
Jkt 253001
approximately constant with the PUL
and load losses increase quadratically
with PUL.
Every distribution transformer has a
PUL for which efficiency peaks, where
no-load and load losses happen to be
equal. While there is no prescribed PUL
at which this must occur, often, as a
result of optimizations in the
manufacturing process, transformers are
most efficient at, or near, the DOE
prescribed standard PUL. Distribution
transformers that have a peak efficiency
at PUL values greater than the average
in-service PUL overemphasize load
losses and distribution transformers that
have a peak efficiency less than the
average in-service PUL overemphasize
no-load losses relative to transformer
designs with equivalent total losses that
peak at the in-service PUL. The
asymmetry in rate of loss change—the
losses rise faster at PULs greater than
the standard PUL than they fall at PULs
less than the standard PUL—contributes
to the conclusion that the risk of
selecting a suboptimal standard PUL is
greater on the low side than on the high
side. Efficiency falls in proportion to the
degree to which in-service PUL diverges
from standard PUL. Because a lower inservice PUL corresponds (on a singleunit basis) to a lower absolute quantity
of energy, however, a given loss of
efficiency equates to a greater absolute
quantity of energy when the in-service
PUL exceeds standard PUL.25
As stated in section III.D.2.a, the
Efficiency Advocates recommend DOE
select a lower standard PUL to better
align with the AMI data. (Efficiency
Advocates, No. 34, at pp. 2–3) DOE
notes that the maximum technologically
feasible design options analyzed in the
April 2013 Final Rule consist of
distribution transformers that have a
peak efficiency well below the standard
PUL (often times below 20 percent
PUL). 78 FR 23337. This indicates that
distribution transformers can be built
that perform well at both the in-service
PULs cited by the Efficiency Advocates
and meet efficiency standards at the
current standard PUL. Energy savings
achieved through the energy
conservation standard rulemaking at the
current PUL have less of this
asymmetric risk because they do not
discount load losses to the same degree
as a lower PUL.
In addition to considering the energy
savings potential of the standard PUL
overestimating and underestimating inservice PUL, DOE also considered the
25 See: Section 2.3 of Chapter 2. Analytical
Framework, Comments from Interested Parties, and
DOE Responses of the Prelim TSD at Docket No.
EERE–2019–BT–STD–0018–0022.
PO 00000
Frm 00015
Fmt 4701
Sfmt 4700
51243
financial value of losses to consumers
associated with overestimating and
underestimating in-service PULs.
i. Peak Coincidence Risks
The Efficiency Advocates suggested
that it in the best interest of utilities to
pursue programs to mitigate risks
related to peak demands. (Efficiency
Advocates, No. 34 at p. 3) Demand
response programs can help flatten
peaks at the grid, distribution, and
individual consumer levels. A
simplified example is a demand
response program which promotes peakload shifting, wherein utility ratepayers
defer or forego electrical consumption
during times when the system is
peaking. This may have a bottom-up
effect of reducing peak power through
individual distribution transformers by
reducing peak generation. Owners of
distribution transformers typically face
different costs depending on overall
demand, which influences the mix of
generation and storage they may deploy
to meet the demand. Large electrical
consumers (who with electrical utilities
generally form the total set of
distribution transformer owners), too,
face demand-based cost of electrical
power. In general, marginal cost of
electricity is greater during times of high
demand. This carries implications for
valuing the losses of distribution
transformers. Specifically, load losses
will tend to be costlier for the owner of
the distribution transformers as
proportionally more of them occur
during periods of high demand and
correspondingly higher energy cost.
By their nature, distribution
transformers tend to be ‘‘peakcoincident’’, i.e., the peak load on the
distribution transformers tends to
coincide with peak load on the larger
electrical network. That distribution
transformer loading peaks to when
electrical power costs peak can result in
certain distribution transformer
customers bearing high operating cost
for a small number of peak operating
hours. Distribution transformers
designed without account of this
electrical cost dynamic, optimized for
lower in-service PULs, will operate at
comparatively low efficiency when the
cost of operation is greatest. DOE
recognizes that demand response
programs can reduce the peak-load
impacts. However, because distribution
transformers reflect the load patterns of
their connected loads, the risks of the
high rate of load losses associated with
peak coincidence cannot be fully
controlled by utilities and are
dependent on consumer patterns.
Accordingly, DOE needs to maintain a
E:\FR\FM\14SER2.SGM
14SER2
51244
Federal Register / Vol. 86, No. 175 / Tuesday, September 14, 2021 / Rules and Regulations
PUL which adequately addresses both
high and low in-service loads.
ii. Serving Future No-Load and Load
Losses
In evaluating the financial risk to
consumers of the standard PUL overand underestimating in-service PULs,
and given the long lifespans of
distribution transformers, DOE needs to
consider how future no-load and load
losses will be served.
The way in which future electricity
generation needs will be met has
historically been considered in DOE’s
ECS analyses. However, to the extent
that the choice of metric affects the cost
effectiveness and energy consumption
(both in the aggregate quantity and the
timing of that energy consumption) of
consumers, some background on the
power grid (the operating site of
distribution transformers) is necessary
to understand the broader impacts of
any metric change. Insofar as purchasers
of distribution transformers select on
the basis of first cost, manufacturers
may attempt to minimize first cost
subject to compliance with energy
conservation standards. The specific
distribution transformer design that
minimizes first cost may vary based on
the metric it is being evaluated against.
Thus, selection of standard PUL may
indirectly influence purchase prices and
energy consumption of distribution
transformers.
In the April 2013 ECS Final Rule,
DOE assumed that future power needs
for no-load losses would be met by the
mix of different baseline generation
types in the year of compliance, 2016.
78 FR 23337. At that time, DOE based
its analysis on the data available from
AEO 2012, which indicated a mix of
generation types which was
predominantly served by coal at 26
percent, natural gas combined cycle at
19 percent, renewables and natural gas
combustion turbines both at 15 percent,
with the remainder generation being
met by other generation types.26 DOE
projected that future no-load losses
generation would be met by new
capacity from coal, as it serves
predominantly base load, and natural
gas and renewables serve a mix of
base-, mid-merit and peaking loads.27
DOE assumed that load losses would be
met with simple combustion turbines.28
This resulted in a cost, in terms of
dollars per watt, ($/W) for no-load
losses that was higher than the cost of
load losses. A contributing factor to this
difference is the relatively high
overnight capital cost of large coal
plants, in terms of dollars per megawatt
unit capacity, ($/MW) when compared
to other generating types for
determining the capacity cost
component of the cost of electricity.
However, the current AEO 2021 projects
a very different mix of generating fuel
types, now and into the future, with
retiring coal and, to a lesser degree,
nuclear generation being displaced by
natural gas, in the near-term, and then
renewables in future years. These trends
are shown in Table III.3. This shift in
generating fuels suggests that the future
cost associated with no-load losses and
load losses will be closer in price than
previously estimated as similar
generating units are used to meet both
no-load and load losses.
TABLE III.3—PROJECTED FRACTION OF GENERATION BY FUEL TYPES FOR CERTAIN YEARS
[Percent of total generation]
Year
Coal
(%)
AEO
2010
2015
2020
2025
2030
2035
2040
2045
2050
..............................................................................
..............................................................................
..............................................................................
..............................................................................
..............................................................................
..............................................................................
..............................................................................
..............................................................................
..............................................................................
Natural gas
(%)
Nuclear
(%)
Renewable sources
(%)
Other sources
(%) *
2012 **
2021 †
2012
2021
2012
2021
2012
2021
2012
2021
46
39
40
41
40
40
..............
..............
..............
..............
..............
20
17
16
15
14
12
12
23
26
24
24
25
26
..............
..............
..............
..............
..............
40
35
34
33
34
35
35
20
21
22
21
21
19
..............
..............
..............
..............
..............
20
18
15
14
13
13
12
10
13
13
14
13
14
..............
..............
..............
..............
..............
20
29
34
37
38
39
41
1
1
1
1
1
1
..............
..............
..............
..............
..............
0
0
0
0
0
0
0
tkelley on DSK125TN23PROD with RULES2
* Includes the following generation fuel-type categories: Distributed Generation, Generation for Own Use, Petroleum, Pumped Storage/Other.
** Source: U.S. Energy Information Administration, Annual Energy Outlook 2012, Electricity Electric Power Sector Generation (Case Reference case Region United
States).
† Source: U.S. Energy Information Administration, Annual Energy Outlook 2021, Electricity Electric Power Sector Generation (Case Reference case Region United
States).
As stated previously, in this final rule,
DOE is maintaining the current standard
PUL specifications. DOE is centralizing
the PUL specifications in appendix A,
as discussed in section III.F.1.
Further, the test procedure and
accompanying energy conservation
standards do not preclude
manufacturers from optimizing
distribution transformer performance at
a PUL other than the standard PUL so
long as the unit complies with the
applicable standard when tested at the
standard PUL. While reducing the
standard PUL could in certain cases
have a positive impact on energy
savings, especially for distribution
transformers fabricated with low-loss
core materials such as amorphous steel,
the same energy savings outcome can
often be achieved through amending the
energy conservation standard for
distribution transformers. In other
words, the savings associated with a
potential reduction of standard PUL is
often a byproduct of greater consumer
selection of amorphous-based
transformers, which by chance tend to
both be relatively better at smaller PUL
values and also be more efficient in
absolute terms. Many of the distribution
transformer designs in the
26 Energy Information Administration, Annual
Energy Outlook, 2012, Table 54. Electric Power
Projections by Electricity Market Module Region.
27 See Chapter 7 of the 2013 final rule TSD,
available at https://www.regulations.gov/document/
EERE-2010-BT-STD-0048-0760.
VerDate Sep<11>2014
22:37 Sep 13, 2021
Jkt 253001
PO 00000
Frm 00016
Fmt 4701
Sfmt 4700
accompanying energy conservation
standards preliminary engineering
analysis with efficiencies above the
current standard are optimized to
operate at a PUL below 25 percent due
to the use of amorphous steel cores,
while certifying at the current standard
PUL. It is in the accompanying energy
conservation standards where details
and data related to the efficiency
standards of distribution transformers
can be fully evaluated under the EPCA
requirements that any new or amended
energy conservation standard be
designed to achieve the maximum
improvement in energy or water
28 Ibid.
E:\FR\FM\14SER2.SGM
14SER2
51245
Federal Register / Vol. 86, No. 175 / Tuesday, September 14, 2021 / Rules and Regulations
efficiency that is technologically
feasible and economically justified. (42
U.S.C. 6316(a); 42 U.S.C. 6295(o)(2)(A))
DOE is also permitting voluntary
representations of efficiency at
additional PULs so that manufacturers
can communicate to customers the
efficiency of their distribution
transformers at various service PULs, as
discussed in section III.D.3.
Additionally, voluntarily
representations at additional PULs may
be relied upon by voluntarily programs
such as ENERGY STAR®, which
publishes a buying guide 29 to assist
distribution transformer purchasers that
may save energy and cost in the context
of the purchasers’ specific PUL
distribution.
Finally, DOE notes that the observable
data and trends indicate that there are
ongoing changes in policies, consumer
demand, and data availability which are
beginning to have an impact on the
distribution transformer operations.
These changes present uncertainties
with regard to distribution transformer
loading, and DOE will continue to
evaluate changes in the market and in
operation that may require
consideration in future test procedure
evaluations.
3. Voluntary Representations of
Efficiency at Additional PULs
In the May 2019 NOPR, DOE
proposed amendments to the test
procedure to permit manufacturers to
make voluntary representations of
additional performance information of
distribution transformers when operated
under conditions other than those
required for compliance with the energy
conservation standards for distribution
transformers at 10 CFR 431.196. 84 FR
20704, 20714. DOE proposed the
provisions regarding voluntary
representations to help consumers make
better purchasing decisions based on
their specific installation conditions.
Specifically, DOE proposed in a new
section 7 of appendix A to specify that
manufacturers are permitted to
represent efficiency, no-load loss, or
load loss at additional PULs and/or
reference temperatures, as long as the
equipment is also represented in
accordance with DOE’s test procedure at
the mandatory (standard) PUL and
reference temperature. When making
voluntary representations, best practice
would be for the manufacturers also to
provide the PUL and reference
temperature corresponding to those
voluntary representations.
NEMA stated that the current test
procedure is already applicable to
alternative PULs. (NEMA, No. 30 at p.
4) Howard, CDA, and HVOLT
commented that voluntary
representations would be useful in
examining efficiencies at alternative
PULs. (Howard, No. 32 at p. 1; CDA, No.
29 at p. 3; CDA, No. 29 at p. 4; HVOLT,
No. 27 at p. 92–94)
As discussed, while the test
procedure accommodates testing at any
PUL, and correcting the results to reflect
any other specified PUL, DOE’s energy
conservation standards specify standard
PULs that must be used to represent the
energy efficiency of distribution
transformers. 10 CFR 431.196. EPCA
prohibits manufacturers from making
representations respecting the energy
consumption of covered equipment or
cost of energy consumed by such
equipment unless that equipment has
been tested in accordance with the
applicable DOE test procedure and such
representations fairly disclose the
results of that testing. (42 U.S.C.
6314(d)) Accordingly, there is benefit in
manufacturers being explicitly
permitted to make representations
respecting energy consumption at
alternative PULs and reference
temperatures that may better suit an
individual consumer’s demands.
For the reason expressed in the May
2019 NOPR and above, DOE is
establishing new section 7 of appendix
A, which explicitly provides that any
PUL and temperature values other than
those required for determining
compliance can be used for voluntary
representations when testing is
conducted in accordance with the
applicable DOE test procedure. Table
III.4 summarizes the applicable PUL and
temperature values.
TABLE III.4—SUMMARY OF VOLUNTARY REPRESENTATION
Mandatory certified values *
Reference
temperature
for loead loss
(°C)
PUL
(percent)
Metric
Voluntary representations
PUL
(percent)
Metric
Liquid Immersed ..........
Efficiency .....................
50
55
Efficiency, load loss,
no-load loss.
MVDT ...........................
LVDT ............................
.....................................
.....................................
50
35
75
75
Any .................
Reference
temperature
(°C)
Any.
* Efficiency must be determined at a reference temperature of 20 °C for no-load loss for all distribution transformers.
Some distribution transformers have
primary windings (‘‘primaries’’) and
secondary windings (‘‘secondaries’’)
that may each be reconfigured, for
example either in series or in parallel,
to accommodate multiple voltages.
Some configurations may be more
efficient than others.
Section 4.5.1(b) of appendix A
requires that for a transformer that has
a configuration of windings that allows
for more than one nominal rated
voltage, the load losses must be
determined either in the winding
configuration in which the highest
losses occur, or in each winding
configuration in which the transformer
can operate. Similarly, section 5.0 of
appendix A states that for a transformer
that has a configuration of windings that
allows for more than one nominal rated
voltage, its efficiency must be
determined either at the voltage at
which the highest losses occur, or at
each voltage at which the transformer is
rated to operate. Under either testing
and rating option (i.e., testing only the
highest loss configuration, or testing all
configurations), the winding
configuration that produces the highest
losses is tested and consequently must
comply with the applicable energy
conservation standard.
29 United States Environmental Protection
Agency. ENERGY STAR® Guide to Buying More
Energy Efficient Distribution Transformers. October
2017. Accessed July 7, 2021.
https://www.energystar.gov/sites/default/files/asset/
document/
Transformers%20Buyer%27s%20GuideFinal10-1617.pdf.
tkelley on DSK125TN23PROD with RULES2
E. Multiple Voltage Capability
VerDate Sep<11>2014
20:08 Sep 13, 2021
Jkt 253001
PO 00000
Frm 00017
Fmt 4701
Sfmt 4700
E:\FR\FM\14SER2.SGM
14SER2
tkelley on DSK125TN23PROD with RULES2
51246
Federal Register / Vol. 86, No. 175 / Tuesday, September 14, 2021 / Rules and Regulations
The relevant industry test standards,
IEEE C57.12.00–2015 and IEEE
C57.12.01–2020, direct distribution
transformers to be shipped with the
windings in series. Therefore, a
manufacturer physically testing for DOE
compliance may need to disassemble
the unit, reconfigure the windings to
test the configuration that produces the
highest losses, test the unit, then
reassemble the unit in its original
configuration for shipping, which
would add time and expense.
In the May 2019 NOPR, DOE did not
propose amending the requirement
related to transformers being tested in
the configuration that produces the
highest losses. 84 FR 20704, 20718. DOE
noted that it provides for certification
using an alternative efficiency
determination method (AEDM), which
is a mathematical model based on the
transformer design (10 CFR 429.47), and
that the availability of an AEDM
mitigates the potential cost associated
with having to physically test a unit in
a configuration other than in its ‘‘asshipped’’ configuration. Id.
Howard, NEMA, CDA and HVOLT
suggested that transformers be tested in
the ‘‘as-shipped’’ configuration, which
is typically with the windings in series.
(Howard, No 32 at p. 1; CDA, No. 29 at
p. 3; HVOLT, No. 27 at p. 92; NEMA,
No. 30 at p. 6) NEMA commented that
the requirement to test in the highest
losses configuration is confusing to
customers and adds undue burden on
manufacturers, whereas industry testing
standards have changed to test and ship
in highest voltage configurations.
(NEMA, No. 30 at p. 6) NEMA claims
the burden associated with requiring
testing of the configuration with the
highest loss is especially unnecessary
given that the overwhelming majority of
transformers are used in the highest
voltage configuration, with less than 5%
of transformers in applications other
than the ‘‘as-shipped’’ configuration.
(NEMA, No. 30 at p. 6) NEMA asserted
that while it can be hard to generalize
the losses associated with less efficient
winding configurations, given the
variability in application, the losses are
typically less than 1% of load losses,
and that it has never seen the difference
between configurations exceed 2% of
load losses. (NEMA, No. 30 at p. 4;
NEMA, No. 30 at p. 6) NEMA further
asserted that given the minimal
efficiency gains in testing in the highestloss and the relatively small percentage
of transformers operated in a
configuration other than ‘‘as-shipped’’,
the burden on manufacturers is not
justified. (NEMA, No. 30 at p. 6)
As stated in the May 2019 NOPR,
DOE recognizes that testing in the as-
VerDate Sep<11>2014
20:08 Sep 13, 2021
Jkt 253001
shipped condition may be less
burdensome for certain manufacturers,
but DOE also stated that it does not have
data to support NEMA’s claim that the
‘‘as-shipped’’ configuration would lead
to a maximum of 2 percent increase in
load losses. 84 FR 20704, 20718. NEMA
cited certain example distribution
transformers where the load loss
increase was 2 percent or less, however,
the data is only for a few select
distribution transformers and not
representative of the industry as a
whole. (NEMA, No. 30 at p. 7) In
interviews, several manufacturers
suggested that in certain extreme cases
the difference in efficiency could be
much higher than the 2 percent figure
cited by NEMA.
Further, even if DOE did have data
affirming the 2 percent figure NEMA
cited, it would be expected that such a
change to the test procedure would
require a corresponding change to the
energy conservation standards to
account for the change in measured load
loss values. A change to the energy
conservation standards would
necessitate certain manufacturers of
transformers with multiple windings to
re-test and re-certify their performance
to DOE.
As explained in the May 2019 NOPR,
as an alternative to physical testing,
DOE provides for certification using an
AEDM, which is a mathematical model
based on the transformer design. 10 CFR
429.47. The shipped configuration has
no bearing on the AEDM calculation,
and an AEDM can determine the
highest-loss configuration instantly.
DOE notes that most transformers are
currently certified using the AEDM and
the current burden is therefore less than
the commenters asserted for the
majority of manufacturers. In
interviews, manufacturers suggested
that this burden existed only when
verifying an AEDM. Further, many
distribution transformers are
reconfigured using a switch, which
minimizes effort required to change
winding configurations. NEMA
confirmed that there is no burden
associated with rewiring when utilizing
an AEDM and rather that the benefit to
changing to ‘‘as-shipped’’ testing is that
for higher-volume, single-phase pole
mount units manufacturers could
continually gauge the ‘‘as-shipped’’
performance against the AEDM. (NEMA,
Docket No. EERE–2017–BT–TP–0055–
0036 at p. 3) While there may be
benefits in continually gauging the ‘‘asshipped’’ performance against the
AEDM, DOE remains concerned about
the magnitude of the increase in load
losses for certain distribution
transformers.
PO 00000
Frm 00018
Fmt 4701
Sfmt 4700
As a result, DOE is not amending in
this final rule the current requirements
of section 4.5.1(b) of appendix A (for a
transformer that has a configuration of
windings that allows for more than one
nominal rated voltage, the load losses
must be determined either in the
winding configuration in which the
highest losses occur, or in each winding
configuration in which the transformer
can operate) and section 5.0 of appendix
A (for a transformer that has a
configuration of windings that allows
for more than one nominal rated
voltage, its efficiency must be
determined either at the voltage at
which the highest losses occur, or at
each voltage at which the transformer is
rated to operate).
F. Other Test Procedure Topics
In addition to the updates to the DOE
test procedure discussed in the
preceding sections, DOE also considered
whether the existing test procedure
would benefit from any further revisions
and/or reorganizing. Additional issues
are discussed in the following sections.
1. Per-Unit Load Specification
In the May 2019 NOPR, DOE
proposed to centralize the PUL
specifications, both for the certification
to energy conservation standards and for
use with a voluntary representation. 84
FR 20704, 20718–20719. Currently, the
PULs required for certification to energy
conservation standards are specified for
each class of distribution transformer at
10 CFR 431.196 and referenced
indirectly in multiple locations,
including 10 CFR 431.192 (within the
definition of reference temperature),
section 3.5(a) of appendix A, and
section 5.1 of appendix A. DOE
proposed to consolidate the PUL
specification into one location—a newly
proposed section 2.1 of appendix A.
Additionally, DOE proposed to provide
in the proposed section 2.1 of appendix
A that the PUL specification can be any
value for purposes of voluntary
representations. Id. DOE did not receive
any comments on these proposed
changes and is adopting them in this
final rule.
The consolidation enhances
readability of the test procedure and
more clearly communicates the PUL
requirements with respect to
certification to energy conservation
standards and voluntary
representations. The updates do not
change the standard PUL requirements
with respect to certification to energy
conservation standards. Instead, the
updates improve clarity with respect to
selection of PUL for voluntary
E:\FR\FM\14SER2.SGM
14SER2
Federal Register / Vol. 86, No. 175 / Tuesday, September 14, 2021 / Rules and Regulations
tkelley on DSK125TN23PROD with RULES2
representations versus certification to
energy conservation standards.
DOE also proposed editorial changes
to section 5.1 of appendix A to support
the consolidated approach to PUL
specification. 84 FR 20704, 20719.
Section 5.1 of appendix A provides
equations used to calculate load-losses
at any PUL. Section 5.1 of appendix A
used language that limited its
applicability to certification to energy
conservation standards only. For
example, it referenced the ‘‘specified
energy efficiency load level’’ (i.e., the
PUL required for certification to energy
conservation standards) specifically.
DOE proposed to generalize the
language in this section to reference the
PUL selected in the proposed section
2.1. Id.
DOE did not receive any comments
regarding these proposed editorial
changes and is adopting them in this
final rule.
2. Reference Temperature Specification
Similar to PUL, DOE proposed to
consolidate the reference temperature
specifications for certification to energy
conservation standards and for the
proposed voluntary representations. 84
FR 20704, 20719. The reference
temperature specifications for
certification to energy conservation
standards are defined at 10 CFR 431.192
(as the definition of ‘‘reference
temperature’’), and are referenced in
section 3.5(a) of appendix A and section
4.4.3.3 of appendix A. DOE proposed to
consolidate the reference temperature
specifications into one location—a
newly proposed section 2.2 of appendix
A. 84 FR 20704, 20719. Additionally,
DOE proposed to describe in the
proposed section 2.2 of appendix A that
the reference temperature specification
can be any value for purposes of
voluntary representations. Id. DOE did
not receive any comments on the
proposed changes and is adopting them
in this final rule.
Similar to PUL, this consolidation
will enhance readability of the test
procedure and more clearly
communicate DOE’s reference
temperature requirements with respect
to certification to energy conservation
standards or voluntary representations.
The updates do not change existing
reference temperature requirements
with respect to certification to energy
conservation standards. Instead, the
updates improve clarity with respect to
selection of reference temperature for
voluntary representations versus
certification to energy conservation
standards.
DOE also proposed editorial changes
to sections 3.5 and 4.4.3.3 of appendix
VerDate Sep<11>2014
20:08 Sep 13, 2021
Jkt 253001
A to support the consolidated approach
to reference temperature specification.
Section 3.5 of appendix A provided
reference temperatures for certification
to energy conservation standards. DOE
has consolidated reference temperature
specifications into one location (section
2.2); therefore, DOE has removed the
same specification in section 3.5 so that
the section is applicable to determine
voluntary representations.
Section 4.4.3.3 of appendix A
provides the specifications and
equations used for correcting no-load
loss to the reference temperature.
Specifically, the section provides an
option for no correction if the no-load
measurements were made between 10
°C and 30 °C (representing a ±10 °C
tolerance around the 20 °C reference
temperature). This tolerance is
applicable only for certification to
energy conservation standards. For
simplicity, DOE proposed no such
tolerance for voluntary representations
at additional reference temperatures, so
that all measured values would be
adjusted using the reference
temperature correction formula. 84 FR
20704, 20719. Finally, DOE proposed to
remove any reference to a reference
temperature of 20 °C so that the section
would be applicable to determine
voluntary representations. Id.
DOE did not receive any comments on
these proposed changes and is adopting
them in this final rule.
3. Measurement Location
DOE proposed to specify that load
and no-load loss measurements are
required to be taken only at the
transformer terminals. 84 FR 20704,
20719. In the May 2019 NOPR, DOE
proposed a definition for ‘‘terminal,’’ as
described in section III.C.2.b of this final
rule. DOE notes that section 5.4 of
IEEE.C57.12.90–2015 and section 5.6 of
IEEE C57.12.91–2020 specify terminalbased load-loss measurements. In
addition, section 8.2.4 of
IEEE.C57.12.90–2015 and section 8.2.5
of IEEE C57.12.91–2020 provide the
same for no-load loss measurement.
These documents reflect current
industry practices and manufacturers
are already measuring losses at the
transformer terminals. Therefore, DOE
proposed to specify in section 4.3(c) of
appendix A that both load loss and noload loss measurements must be made
from terminal to terminal. 84 FR 20704,
20719.
DOE received no comments in
response to this proposal and is
adopting it in this final rule.
PO 00000
Frm 00019
Fmt 4701
Sfmt 4700
51247
4. Specification for Stabilization of
Current and Voltage
Section 3.3.2 and 3.3.1 of appendix A
describe a voltmeter-ammeter method
and resistance bridge methods,
respectively, for measuring resistance.
Both methods require measurements to
be stable before determining the
resistance of the transformer winding
being measured. Specifically, the
voltmeter-ammeter method in section
3.3.2(b) of appendix A requires that
current and voltage readings be stable
before taking simultaneous readings of
current and voltage to determine
winding resistance. For the resistance
bridge methods, section 3.3.1 of
appendix A requires the bridge to be
balanced (i.e., no voltage across it or
current through it) before determining
winding resistance. Both methods allow
for a resistor to reduce the time constant
of the circuit, but do not explicitly
specify how to determine when
measurements are stable. DOE notes that
IEEE C57.12.90–2015, IEEE C57.12.91–
2020, IEEE C57.12.00–2015, and IEEE
C57.12.01–2020 do not specify how to
determine that stabilization is reached.
Section 3.4.2 of appendix A provides
related instruction for improving
measurement accuracy of resistance by
reducing the transformer’s time
constant. However, section 3.4.2 also
does not explicitly provide for the
period of time (such as a certain
multiple of the time constant) necessary
to achieve stability. In the May 2019
NOPR, DOE requested comment on how
industry currently determines that
measurements have stabilized before
determining winding resistance using
both voltmeter-ammeter method and
resistance bridge methods. 84 FR 20704,
20719.
NEMA commented that testing is
typically done with a computer/
electronic automatic test system where
the feature is provided. NEMA stated
that its members have not used a
resistance bridge method in 20 years.
(NEMA, No. 30 at p. 4) HVOLT and
CDA commented that both the
resistance bridge and voltmeterammeter methods should be accurate as
long as four-time constants have passed.
(HVOLT, No. 27 at p. 93; CDA, No. 29
at p. 3)
Commenters have not suggested that
there is an issue with the accuracy of
measurements associated with
achieving sufficient stability and did not
suggest that DOE needed to explicitly
provide for the period of time necessary
to achieve stability. Therefore, DOE has
not adopted any amendments related to
the period of time to achieve stability.
E:\FR\FM\14SER2.SGM
14SER2
51248
Federal Register / Vol. 86, No. 175 / Tuesday, September 14, 2021 / Rules and Regulations
5. Ambient Temperature Tolerances
In response to the September 2017
RFI, NEMA recommended that DOE
increase the ambient temperature
tolerances for testing dry-type
transformers, stating that testing may
otherwise be burdensome in laboratories
that are not climate controlled, and that
a mathematical correction factor could
be developed as an alternative to the
temperature limits. (NEMA, Docket No.
EERE–2017–BT–0055–0014 at p. 2)
In the May 2019 NOPR, DOE
explained that while widening the
tolerances of temperatures (or other
measured parameters) may reduce
testing cost, it may impact the
reproducibility and repeatability of the
test result. 84 FR 20704, 20719–20720.
Further, NEMA acknowledged that
manufacturers are not having difficulty
meeting the temperature requirement.
(NEMA, Docket No. EERE–2017–BT–
0055–0014 at p. 8)
DOE does not have data regarding
typical ranges of laboratory ambient
temperature and, as a result, cannot be
certain that reduction in temperature
tolerance would not impact
reproducibility, repeatability, and
accuracy and cause future test results to
become incomparable to past data. For
these reasons, DOE did not propose
amendments to the laboratory ambient
temperature and transformer internal
temperature requirements in the May
2019 NOPR. 84 FR 20704, 20720.
Comments received on this issue
supported maintaining the current
ambient temperature tolerances.
(Howard, No. 31 at p. 1; NEMA, No. 30
at p. 4; CDA, No. 29 at p. 3; HVOLT, No.
27 at p. 93) For the reasons discussed
in the May 2019 NOPR and in the
preceding paragraph, DOE is
maintaining the ambient temperature
requirements in appendix A.
tkelley on DSK125TN23PROD with RULES2
6. Harmonic Current
Harmonic current refers to electrical
power at alternating current frequencies
greater than the fundamental frequency.
Distribution transformers in service are
commonly subject to (and must tolerate)
harmonic current of a degree that varies
by application. Sections 4.4.1(a) and
4.4.3.2(a) of appendix A direct use of a
sinusoidal waveform for evaluating
efficiency in distribution transformers.
DOE recognizes that transformers in
service are subject to a variety of
harmonic conditions, and that the test
procedure must provide a common basis
for comparison. Currently, the test
procedure states that transformers
designed for harmonic currents must be
tested with a sinusoidal waveform (i.e.,
free of harmonic current), but does not
VerDate Sep<11>2014
20:08 Sep 13, 2021
Jkt 253001
do so for all other varieties of
transformers. However, the intent of the
test procedure is for all transformers to
be tested with a sinusoidal waveform, as
is implicit in section 4.4.1(a) of
appendix A. To clarify this test setup
requirement, DOE proposed to modify
section 4.1 of appendix A to read ‘‘. . .
Test all distribution transformers using
a sinusoidal waveform (k=1).’’ 84 FR
20704, 20720 This is consistent with
industry practice and manufacturers are
already testing all distribution
transformers using a sinusoidal
waveform. Id.
DOE received several comments in
support of this clarification and none in
opposition. (Howard, No. 32 at p. 2;
NEMA, No. 30 at p. 4; CDA, No. 29 at
p. 3; HVOLT, No. 27 at p. 93) For the
reasons discussed in the May 2019
NOPR and in the preceding paragraph,
DOE is adopting the clarification
regarding use of a sinusoidal waveform
as proposed.
7. Other Editorial Revisions
In the May 2019 NOPR, DOE
proposed the following editorial
updates to improve the readability of
the test procedure and provide
additional detail: (i) Revising ‘‘shall’’
(and a single instance of ‘‘should’’ in the
temperature condition requirements at
section 3.2.2(b)(3)) to ‘‘must’’
throughout appendix A, (ii) clarifying
the instructional language for recording
the winding temperature for dry-type
transformers (section 3.2.2 of appendix
A), (iii) separating certain sentences into
enumerated clauses (section 3.2.2(a) of
appendix A),30 (iv) identifying the
corresponding resistance measurement
method sections (section 3.3 of
appendix A), (v) replacing a reference to
‘‘uniform test method’’ with ‘‘this
appendix’’ (section 3.3 of appendix A),
(vi) removing reference to guidelines
under section 3.4.1, Required actions, of
appendix A to clarify that section
establishes requirements, (vii)
specifying the maximum amount of time
for the temperature of the transformer
windings to stabilize (section 3.2.2(b)(4)
of appendix A 31), (viii) removing
references to the test procedure in 10
CFR 431.196, and (ix) replacing any
reference to accuracy requirements in
‘‘section 2.0’’ and/or ‘‘Table 2.0’’ to
‘‘section 2.3’’ and/or ‘‘Table 2.3,’’
accordingly. 84 FR 20704, 20720.
Section 3.2.2 of appendix A requires
that, for testing of both ventilated and
30 Under the changes adopted in this document,
section 3.2.2(a) of appendix A is split into section
3.2.2(a) and section 3.2.2(b).
31 Under the changes adopted in this document,
this section is redesignated as section 3.2.2(c)(4) of
appendix A.
PO 00000
Frm 00020
Fmt 4701
Sfmt 4700
sealed units, the ambient temperature of
the test area may be used to estimate the
winding temperature (rather than direct
measurement of the winding
temperature), provided a number of
conditions are met, including the
condition that neither voltage nor
current has been applied to the unit
under test for 24 hours (provided in
section 3.2.2(b)(4) of appendix A). The
same section also allows for the time
period of the initial 24 hours to be
increased to up to a maximum of an
additional 24 hours, so as to allow the
temperature of the transformer windings
to stabilize at the level of the ambient
temperature. Based on this requirement,
the total amount of time allowed would
be a maximum of 48 hours. As such, in
the May 2019 NOPR, DOE proposed to
specify explicitly that, for section
3.2.2(b)(4) of appendix A, the total
maximum amount of time allowed is 48
hours. Id.
DOE also proposed conforming
amendments to the energy conservation
standard provisions. The provisions in
10 CFR 431.196 establishes energy
conservation standards for certain
distribution transformers. Id.
Immediately following each table of
standards, a note specifies the
applicable standard PUL and DOE test
procedure. For example, in 10 CFR
431.196(a) the note reads, ‘‘Note: All
efficiency values are at 35 percent of
nameplate-rated load, determined
according to the DOE Test Method for
Measuring the Energy Consumption of
Distribution Transformers under
appendix A to subpart K of 10 CFR part
431.’’ Because 10 CFR 431.193 already
requires that testing be in accordance
with appendix A, DOE proposes to
remove the references to the test
procedure in 10 CFR 431.196. DOE
proposes to maintain the portion of the
note identifying the PUL corresponding
to the efficiency values, for continuity
and clarity. Id.
As discussed in sections III.F.1 and
III.F.2 of this final rule, DOE is
clarifying the PUL and reference
temperature specifications for
certification to energy conservation
standards, and providing PUL and
reference temperature specifications for
voluntary representations, with a new
section 2.1 for PUL requirements and
section 2.2 for reference temperature
requirements in appendix A.
Accordingly, DOE proposed that the
accuracy requirements previously
provided in section 2.0 be moved to
section 2.3 in appendix A. In addition,
DOE proposed to re-number Table 2.1,
Test System Accuracy Requirements for
Each Measured Quantity, to Table 2.3.
Lastly, DOE proposed to update cross-
E:\FR\FM\14SER2.SGM
14SER2
Federal Register / Vol. 86, No. 175 / Tuesday, September 14, 2021 / Rules and Regulations
tkelley on DSK125TN23PROD with RULES2
references in appendix A to the
accuracy requirements in section 2.0
and/or Table 2.1, to section 2.3 and/or
Table 2.3. The cross-references occur in
sections 3.1(b), 3.3.3, 3.4.2(a), 4.3(a), 6.0,
and 6.2 of appendix A.
DOE did not receive any comment in
opposition to these edits and is adopting
them in the test procedure.
NEMA noted certain errors in the
equation references in section 4 of
appendix A. (NEMA, No. 30 at p. 5)
Specifically, NEMA stated that the load
loss power (Plc1) appears with subscripts
‘‘LCL’’, ‘‘LCI’’, and ‘‘LC1’’ (capital letters
used for clarity, but lower case used in
the text). Id. DOE has reviewed the
subscripts in section 4 of appendix A
and corrected each instance to ‘‘LC1’’
(capitalized here for clarity) where
necessary.
NEMA also noted that there is
potential confusion regarding which
reference temperature should be used in
section 4.5.3.3 of appendix A. NEMA
suggested to clarify the text as follows:
‘‘When the measurement of load loss is
made at a temperature Tim that is
different from the reference
temperature, use the procedure
summarized in the equations 4–6 to 4–
10 to correct the measured load loss to
the reference temperature (as defined in
3.5 (a)).’’ (NEMA, No. 30 at p. 5–6) This
final rule includes a new section,
section 2.2 of appendix A, to specify
reference temperature in a centralized
location, as described in section III.F.2
of this document. In view of the new
requirement, NEMA’s suggested edits to
specify reference temperature in section
4.5.3.3 are redundant.
PG&E commented in response to the
May 2019 NOPR that in order to
properly comment, it would like a
before and after document of proposed
changes to the CFR. (PG&E, No. 33 at p.
1) The May 2019 NOPR includes a
synopsis table of the proposed changes,
including a side-by-side comparison of
the current DOE TP language, the
proposed test procedure language, and
attribution of the changes. 84 FR 20704,
20706. Further, DOE published all
proposed regulatory text in the May
2019 NOPR which could be juxtaposed
with the current CFR in order to
perform the comparison PG&E
describes. 84 FR 20704, 20727–20730.
G. Effective and Compliance Dates
The effective date for the adopted test
procedure amendment is 30 days after
publication of this final rule in the
Federal Register. EPCA prescribes that
all representations of energy efficiency
and energy use, including those made
on marketing materials and product
labels, must be made in accordance with
VerDate Sep<11>2014
20:08 Sep 13, 2021
Jkt 253001
an amended test procedure, beginning
180 days after publication of the final
rule in the Federal Register. (42 U.S.C.
6293(c)(2); 42 U.S.C. 6314(d)(1)) EPCA
provides an allowance for individual
manufacturers to petition DOE for an
extension of the 180-day period if the
manufacturer may experience undue
hardship in meeting the deadline. (42
U.S.C. 6293(c)(3); 42 U.S.C. 6314(d)(2))
To receive such an extension, petitions
must be filed with DOE no later than 60
days before the end of the 180-day
period and must detail how the
manufacturer will experience undue
hardship. (Id.)
H. Test Procedure Costs
In this final rule, DOE is amending
the existing test procedure for
distribution transformers by revising
certain definitions, incorporating new
definitions, incorporating revisions
based on the latest versions of the IEEE
industry testing standards, including
provisions to allow manufacturers to
use the DOE test procedure to make
voluntary representations at additional
PULs and/or reference temperatures,
and reorganizing content among
relevant sections of the CFR to improve
readability. The adopted amendments
primarily provide updates and
supplemental details for how to conduct
the test procedure and do not add
complexity to test conditions/setup or
add test steps. In accordance with
EPCA, DOE has determined that these
adopted amendments will not be
unduly burdensome for manufacturers
to conduct. Further, DOE has
determined that the adopted test
procedure amendments will not impact
testing costs already experienced by
manufacturers. DOE estimated, based on
a test quote from a laboratory, that the
cost for testing distribution transformers
using the existing test procedure is
approximately $400 per unit tested and
that this figure will not change in
response to the adopted test procedure
amendments. In summary, the adopted
test procedure amendments reflect and
codify current industry practice.
As previously described in the May
2019 NOPR, the adopted amendments
will not impact the scope of the test
procedure. The adopted amendments
will not require the testing of
distribution transformers not already
subject to the test procedure at 10 CFR
431.193 (i.e., the adopted amendments
will not require manufacturers to test
autotransformers, drive (isolation)
transformers, grounding transformers,
machine-tool (control) transformers,
nonventilated transformers, rectifier
transformers, regulating transformers,
sealed transformer; special-impedance
PO 00000
Frm 00021
Fmt 4701
Sfmt 4700
51249
transformer; testing transformer;
transformer with tap range of 20 percent
or more; uninterruptible power supply
transformer; or welding transformer,
which are presently not subject to
testing). The adopted amendments will
not alter the measured energy efficiency
or energy use of the distribution
transformers. Manufacturers will be able
to rely on data generated under the
current test procedure. Further, the
adopted amendments will not require
the purchase of additional equipment
for testing.
In the May 2019 NOPR, DOE
described why the proposed test
procedure amendments would not add
costs to manufacturers. In response,
manufacturers commented stating the
proposed testing should not increase
testing costs for any manufacturers.
(Howard, No. 32 at p. 2; CDA, No. 29
at p. 3–4; HVOLT, No. 27 at p. 91–93)
NEMA commented that it does not
anticipate any negative impact or
increased costs associated with any of
the proposed changes but stressed that
DOE continue to allow manufacturers to
certify distribution transformers using
an AEDM as is allowed at 10 CFR
429.70(d) in order to minimize testing
costs. (NEMA, No. 30 at p. 4) DOE notes
that it has not proposed or adopted any
changes to 10 CFR 429.70(d), and
manufacturers are permitted to use an
AEDM for means of certifying
distribution transformer efficiency to
DOE.
IV. Procedural Issues and Regulatory
Review
A. Review Under Executive Order 12866
The Office of Management and Budget
(‘‘OMB’’) has determined this test
procedure rulemaking does not
constitute a ‘‘significant regulatory
action’’ under section 3(f) of Executive
Order (‘‘E.O.’’) 12866, Regulatory
Planning and Review, 58 FR 51735 (Oct.
4, 1993). Accordingly, this action was
not subject to review under the
Executive order by the Office of
Information and Regulatory Affairs
(‘‘OIRA’’) in OMB.
B. Review Under the Regulatory
Flexibility Act
The Regulatory Flexibility Act (5
U.S.C. 601 et seq.) requires preparation
of a final regulatory flexibility analysis
(‘‘FRFA’’) for any final rule where the
agency was first required by law to
publish a proposed rule for public
comment, unless the agency certifies
that the rule, if promulgated, will not
have a significant economic impact on
a substantial number of small entities.
As required by Executive Order 13272,
E:\FR\FM\14SER2.SGM
14SER2
51250
Federal Register / Vol. 86, No. 175 / Tuesday, September 14, 2021 / Rules and Regulations
tkelley on DSK125TN23PROD with RULES2
‘‘Proper Consideration of Small Entities
in Agency Rulemaking,’’ 67 FR 53461
(August 16, 2002), DOE published
procedures and policies on February 19,
2003 to ensure that the potential
impacts of its rules on small entities are
properly considered during the DOE
rulemaking process. 68 FR 7990. DOE
has made its procedures and policies
available on the Office of the General
Counsel’s website: https://energy.gov/
gc/office-general-counsel.
As stated, the amendments adopted in
this final rule revise certain definitions,
incorporate new definitions, incorporate
revisions based on the latest versions of
the IEEE industry testing standards,
include provisions to allow
manufacturers to use the DOE test
procedure to make voluntary
representations at additional PULs and/
or reference temperatures, and
reorganize content among relevant
sections of the CFR to improve
readability. DOE has determined that
the adopted test procedure amendments
would not impact testing costs already
experienced by manufacturers. NEMA,
CDA, and HVOLT commented that they
do not anticipate any undue burden on
small businesses or small
manufacturers. (NEMA, No. 30 at p. 5;
CDA, No. 29 at p. 4; HVOLT, No. 27 at
p. 94)
Therefore, DOE concludes that the
cost effects accruing from the final rule
would not have a ‘‘significant economic
impact on a substantial number of small
entities,’’ and that the preparation of a
FRFA is not warranted. DOE has
submitted a certification and supporting
statement of factual basis to the Chief
Counsel for Advocacy of the Small
Business Administration for review
under 5 U.S.C. 605(b).
C. Review Under the Paperwork
Reduction Act of 1995
Manufacturers of distribution
transformers must certify to DOE that
their products comply with any
applicable energy conservation
standards. To certify compliance,
manufacturers must first obtain test data
for their products according to the DOE
test procedure, including any
amendments adopted for that test
procedure. DOE has established
regulations for the certification and
recordkeeping requirements for all
covered consumer products and
commercial equipment, including
distribution transformers. (See generally
10 CFR part 429.) The collection-ofinformation requirement for the
certification and recordkeeping is
subject to review and approval by OMB
under the Paperwork Reduction Act
(PRA). This requirement has been
VerDate Sep<11>2014
20:08 Sep 13, 2021
Jkt 253001
approved by OMB under OMB control
number 1910–1400. Public reporting
burden for the certification is estimated
to average 35 hours per response,
including the time for reviewing
instructions, searching existing data
sources, gathering and maintaining the
data needed, and completing and
reviewing the collection of information.
The amendments adopted in this final
rule do not impact the certification and
reporting requirements for distribution
transformers.
Notwithstanding any other provision
of the law, no person is required to
respond to, nor shall any person be
subject to a penalty for failure to comply
with, a collection of information subject
to the requirements of the PRA, unless
that collection of information displays a
currently valid OMB Control Number.
D. Review Under the National
Environmental Policy Act of 1969
Pursuant to the National
Environmental Policy Act of 1969
(‘‘NEPA’’), DOE has analyzed this action
in accordance with NEPA and DOE’s
NEPA implementing regulations (10
CFR part 1021). DOE has determined
that this rule qualifies for categorical
exclusion under 10 CFR part 1021,
subpart D, appendix A5, because it is an
interpretive rulemaking that does not
change the environmental effect of the
rule and meets the requirements for
application of a CX. See 10 CFR
1021.410. Therefore, DOE has
determined that promulgation of this
rule is not a major Federal action
significantly affecting the quality of the
human environment within the meaning
of NEPA and does not require an EA or
EIS.
E. Review Under Executive Order 13132
Executive Order 13132, ‘‘Federalism,’’
64 FR 43255 (August 4, 1999), imposes
certain requirements on agencies
formulating and implementing policies
or regulations that preempt State law or
that have federalism implications. The
Executive order requires agencies to
examine the constitutional and statutory
authority supporting any action that
would limit the policymaking discretion
of the States and to carefully assess the
necessity for such actions. The
Executive order also requires agencies to
have an accountable process to ensure
meaningful and timely input by State
and local officials in the development of
regulatory policies that have federalism
implications. On March 14, 2000, DOE
published a statement of policy
describing the intergovernmental
consultation process it will follow in the
development of such regulations. 65 FR
13735. DOE examined this final rule
PO 00000
Frm 00022
Fmt 4701
Sfmt 4700
and determined that it will not have a
substantial direct effect on the States, on
the relationship between the National
Government and the States, or on the
distribution of power and
responsibilities among the various
levels of government. EPCA governs and
prescribes Federal preemption of State
regulations as to energy conservation for
the products that are the subject of this
final rule. States can petition DOE for
exemption from such preemption to the
extent, and based on criteria, set forth in
EPCA. (42 U.S.C. 6297(d)) No further
action is required by Executive Order
13132.
F. Review Under Executive Order 12988
Regarding the review of existing
regulations and the promulgation of
new regulations, section 3(a) of
Executive Order 12988, ‘‘Civil Justice
Reform,’’ 61 FR 4729 (Feb. 7, 1996),
imposes on Federal agencies the general
duty to adhere to the following
requirements: (1) Eliminate drafting
errors and ambiguity; (2) write
regulations to minimize litigation; (3)
provide a clear legal standard for
affected conduct rather than a general
standard; and (4) promote simplification
and burden reduction. Section 3(b) of
Executive Order 12988 specifically
requires that executive agencies make
every reasonable effort to ensure that the
regulation (1) clearly specifies the
preemptive effect, if any; (2) clearly
specifies any effect on existing Federal
law or regulation; (3) provides a clear
legal standard for affected conduct
while promoting simplification and
burden reduction; (4) specifies the
retroactive effect, if any; (5) adequately
defines key terms; and (6) addresses
other important issues affecting clarity
and general draftsmanship under any
guidelines issued by the Attorney
General. Section 3(c) of Executive Order
12988 requires executive agencies to
review regulations in light of applicable
standards in sections 3(a) and 3(b) to
determine whether they are met, or it is
unreasonable to meet one or more of
them. DOE has completed the required
review and determined that, to the
extent permitted by law, this final rule
meets the relevant standards of
Executive Order 12988.
G. Review Under the Unfunded
Mandates Reform Act of 1995
Title II of the Unfunded Mandates
Reform Act of 1995 (‘‘UMRA’’) requires
each Federal agency to assess the effects
of Federal regulatory actions on State,
local, and Tribal governments, and the
private sector. Public Law 104–4, sec.
201 (codified at 2 U.S.C. 1531). For a
regulatory action resulting in a rule that
E:\FR\FM\14SER2.SGM
14SER2
Federal Register / Vol. 86, No. 175 / Tuesday, September 14, 2021 / Rules and Regulations
may cause the expenditure by State,
local, and Tribal governments, in the
aggregate, or by the private sector of
$100 million or more in any one year
(adjusted annually for inflation), section
202 of UMRA requires a Federal agency
to publish a written statement that
estimates the resulting costs, benefits,
and other effects on the national
economy. (2 U.S.C. 1532(a), (b)) The
UMRA also requires a Federal agency to
develop an effective process to permit
timely input by elected officers of State,
local, and Tribal governments on a
proposed ‘‘significant intergovernmental
mandate,’’ and requires an agency plan
for giving notice and opportunity for
timely input to potentially affected
small governments before establishing
any requirements that might
significantly or uniquely affect small
governments. On March 18, 1997, DOE
published a statement of policy on its
process for intergovernmental
consultation under UMRA. 62 FR
12820; also available at https://
energy.gov/gc/office-general-counsel.
DOE examined this final rule according
to UMRA and its statement of policy
and determined that the rule contains
neither an intergovernmental mandate,
nor a mandate that may result in the
expenditure of $100 million or more in
any year, so these requirements do not
apply.
H. Review Under the Treasury and
General Government Appropriations
Act, 1999
Section 654 of the Treasury and
General Government Appropriations
Act, 1999 (Pub. L. 105–277) requires
Federal agencies to issue a Family
Policymaking Assessment for any rule
that may affect family well-being. This
final rule will not have any impact on
the autonomy or integrity of the family
as an institution. Accordingly, DOE has
concluded that it is not necessary to
prepare a Family Policymaking
Assessment.
tkelley on DSK125TN23PROD with RULES2
I. Review Under Executive Order 12630
DOE has determined, under Executive
Order 12630, ‘‘Governmental Actions
and Interference with Constitutionally
Protected Property Rights’’ 53 FR 8859
(March 18, 1988), that this regulation
will not result in any takings that might
require compensation under the Fifth
Amendment to the U.S. Constitution.
J. Review Under Treasury and General
Government Appropriations Act, 2001
Section 515 of the Treasury and
General Government Appropriations
VerDate Sep<11>2014
20:08 Sep 13, 2021
Jkt 253001
Act, 2001 (44 U.S.C. 3516 note) provides
for agencies to review most
disseminations of information to the
public under guidelines established by
each agency pursuant to general
guidelines issued by OMB. OMB’s
guidelines were published at 67 FR
8452 (Feb. 22, 2002), and DOE’s
guidelines were published at 67 FR
62446 (Oct. 7, 2002). Pursuant to OMB
Memorandum M–19–15, Improving
Implementation of the Information
Quality Act (April 24, 2019), DOE
published updated guidelines which are
available at www.energy.gov/sites/prod/
files/2019/12/f70/DOE%20
Final%20Updated%20
IQA%20Guidelines%20
Dec%202019.pdf. DOE has reviewed
this final rule under the OMB and DOE
guidelines and has concluded that it is
consistent with applicable policies in
those guidelines.
K. Review Under Executive Order 13211
Executive Order 13211, ‘‘Actions
Concerning Regulations That
Significantly Affect Energy Supply,
Distribution, or Use,’’ 66 FR 28355 (May
22, 2001), requires Federal agencies to
prepare and submit to OMB, a
Statement of Energy Effects for any
significant energy action. A ‘‘significant
energy action’’ is defined as any action
by an agency that promulgated or is
expected to lead to promulgation of a
final rule, and that (1) is a significant
regulatory action under Executive Order
12866, or any successor order; and (2)
is likely to have a significant adverse
effect on the supply, distribution, or use
of energy; or (3) is designated by the
Administrator of OIRA as a significant
energy action. For any significant energy
action, the agency must give a detailed
statement of any adverse effects on
energy supply, distribution, or use if the
regulation is implemented, and of
reasonable alternatives to the action and
their expected benefits on energy
supply, distribution, and use.
This regulatory action is not a
significant regulatory action under
Executive Order 12866. Moreover, it
would not have a significant adverse
effect on the supply, distribution, or use
of energy, nor has it been designated as
a significant energy action by the
Administrator of OIRA. Therefore, it is
not a significant energy action, and,
accordingly, DOE has not prepared a
Statement of Energy Effects.
PO 00000
Frm 00023
Fmt 4701
Sfmt 4700
51251
L. Review Under Section 32 of the
Federal Energy Administration Act of
1974
Under section 301 of the Department
of Energy Organization Act (Pub. L. 95–
91; 42 U.S.C. 7101), DOE must comply
with section 32 of the Federal Energy
Administration Act of 1974, as amended
by the Federal Energy Administration
Authorization Act of 1977. (15 U.S.C.
788; ‘‘FEAA’’) Section 32 essentially
provides in relevant part that, where a
proposed rule authorizes or requires use
of commercial standards, the notice of
proposed rulemaking must inform the
public of the use and background of
such standards. In addition, section
32(c) requires DOE to consult with the
Attorney General and the Chairman of
the Federal Trade Commission (‘‘FTC’’)
concerning the impact of the
commercial or industry testing
standards on competition.
The modifications to the test
procedure for distribution transformers
adopted in this final rule do not
incorporate testing methods contained
in commercial standards. Therefore, the
requirements of section 32(b) of the
FEAA do not apply.
M. Congressional Notification
As required by 5 U.S.C. 801, DOE will
report to Congress on the promulgation
of this rule before its effective date. The
report will state that it has been
determined that the rule is not a ‘‘major
rule’’ as defined by 5 U.S.C. 804(2).
V. Approval of the Office of the
Secretary
The Secretary of Energy has approved
publication of this final rule.
List of Subjects in 10 CFR Part 431
Administrative practice and
procedure, Confidential business
information, Energy conservation test
procedures, and Reporting and
recordkeeping requirements.
Signing Authority
This document of the Department of
Energy was signed on September 2,
2021, by Kelly Speakes-Backman,
Principal Deputy Assistant Secretary
and Acting Assistant Secretary for
Energy Efficiency and Renewable
Energy, pursuant to delegated authority
from the Secretary of Energy. That
document with the original signature
and date is maintained by DOE. For
administrative purposes only, and in
compliance with requirements of the
E:\FR\FM\14SER2.SGM
14SER2
51252
Federal Register / Vol. 86, No. 175 / Tuesday, September 14, 2021 / Rules and Regulations
Office of the Federal Register, the
undersigned DOE Federal Register
Liaison Officer has been authorized to
sign and submit the document in
electronic format for publication, as an
official document of the Department of
Energy. This administrative process in
no way alters the legal effect of this
document upon publication in the
Federal Register.
Signed in Washington, DC, on September
2, 2021.
Treena V. Garrett,
Federal Register Liaison Officer, U.S.
Department of Energy.
For the reasons stated in the
preamble, DOE amends part 431 of
chapter II of title 10, Code of Federal
Regulations as set forth below:
PART 431—ENERGY EFFICIENCY
PROGRAM FOR CERTAIN
COMMERCIAL AND INDUSTRIAL
EQUIPMENT
1. The authority citation for part 431
continues to read as follows:
■
Authority: 42 U.S.C. 6291–6317; 28 U.S.C.
2461 note.
2. Section 431.192 is amended by:
a. Adding in alphabetical order the
definition for Auxiliary device;
■ b. Revising the definition of Lowvoltage dry-type distribution
transformer;
■ c. Adding in alphabetical order the
definition for Per-unit load;
■ d. Revising the definition of Reference
temperature; and
■ e. Adding in alphabetical order the
definition for Terminal.
The additions and revisions read as
follows:
■
■
§ 431.192
Definitions.
tkelley on DSK125TN23PROD with RULES2
*
*
*
*
*
Auxiliary device means a localized
component of a distribution transformer
that is a circuit breaker, switch, fuse, or
surge/lightning arrester.
*
*
*
*
*
Low-voltage dry-type distribution
transformer means a distribution
transformer that has an input voltage of
600 volts or less and has the core and
coil assembly immersed in a gaseous or
dry-compound insulating medium.
*
*
*
*
*
Per-unit load means the fraction of
rated load.
*
*
*
*
*
Reference temperature means the
temperature at which the transformer
losses are determined, and to which
such losses are corrected if testing is
done at a different point. (Reference
temperature values are specified in the
VerDate Sep<11>2014
20:08 Sep 13, 2021
Jkt 253001
test method in appendix A to this
subpart.)
*
*
*
*
*
Terminal means a conducting element
of a distribution transformer providing
electrical connection to an external
conductor that is not part of the
transformer.
*
*
*
*
*
■ 3. Section 431.193 is revised to read
as follows:
§ 431.193 Test procedure for measuring
energy consumption of distribution
transformers.
The test procedure for measuring the
energy efficiency of distribution
transformers for purposes of EPCA is
specified in appendix A to this subpart.
The test procedure specified in
appendix A to this subpart applies only
to distribution transformers subject to
energy conservation standards at
§ 431.196.
■ 4. Section 431.196 is amended by
revising the Notes in paragraphs (a)(1)
and (2), (b)(1) and (2), and (c)(1) and (2)
to read as follows:
§ 431.196 Energy conservation standards
and their effective dates.
(a) * * *
(1) * * *
Note 1 to paragraph (a)(1): All efficiency
values are at 35 percent per-unit load.
(2) * * *
Note 2 to paragraph (a)(2): All efficiency
values are at 35 percent per-unit load.
(b) * * *
(1) * * *
Note 3 to paragraph (b)(1): All efficiency
values are at 50 percent per-unit load.
(2) * * *
Note 4 to paragraph (b)(2): All efficiency
values are at 50 percent per-unit load.
(c) * * *
(1) * * *
Note 5 to paragraph (c)(1): All efficiency
values are at 50 percent per-unit load.
f. Revising section 3.3;
■ g. Revising paragraph (a) introductory
text and paragraph (b) in section 3.3.2;
■ h. Revising section 3.3.3;
■ i. Revising the introductory text and
adding paragraphs (f), (g), (h), and (i) in
section 3.4.1;
■ j. Revising paragraph (a) in section
3.4.2;
■ k. Revising paragraph (a) in section
3.5;
■ l. Revising section 4.1;
■ m. Revising paragraph (a) and adding
paragraph (c) in section 4.3;
■ n. Revising section 4.4.3.3;
■ o. Revising paragraph (c) of section
4.5.3.2;
■ p. Revising section 5.1;
■ q. Revising section 6.0;
■ r. Revising section 6.1;
■ s. Revising paragraph (a) in section
6.2; and
■ t. Adding section 7.0.
The additions and revisions read as
follows:
■
Appendix A to Subpart K of Part 431—
Uniform Test Method for Measuring the
Energy Consumption of Distribution
Transformers
*
*
*
*
*
2.0 Per-Unit Load, Reference Temperature,
and Accuracy Requirements
2.1 Per-Unit Load
In conducting the test procedure in this
appendix for the purpose of:
(a) Certification to an energy conservation
standard, the applicable per-unit load in
Table 2.1 must be used; or
(b) Making voluntary representations as
provided in section 7.0 at an additional perunit load, select the per-unit load of interest.
TABLE 2.1—PER-UNIT LOAD FOR CERTIFICATION TO ENERGY CONSERVATION STANDARDS
(2) * * *
Note 6 to paragraph (c)(2): All efficiency
values are at 50 percent per-unit load.
Distribution transformer category
*
Liquid-immersed .........................
Medium-voltage dry-type ............
Low-voltage dry-type ..................
*
*
*
*
■ 5. Appendix A to subpart K of part
431 is amended by:
■ a. In section 2.0:
■ i. Revising the section heading;
■ ii. Removing paragraphs (a) and (b);
and
■ iii. Adding sections 2.1, 2.2, and 2.3;
■ b. Adding paragraph (c) to section 3.1;
■ c. Revising section 3.2.1.1;
■ d. Revising paragraph (b) in section
3.2.1.2;
■ e. Revising section 3.2.2;
PO 00000
Frm 00024
Fmt 4701
Sfmt 4700
Per-unit
load
(percent)
50
50
35
2.2 Reference Temperature
In conducting the test procedure in this
appendix for the purpose of:
(a) Certification to an energy conservation
standard, the applicable reference
temperature in Table 2.2 must be used; or
(b) Making voluntary representations as
provided in section 7.0 at an additional
reference temperature, select the reference
temperature of interest.
E:\FR\FM\14SER2.SGM
14SER2
Federal Register / Vol. 86, No. 175 / Tuesday, September 14, 2021 / Rules and Regulations
TABLE 2.2—REFERENCE TEMPERATURE FOR CERTIFICATION TO ENERGY CONSERVATION STANDARDS
Distribution transformer
category
Liquid-immersed .............
Medium-voltage dry-type
Low-voltage dry-type ......
2.3
Reference temperature
20 °C
55 °C
20 °C
75 °C
20 °C
75 °C
for
for
for
for
for
for
no-load loss.
load loss.
no-load loss.
load loss.
no-load loss.
load loss.
Accuracy Requirements
(a) Equipment and methods for loss
measurement must be sufficiently accurate
that measurement error will be limited to the
values shown in Table 2.3.
measurement uncertainty limits specified in
Table 2.3 of this appendix.
*
*
Test system
accuracy
Power Losses ....
Voltage ..............
Current ...............
Resistance .........
Temperature ......
±3.0%.
±0.5%.
±0.5%.
±0.5%.
±1.5 °C for liquid-immersed distribution transformers, and
±2.0 °C for low-voltage dry-type
and medium-voltage dry-type
distribution transformers.
(b) Only instrument transformers meeting
the 0.3 metering accuracy class, or better,
may be used under this test method.
3.0
* * *
3.1
General Considerations
*
*
*
*
*
(c) Measure the direct current resistance
(Rdc) of transformer windings by one of the
methods outlined in section 3.3. The
methods of section 3.5 must be used to
correct load losses to the applicable reference
temperature from the temperature at which
they are measured. Observe precautions
while taking measurements, such as those in
section 3.4, in order to maintain
*
*
3.2.1.1 Methods
Record the winding temperature (Tdc) of
liquid-immersed transformers as the average
of either of the following:
(a) The measurements from two
temperature sensing devices (for example,
thermocouples) applied to the outside of the
transformer tank and thermally insulated
from the surrounding environment, with one
located at the level of the insulating liquid
and the other located near the tank bottom
or at the lower radiator header if applicable;
or
(b) The measurements from two
temperature sensing devices immersed in the
insulating liquid, with one located directly
above the winding and other located directly
below the winding.
TABLE 2.3—TEST SYSTEM ACCURACY
REQUIREMENTS FOR EACH MEAS- 3.2.1.2
URED QUANTITY
*
*
Measured
quantity
*
Conditions
*
*
*
(b) The temperature of the insulating liquid
has stabilized, and the difference between the
top and bottom temperature does not exceed
5 °C. The temperature of the insulating liquid
is considered stable if the top liquid
temperature does not vary more than 2 °C in
a 1-h period.
3.2.2 Dry-Type Distribution Transformers
Record the winding temperature (Tdc) of
dry-type transformers as one of the following:
(a) For ventilated dry-type units, use the
average of readings of four or more
thermometers, thermocouples, or other
suitable temperature sensors inserted within
the coils. Place the sensing points of the
measuring devices as close as possible to the
winding conductors; or
(b) For sealed units, such as epoxy-coated
or epoxy-encapsulated units, use the average
of four or more temperature sensors located
on the enclosure and/or cover, as close to
different parts of the winding assemblies as
possible; or
(c) For ventilated units or sealed units, use
the ambient temperature of the test area, only
if the following conditions are met:
(1) All internal temperatures measured by
the internal temperature sensors must not
differ from the test area ambient temperature
51253
by more than 2 °C. Enclosure surface
temperatures for sealed units must not differ
from the test area ambient temperature by
more than 2 °C.
(2) Test area ambient temperature must not
have changed by more than 3 °C for 3 hours
before the test.
(3) Neither voltage nor current has been
applied to the unit under test for 24 hours.
In addition, increase this initial 24-hour
period by any added amount of time
necessary for the temperature of the
transformer windings to stabilize at the level
of the ambient temperature. However, this
additional amount of time need not exceed
24 hours (i.e., after 48 hours, the transformer
windings can be assumed to have stabilized
at the level of the ambient temperature. Any
stabilization time beyond 48 hours is
optional).
3.3
Resistance Measurement Methods
Make resistance measurements using either
the resistance bridge method (section 3.3.1),
the voltmeter-ammeter method (section 3.3.2)
or resistance meters (section 3.3.3). In each
instance when this appendix is used to test
more than one unit of a basic model to
determine the efficiency of that basic model,
the resistance of the units being tested may
be determined from making resistance
measurements on only one of the units.
*
3.3.2
*
*
*
*
Voltmeter-Ammeter Method
(a) Employ the voltmeter-ammeter method
only if the test current is limited to 15
percent of the winding current. Connect the
transformer winding under test to the circuit
shown in Figure 3.3 of this appendix.
*
*
*
*
*
(b) To perform the measurement, turn on
the source to produce current no larger than
15 percent of the rated current for the
winding. Wait until the current and voltage
readings have stabilized and then take a
minimum of four readings of voltage and
current. Voltage and current readings must be
taken simultaneously for each of the
readings. Calculate the average voltage and
average current using the readings.
Determine the winding resistance Rdc by
using equation 3–4 as follows:
Where:
Vmdc is the average voltage measured by the
voltmeter V; and
Imdc is the average current measured by the
ammeter (A).
tkelley on DSK125TN23PROD with RULES2
*
*
*
*
*
3.3.3 Resistance Meters
Resistance meters may be based on
voltmeter-ammeter, or resistance bridge, or
some other operating principle. Any meter
used to measure a transformer’s winding
resistance must have specifications for
resistance range, current range, and ability to
measure highly inductive resistors that cover
the characteristics of the transformer being
VerDate Sep<11>2014
20:08 Sep 13, 2021
Jkt 253001
tested. Also, the meter’s specifications for
accuracy must meet the applicable criteria of
Table 2.3 in section 2.3 of this appendix.
*
*
*
*
*
3.4.1 Required Actions
The following requirements must be
observed when making resistance
measurements:
*
*
*
*
*
(f) Keep the polarity of the core
magnetization constant during all resistance
measurements.
(g) For single-phase windings, measure the
resistance from terminal to terminal. The
total winding resistance is the terminal-to-
PO 00000
Frm 00025
Fmt 4701
Sfmt 4700
terminal measurement. For series-parallel
windings, the total winding resistance is the
sum of the series terminal-to-terminal section
measurements.
(h) For wye windings, measure the
resistance from terminal to terminal or from
terminal to neutral. For the total winding
resistance, the resistance of the lead from the
neutral connection to the neutral bushing
may be excluded. For terminal-to-terminal
measurements, the total resistance reported is
the sum of the three measurements divided
by two.
(i) For delta windings, measure resistance
from terminal to terminal with the delta
closed or from terminal to terminal with the
E:\FR\FM\14SER2.SGM
14SER2
ER14SE21.014</GPH>
(3-4)
51254
Federal Register / Vol. 86, No. 175 / Tuesday, September 14, 2021 / Rules and Regulations
delta open to obtain the individual phase
readings. The total winding resistance is the
sum of the three-phase readings if the delta
is open. If the delta is closed, the total
winding resistance is the sum of the three
phase-to-phase readings times 1.5.
3.4.2 Guideline for Time Constant
(a) The following guideline is suggested for
the tester as a means to facilitate the
measurement of resistance in accordance
with the accuracy requirements of section
2.3:
*
*
*
*
*
3.5 Conversion of Resistance Measurements
(a) Resistance measurements must be
corrected from the temperature at which the
winding resistance measurements were
made, to the reference temperature.
*
4.0
*
*
*
*
* * *
4.1 General Considerations
The efficiency of a transformer is
computed from the total transformer losses,
which are determined from the measured
value of the no-load loss and load loss power
components. Each of these two power loss
components is measured separately using test
sets that are identical, except that shorting
straps are added for the load-loss test. The
measured quantities need correction for
instrumentation losses and may need
corrections for known phase angle errors in
measuring equipment and for the waveform
distortion in the test voltage. Any power loss
not measured at the applicable reference
temperature must be adjusted to that
reference temperature. The measured load
loss must also be adjusted to a specified
output loading level if not measured at the
specified output loading level. Test all
distribution transformers using a sinusoidal
waveform (k = 1). Measure losses with the
transformer energized by a 60 Hz supply.
*
*
*
*
*
4.3 Test Sets
(a) The same test set may be used for both
the no-load loss and load loss measurements
provided the range of the test set
encompasses the test requirements of both
tests. Calibrate the test set to national
standards to meet the tolerances in Table 2.3
in section 2.3 of this appendix. In addition,
the wattmeter, current measuring system and
voltage measuring system must be calibrated
separately if the overall test set calibration is
outside the tolerance as specified in section
2.3 or the individual phase angle error
exceeds the values specified in section 4.5.3.
*
*
*
*
*
(c) Both load loss and no-load loss
measurements must be made from terminal
to terminal.
*
*
*
*
*
4.4.3.3 Correction of No-Load Loss to
Reference Temperature
After correcting the measured no-load loss
for waveform distortion, correct the loss to
the reference temperature. For both
certification to energy conservation standards
and voluntary representations, if the
correction to reference temperature is
applied, then the core temperature of the
transformer during no-load loss measurement
(Tnm) must be determined within ±10 °C of
the true average core temperature. For
certification to energy conservation standards
only, if the no-load loss measurements were
made between 10 °C and 30 °C, this
correction is not required. Correct the noload loss to the reference temperature by
using equation 4–2 as follows:
(4-2)
Where:
Pnc is the no-load losses corrected for
waveform distortion and then to the
reference temperature;
Pnc1 is the no-load losses, corrected for
waveform distortion, at temperature Tnm;
Tnm is the core temperature during the
measurement of no-load losses; and
Tnr is the reference temperature.
*
*
4.5.3.2
*
*
*
*
Correction for Phase Angle Errors
*
*
*
*
(c) If the correction for phase angle errors
is to be applied, first examine the total
system phase angle (bw¥bv + bc). Where the
total system phase angle is equal to or less
than ±12 milliradians (±41 minutes), use
either equation 4–4 or 4–5 to correct the
measured load loss power for phase angle
errors, and where the total system phase
angle exceeds ±12 milliradians (±41 minutes)
use equation 4–5, as follows:
(4-4)
P1c1
*
*
*
*
= Vzmllm cos( ({J + f3w 5.0
*
f3v
+ f3c)
(4-5)
* * *
5.1 Output Loading Level Adjustment
If the per-unit load selected in section 2.1
is different from the per-unit load at which
the load loss power measurements were
made, then adjust the corrected load loss
power, Plc2, by using equation 5–1 as follows:
*
*
*
VerDate Sep<11>2014
*
Maintain and calibrate test equipment and
measuring instruments, maintain calibration
records, and perform other test and
measurement quality assurance procedures
according to the following sections. The
calibration of the test set must confirm the
accuracy of the test set to that specified in
section 2.3, Table 2.3 of this appendix.
*
20:08 Sep 13, 2021
6.1 Test Equipment
The party performing the tests must
control, calibrate, and maintain measuring
and test equipment, whether or not it owns
the equipment, has the equipment on loan,
or the equipment is provided by another
party. Equipment must be used in a manner
which assures that measurement uncertainty
is known and is consistent with the required
measurement capability.
6.2
Calibration and Certification
*
Jkt 253001
PO 00000
Frm 00026
Fmt 4701
Sfmt 4700
E:\FR\FM\14SER2.SGM
*
*
14SER2
*
*
ER14SE21.017</GPH>
6.0 Test Equipment Calibration and
Certification
ER14SE21.016</GPH>
Where:
Plc is the adjusted load loss power to the perunit load;
Plc2 is as calculated in section 4.5.3.3;
Por is the rated transformer apparent power
(name plate);
Pos is the adjusted rated transformer apparent
power, where Pos = PorL; and
L is the per-unit load, e.g., if the per-unit load
is 50 percent then ‘‘L’’ is 0.5.
ER14SE21.015</GPH>
tkelley on DSK125TN23PROD with RULES2
(5-1)
Federal Register / Vol. 86, No. 175 / Tuesday, September 14, 2021 / Rules and Regulations
(a) Identify the measurements to be made,
the accuracy required (section 2.3) and select
the appropriate measurement and test
equipment;
*
*
*
*
*
tkelley on DSK125TN23PROD with RULES2
7.0 Test Procedure for Voluntary
Representations
Follow sections 1.0 through 6.0 of this
appendix using the per-unit load and/or
VerDate Sep<11>2014
20:08 Sep 13, 2021
Jkt 253001
reference temperature of interest for
voluntary representations of efficiency, and
corresponding values of load loss and noload loss at additional per-unit load and/or
reference temperature. Representations made
at a per-unit load and/or reference
temperature other than those required to
comply with the energy conservation
standards at § 431.196 must be in addition to,
and not in place of, a representation at the
PO 00000
Frm 00027
Fmt 4701
Sfmt 9990
51255
required DOE settings for per-unit load and
reference temperature. As a best practice, the
additional settings of per-unit load and
reference temperature should be provided
with the voluntary representations.
[FR Doc. 2021–19366 Filed 9–13–21; 8:45 am]
BILLING CODE 6450–01–P
E:\FR\FM\14SER2.SGM
14SER2
]]>Agencies
[Federal Register Volume 86, Number 175 (Tuesday, September 14, 2021)]
[Rules and Regulations]
[Pages 51230-51255]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-19366]
[[Page 51229]]
Vol. 86
Tuesday,
No. 175
September 14, 2021
Part II
Department of Energy
-----------------------------------------------------------------------
10 CFR Part 431
Energy Conservation Program: Test Procedure for Distribution
Transformers; Final Rule
Federal Register / Vol. 86 , No. 175 / Tuesday, September 14, 2021 /
Rules and Regulations
[[Page 51230]]
-----------------------------------------------------------------------
DEPARTMENT OF ENERGY
10 CFR Part 431
[EERE-2017-BT-TP-0055]
RIN 1904-AE19
Energy Conservation Program: Test Procedure for Distribution
Transformers
AGENCY: Office of Energy Efficiency and Renewable Energy, Department of
Energy.
ACTION: Final rule.
-----------------------------------------------------------------------
SUMMARY: The U.S. Department of Energy (``DOE'') is amending the test
procedure for distribution transformers to revise and add definitions
of certain terms, update provisions based on the latest versions of
relevant industry testing standards, and to specify the basis for
voluntary representations at additional per-unit loads and additional
reference temperatures. The updates in this final rule will not
significantly change the test procedure.
DATES: The effective date of this rule is October 14, 2021. The final
rule changes will be mandatory for product testing starting March 14,
2022.
ADDRESSES: The docket, which includes Federal Register notices,
comments, and other supporting documents/materials, is available for
review at www.regulations.gov. All documents in the docket are listed
in the www.regulations.gov index. However, some documents listed in the
index, such as those containing information that is exempt from public
disclosure, may not be publicly available.
A link to the docket web page can be found at www.regulations.gov/docket/EERE-2017-BT-TP-0055. The docket web page contains instructions
on how to access all documents, including public comments, in the
docket.
For further information on how to review the docket contact the
Appliance and Equipment Standards Program staff at (202) 287-1445 or by
email: [email protected].
FOR FURTHER INFORMATION CONTACT:
Mr. Jeremy Dommu, U.S. Department of Energy, Office of Energy
Efficiency and Renewable Energy, Building Technologies Office, EE-2J,
1000 Independence Avenue SW, Washington, DC 20585-0121. Telephone:
(202) 586-9870. Email: [email protected].
Mr. Matthew Ring, U.S. Department of Energy, Office of the General
Counsel, GC-33, 1000 Independence Avenue SW, Washington, DC 20585-0121.
Telephone: (202) 586-2555. Email: [email protected].
SUPPLEMENTARY INFORMATION:
Table of Contents
I. Authority and Background
A. Authority
B. Background
II. Synopsis of the Final Rule
III. Discussion
A. Scope of Applicability
B. Updates to Industry Testing Standards
1. Recission of NEMA TP 2
2. Updates to IEEE Standards
C. Definitions
1. Rectifier Transformers and Drive Transformers
2. New Definitions
3. Updated Definitions
D. Per-Unit Load Testing Requirements
1. Multiple-PUL Weighted-Average Efficiency Metric
2. Single-PUL Efficiency Metric
3. Voluntary Representations of Efficiency at Additional PULs
E. Multiple Voltage Capability
F. Other Test Procedure Topics
1. Per-Unit Load Specification
2. Reference Temperature Specification
3. Measurement Location
4. Specification for Stabilization of Current and Voltage
5. Ambient Temperature Tolerances
6. Harmonic Current
7. Other Editorial Revisions
G. Effective and Compliance Dates
H. Test Procedure Costs
IV. Procedural Issues and Regulatory Review
A. Review Under Executive Order 12866
B. Review Under the Regulatory Flexibility Act
C. Review Under the Paperwork Reduction Act of 1995
D. Review Under the National Environmental Policy Act of 1969
E. Review Under Executive Order 13132
F. Review Under Executive Order 12988
G. Review Under the Unfunded Mandates Reform Act of 1995
H. Review Under the Treasury and General Government
Appropriations Act, 1999
I. Review Under Executive Order 12630
J. Review Under Treasury and General Government Appropriations
Act, 2001
K. Review Under Executive Order 13211
L. Review Under Section 32 of the Federal Energy Administration
Act of 1974
M. Congressional Notification
V. Approval of the Office of the Secretary
I. Authority and Background
DOE is authorized to establish and amend energy conservation
standards and test procedures for certain industrial equipment,
including distribution transformers. The current DOE test procedure for
distribution transformers appear at title 10 of the Code of Federal
Regulations (``CFR'') 431.193 and appendix A to subpart K of 10 CFR
part 431 (``appendix A'') respectively. The current energy conservation
standards for distribution transformers appear at 10 CFR 431.196. The
following sections discuss DOE's authority to establish test procedures
for distribution transformers and relevant background information
regarding DOE's consideration of test procedures for this equipment.
A. Authority
The Energy Policy and Conservation Act, as amended (``EPCA''),\1\
authorizes DOE to regulate the energy efficiency of a number of
consumer products and certain industrial equipment. (42 U.S.C. 6291-
6317, as codified) Title III, Part B \2\ of EPCA established the Energy
Conservation Program for Consumer Products Other Than Automobiles (42
U.S.C. 6291-6309, as codified), which sets forth a variety of
provisions designed to improve energy efficiency of specified consumer
products. Title III, Part C \3\ of EPCA, added by the National Energy
Conservation Policy Act, Public Law 95-619, Title IV, section 441(a),
established the Energy Conservation Program for Certain Industrial
Equipment (42 U.S.C. 6311-6317, as codified), which sets forth a
variety of provisions designed to improve energy efficiency of certain
industrial equipment. This equipment includes distribution
transformers, the subject of this final rule. (42 U.S.C. 6317(a))
---------------------------------------------------------------------------
\1\ All references to EPCA in this document refer to the statute
as amended through the Energy Act of 2020, Public Law 116-260 (Dec.
27, 2020).
\2\ For editorial reasons, upon codification in the U.S. Code,
Part B was redesignated Part A.
\3\ For editorial reasons, upon codification in the U.S. Code,
Part C was redesignated Part A-1.
---------------------------------------------------------------------------
The energy conservation program under EPCA consists essentially of
four parts: (1) Testing, (2) labeling, (3) Federal energy conservation
standards, and (4) certification and enforcement procedures. Relevant
provisions of EPCA for distribution transformers specifically include
definitions (42 U.S.C. 6291; 42 U.S.C. 6311), test procedures (42
U.S.C. 6293; 42 U.S.C. 6317), labeling provisions (42 U.S.C. 6294; 42
U.S.C. 6315), energy conservation standards (42 U.S.C. 6295; 42 U.S.C.
6317), and the authority to require information and reports from
manufacturers (42 U.S.C. 6296; 42 U.S.C. 6316).
The Federal testing requirements consist of test procedures that
manufacturers of covered products and covered equipment must use as the
basis for: (1) Certifying to DOE that their products or equipment
comply with the applicable energy conservation standards adopted
pursuant to EPCA (42 U.S.C. 6295(s); 42 U.S.C. 6316(a)), and (2) making
representations about the efficiency of those covered products or
[[Page 51231]]
covered equipment (42 U.S.C. 6293(c); 42 U.S.C. 6314(d)). Similarly,
DOE must use these test procedures to determine whether the products or
equipment comply with relevant standards promulgated under EPCA. (42
U.S.C. 6295(s); 42 U.S.C. 6316(a))
Federal energy efficiency requirements for covered products and
covered equipment established under EPCA generally supersede State laws
and regulations concerning energy conservation testing, labeling, and
standards. (42 U.S.C. 6297; 42 U.S.C. 6316(a) and (b)) DOE may,
however, grant waivers of Federal preemption for particular State laws
or regulations, in accordance with the procedures and other provisions
of EPCA. (42 U.S.C. 6297(d); 42 U.S.C. 6316(b)(2)(D))
EPCA set forth the criteria and procedures DOE must follow when
prescribing or amending test procedures for covered products \4\ and
covered equipment, respectively. EPCA requires that any test procedures
prescribed or amended under these sections be reasonably designed to
produce test results which measure energy efficiency, energy use or
estimated annual operating cost of a covered product during a
representative average use cycle or period of use and not be unduly
burdensome to conduct. (42 U.S.C. 6293(b)(3); see also 42 U.S.C.
6314(a)(2))
---------------------------------------------------------------------------
\4\ DOE generally refers to distribution transformers as covered
equipment. However, to the extent that DOE is discussing provisions
of Part B of EPCA that are applicable to distribution transformers,
``covered product'' is used.
---------------------------------------------------------------------------
EPCA also requires that, at least once every 7 years, DOE evaluate
test procedures for each type of covered product and covered equipment,
including distribution transformers, to determine whether amended test
procedures would more accurately or fully comply with the requirements
for the test procedures to not be unduly burdensome to conduct and be
reasonably designed to produce test results that reflect energy
efficiency, energy use, and estimated operating costs during a
representative average use cycle. (42 U.S.C. 6293(b)(1)(A); see also 42
U.S.C. 6314(a)(1))
If the Secretary determines, on her own behalf or in response to a
petition by any interested person, that a test procedure should be
prescribed or amended, the Secretary shall promptly publish in the
Federal Register proposed test procedures and afford interested persons
an opportunity to present oral and written data, views, and arguments
with respect to such procedures. The comment period on a proposed rule
to amend a test procedure shall be at least 60 days and may not exceed
270 days. In prescribing or amending a test procedure, the Secretary
shall take into account such information as the Secretary determines
relevant to such procedure, including technological developments
relating to energy use or energy efficiency of the type (or class) of
covered products or covered equipment involved. (42 U.S.C. 6293(b)(2))
If DOE determines that test procedure revisions are not appropriate,
DOE must publish its determination not to amend the test procedures.
DOE is publishing this final rule in satisfaction of the 7-year review
requirement specified in EPCA. (42 U.S.C. 6293(b)(1)(A); see also 42
U.S.C. 6314(b)(1))
DOE is issuing this final rule to amend the test procedure for
distribution transformers in accordance with its statutory obligations.
B. Background
With respect to distribution transformers, EPCA states that the
test procedures for distribution transformers shall be based on the
``Standard Test Method for Measuring the Energy Consumption of
Distribution Transformers'' prescribed by the National Electrical
Manufacturers Association (NEMA TP 2-1998). (42 U.S.C. 6293(b)(10)(A))
Further, DOE may review and revise the DOE test procedure. (42 U.S.C.
6293(b)(10)(B))
Consistent with the requirements in EPCA, DOE published a final
rule on April 27, 2006, that established the test procedure for
distribution transformers based on the test methods in NEMA TP 2-1998
and the test methods contained in the Institute of Electrical and
Electronics Engineers (``IEEE'') Standards C57.12.90-1999 and
C57.12.91-2001. 71 FR 24972, 24974. See 71 FR 24972 (April 27, 2006)
(``April 2006 Final Rule'').\5\
---------------------------------------------------------------------------
\5\ DOE published a technical correction to the April 2006 Final
Rule to correct typographical errors. 71 FR 60662 (Oct. 16, 2006).
---------------------------------------------------------------------------
In a final rule published on April 18, 2013, amending the energy
conservation energy conservation standards (``ECS'') for distribution
transformers (``April 2013 ECS Final Rule''), DOE determined that the
test procedure did not require amendment at that time, concluding that
the test procedure as established in the April 2006 Final Rule was
reasonably designed to produce test results that reflect energy
efficiency and energy use, as required by 42 U.S.C. 6314(a)(2). 78 FR
23336, 23347-23348. The current test procedures for distribution
transformers may be found in 10 CFR 431.193 and 10 CFR part 431,
subpart K, appendix A.
On September 22, 2017, DOE published a request for information
(``RFI'') to collect data and information to inform its consideration
of whether to amend DOE's test procedure for distribution transformers
(``September 2017 RFI''). 82 FR 44347. After consideration of comments
received in response to the September 2017 RFI, DOE published a notice
of proposed rulemaking (``NOPR'') on May 10, 2019 (``May 2019 NOPR''),
presenting DOE's proposals to amend the distribution transformer test
procedure. 84 FR 20704.
DOE received comments in response to the May 2019 NOPR from the
interested parties listed in Table I.1.
Table I.1--Written Comments Received in Response to May 2019 NOPR
----------------------------------------------------------------------------------------------------------------
Reference in this
Organization(s) * document Organization type
----------------------------------------------------------------------------------------------------------------
Appliance Standards Awareness Efficiency Advocates.. Efficiency Organizations.
Project, American Council for an
Energy-Efficient Economy, Natural
Resources Defense Council.
Cargill............................. Cargill............... Insulating Liquid Manufacturer.
Copper Development Association...... CDA................... Trade Association.
Howard Industries Inc............... Howard................ Manufacturer.
HVOLT Inc........................... HVOLT................. Industry Consultant.
National Electrical Manufacturers NEMA.................. Trade Association.
Association.
Pacific Gas & Electric Company...... PG&E.................. Electrical Utility.
----------------------------------------------------------------------------------------------------------------
* This list includes only those commenters that provided comments relevant to the May 2019 NOPR.
[[Page 51232]]
A parenthetical reference at the end of a comment quotation or
paraphrase provides the location of the item in the public record.\6\
---------------------------------------------------------------------------
\6\ The parenthetical reference provides a reference for
information located in the docket of DOE's rulemaking to develop
test procedures for distribution transformers. (Docket No. EERE-
2017-BT-STD-0055, which is maintained at www.regulations.gov). The
references are arranged as follows: (commenter name, comment docket
ID number, page of that document).
---------------------------------------------------------------------------
II. Synopsis of the Final Rule
In this final rule, DOE amends 10 CFR 431.192, 431.193, 431.196,
and appendix A as follows:
(1) Explicitly specify that the test procedure is applicable only
to distribution transformers that are subject to energy conservation
standards,
(2) Include new definitions for ``per-unit load,'' ``terminal'' and
``auxiliary device,'' and updated definitions for ``low-voltage dry-
type distribution transformer'' and ``reference temperature,''
(3) Reflect certain revisions from the latest version of the IEEE
testing standards on which the DOE test procedure is based,
(4) Incorporate other clarifying revisions based on review of the
DOE test procedure,
(5) Specify use of existing test procedure provisions for voluntary
(optional) representations at additional per-unit loads (``PULs'') and
reference temperatures, and
(6) Centralize the PUL and reference temperature specifications for
certification to energy conservation standards and for voluntary
representations.
The adopted amendments are summarized in Table II.1 compared to the
test procedure provision prior to the amendment, as well as the reason
for the adopted change. Table II.2 compares the changes adopted in this
final rule to the proposal of the May 2019 NOPR.
Table II.1--Summary of Changes in the Amended Test Procedure
------------------------------------------------------------------------
Amended test
DOE test procedure prior to procedure (adopted Attribution
amendment by this final rule)
------------------------------------------------------------------------
Current test procedure does States explicitly Clarification added
not specify scope. that the scope of by DOE.
the test procedure
is limited to the
scope of equipment
subject to the
energy conservation
standards.
PUL is referred to as Consolidates all Improves consistency
``percent load,'' ``percent terms to only ``per- and readability of
of nameplate-rated load,'' unit load''. test procedure.
``percent of the rated
load,'' or ``per unit load
level''.
Does not define ``Per-unit Adds new definitions Reflects industry
load,'' ``Terminal'' and for ``Per-unit testing standard
``Auxiliary device,'' which load,'' definition
are used in the current ``Terminal,'' and (terminal) and
test procedure (TP). ``Auxiliary clarification added
device''. by DOE (PUL and
auxiliary device).
Includes definition of ``Low- Updates definition Aligns with industry
Voltage Dry-Type of ``Low-Voltage definition.
Distribution Transformer''. Dry-Type
Distribution
Transformer''.
Test procedure provisions Updates provisions Reflects industry
are based on four IEEE based on the latest testing standard
testing standards, which version of the four updates.
contain general IEEE testing
requirements and methods standards:
for performing tests: C57.12.00-2015......
C57.12.00-2000. C57.12.01-2020......
C57.12.01-1998. C57.12.90-2015......
C57.12.90-1999. C57.12.91-2020......
C57.12.91-2001.
Requires reporting States explicitly Update to reflect
performance at the rated that all testing industry testing
frequency; however, the under the DOE test standards.
rated frequency is not procedure is to
explicitly defined. occur only at 60 Hz.
Requires determining winding Specifies that the Update to reflect
resistance but does not polarity of the industry testing
specify whether the core magnetization standards.
polarity of the core be kept constant
magnetization should be during all
kept constant as resistance readings.
measurements are made.
Requires the measurement of Specifies explicitly Update to reflect
load and no-load loss, that load and no- industry testing
without explicitly load loss standards.
specifying the connection measurements are
locations for measurements. required to be
taken only at the
transformer
terminals.
Testing with a sinusoidal Specifies that all Update to reflect
waveform explicitly transformers must industry practice.
specified only for be tested using a
transformers designed for sinusoidal waveform
harmonic currents. (not just those
designed for
harmonic current).
Energy conservation Permits voluntary Response to industry
standards require that representations of comment.
efficiency be determined at efficiency, load
a single PUL of 50 percent loss and no-load
for both liquid-immersed loss at additional
and medium-voltage dry type PULs and/or
(MVDT) distribution reference
transformers, and at 35 temperature, using
percent for low-voltage dry- the DOE test
type (LVDT) distribution procedure. (Does
transformers. not require
certification to
DOE of any
voluntary
representations.)
Specifies PUL and reference Centralizes the PUL Improves readability
temperature specifications and reference of test procedure.
for certification to energy temperature
conservation standards in specifications,
multiple locations both for the
throughout appendix A. certification to
energy conservation
standards and for
use with a
voluntary
representation.
------------------------------------------------------------------------
[[Page 51233]]
Table II.2--Summary of Changes--Final Rule Relative to May 2019 NOPR
------------------------------------------------------------------------
DOE test procedure prior to
amendment NOPR proposal Final rule
------------------------------------------------------------------------
Current test procedure does States explicitly Adopts modification
not specify scope. that the scope of as proposed.
the test procedure
is limited to the
scope of equipment
subject to the
energy conservation
standards.
PUL is referred to as Consolidates all Adopts modification
``percent load,'' ``percent terms to only ``per- as proposed.
of nameplate-rated load,'' unit load.''.
``percent of the rated
load,'' or ``per unit load
level''.
Does not define ``Per-unit Adds new definitions Adopts modification
load,'' ``Terminal'' and for ``Per-unit as proposed.
``Auxiliary device,'' which load,''
are used in the current TP. ``Terminal,'' and
``Auxiliary
device.''.
Aligns definition of ``Low- Proposes updated Slight change from
Voltage Dry-Type definition of ``Low- NOPR to align with
Distribution Transformer'' Voltage Dry-Type industry
with industry definition. Distribution definition.
Transformer.''.
Test procedure provisions Updates provisions Adopts modifications
are based on four IEEE based on the latest as proposed. Note
testing standards, which version of the four that after NOPR
contain general IEEE testing publication, IEEE
requirements and methods standards: updated C57.12.91-
for performing tests: C57.12.00-2015...... 2011 and C57.12.01-
C57.12.00-2000. C57.12.01-2015...... 2015 to C57.12.91-
C57.12.01-1998. C57.12.90-2015...... 2020 and C57.12.01-
C57.12.90-1999. C57.12.91-2011...... 2020. The relevant
C57.12.91-2001. provisions of
C57.12.91-2020 and
C57.12.01-2020 and
the other two
testing standards
are unchanged.
Automatic Recording of Data Requires automatic NOPR proposal not
Not Required. recording of data, adopted in this
as required in IEEE final rule.
C57.12.90-2015 and
IEEE C57.12.91-
2011, using a
digital data
acquisition system.
(Appendix A,
section 4.4.2(b)).
Requires reporting States explicitly Adopted no-load loss
performance at the rated that all testing test as proposed.
frequency; however, the under the DOE test NOPR proposal not
rated frequency is not procedure is to adopted for
explicitly defined. occur only at 60 Hz resistance
for resistance measurements.
measurement and no-
load loss test.
Requires determining winding Specifies that the Adopts modification
resistance but does not polarity of the as proposed.
specify whether the core magnetization
polarity of the core be kept constant
magnetization should be during all
kept constant as resistance readings.
measurements are made.
Requires the measurement of Specifies explicitly Adopts modification
load and no-load loss, that load and no- as proposed.
without explicitly load loss
specifying the connection measurements are
locations for measurements. required to be
taken only at the
transformer
terminals.
Testing with a sinusoidal Specifies that all Adopts modification
waveform explicitly transformers must as proposed.
specified only for be tested using a
transformers designed for sinusoidal waveform
harmonic currents. (not just those
designed for
harmonic current).
Energy conservation Permits voluntary Adopts modification
standards require that representations of as proposed.
efficiency be determined at efficiency, load
a single PUL of 50 percent loss and no-load
for both liquid-immersed loss at additional
and MVDT distribution PULs and/or
transformers, and at 35 reference
percent for LVDT temperature, using
distribution transformers. the DOE test
procedure. (Does
not require
certification to
DOE of any
voluntary
representations.)
Specifies PUL and reference Centralizes the PUL No change from NOPR.
temperature specifications and reference
for certification to energy temperature
conservation standards in specifications,
multiple locations both for the
throughout appendix A. certification to
energy conservation
standards and for
use with a
voluntary
representation.
------------------------------------------------------------------------
DOE has determined that the amendments described in section III and
adopted in this document will not alter the measured efficiency of
distribution transformers or require retesting or recertification
solely as a result of DOE's adoption of the amendments to the test
procedure. Additionally, DOE has determined that the amendments will
not increase the cost of testing. Discussion of DOE's actions are
addressed in detail in section III of this document.
The effective date for the amended test procedure adopted in this
final rule is 30 days after publication of this document in the Federal
Register. Representations of energy use or energy efficiency must be
based on testing in accordance with the amended test procedure
beginning 180 days after the publication of this final rule.
III. Discussion
A. Scope of Applicability
The applicability of the test procedure is provided in 10 CFR
431.193, which states that ``the test procedures for measuring the
energy efficiency of distribution transformers for purposes of EPCA are
specified in appendix A to this subpart.'' DOE has established energy
conservation standards for low-voltage dry-type (``LVDT'') distribution
transformers, liquid-immersed distribution transformers, and medium-
voltage dry type (``MVDT'') distribution transformers at 10 CFR
431.196. In the May 2019 NOPR, DOE proposed to state explicitly that
the scope of the test procedure is limited to the scope of the
distribution transformers that are subject to energy conservation
standards. 84 FR 20704, 20706. DOE did not receive any comments
regarding this proposal. DOE is modifying text in 10 CFR 431.193
regarding the scope of the test procedure as proposed.
[[Page 51234]]
B. Updates to Industry Testing Standards
The current DOE test procedure for distribution transformers is
based on provisions from the following industry testing standards (See
71 FR 24972, 24982 (April 27, 2006)):
NEMA TP 2-1998, ``Standard Test Method for Measuring the
Energy Consumption of Distribution Transformers'' (NEMA TP 2-1998)
IEEE C57.12.90-1999, ``IEEE Standard Test Code for Liquid-
Immersed Distribution, Power and Regulating Transformers and IEEE Guide
for Short Circuit Testing of Distribution and Power Transformers''
IEEE C57.12.91-2001, ``IEEE Standard Test Code for Dry-Type
Distribution and Power Transformers''
IEEE C57.12.00-2000, ``IEEE Standard General Requirements for
Liquid-Immersed Distribution, Power and Regulating Transformers''
IEEE C57.12.01-1998, ``IEEE Standard General Requirements for
Dry-Type Distribution and Power Transformers Including those with Solid
Cast and/or Resin Encapsulated Windings''
In addition, the DOE test procedure is also based on provisions in
NEMA TP 2-2005,\7\ which in turn reference the aforementioned IEEE
testing standards.\8\ DOE determined that basing the procedure on
multiple industry testing standards, as opposed to adopting an industry
test procedure (or procedures) without modification, was necessary to
provide the detail and accuracy required for the Federal test
procedure, with the additional benefit of providing manufacturers the
Federal test procedure in a single reference. 71 FR 24972, 24982 (April
27, 2006).
---------------------------------------------------------------------------
\7\ Standard Test Method for Measuring the Energy Consumption of
Distribution Transformers, available at: nema.org/Standards/Pages/Standard-Test-Method-for-Measuring-the-Energy-Consumption-of-Distribution-Transformers.aspx.
\8\ Prior to the April 2006 Final Rule, NEMA provided the
Department with its revised test procedure document (i.e., update to
NEMA TP 2-1998), TP 2-2005. The Department treated this submission
as a comment on DOE's rulemaking to establish a distribution
transformer test procedure. 71 FR 24972, 24973. As such, the DOE
test procedure incorporated a number of the changes that this
revision made to the rule language and addressed the differences
between the DOE test procedure and NEMA TP 2-2005. Id.
---------------------------------------------------------------------------
DOE previously sought comment on the benefits and burdens of
adopting industry testing standards without modification. 82 FR 44347,
44351 (Sep. 22, 2017). NEMA commented generally that there is benefit
but that DOE should limit the reference to the measurement of losses
and retain DOE's existing calculation for efficiency. (NEMA, Docket No.
EERE-2017-BT-TP-0055-0014 p. 9) DOE stated in the May 2019 NOPR that
the current test procedure is already based on industry testing
standards and that if DOE were to adopt an industry testing standard
without modification, the resulting changes could require manufacturers
to retest and recertify, because such an incorporation by reference
would require updating a majority of the current test procedure. 84 FR
20704, 20710. For these reasons, DOE did not propose to incorporate
industry testing standard into its test procedure for distribution
transformers. Id.
NEMA further commented that while the existing test procedure is
adequate, for high volume units the test procedures found in IEEE
C57.12.90-2015 and IEEE C.57.12.91-2011 are less burdensome and
recommended that DOE allow them as equivalent alternatives for the
purposes of testing and certification. (NEMA, No. 30 at p. 5) As
discussed, DOE's test procedure is partially based on the IEEE testing
standards, and there are similarities between the DOE test procedure
and the IEEE testing standards. There are also minor differences
between the DOE test procedure and the IEEE testing standards, such as
DOE's requirement to test multiple-voltage-capable distribution
transformers in the highest losses configuration (appendix A, sections
4.5.1(b) and 5.0), as discussed in section III.E. Testing according to
the IEEE test procedures without modification could result in
distribution transformers being tested at different conditions
depending on the method used. Therefore, DOE is not permitting use of
IEEE testing standards as equivalent alternatives. DOE may consider
referencing sections of the IEEE test procedures as equivalent in the
future if there is sufficient data and information that doing so would
result in equivalent measured efficiency values with the DOE test
procedure.
1. Recission of NEMA TP 2
As discussed, EPCA requires that DOE base the test procedure on
NEMA TP 2-1998. (42 U.S.C. 6293(b)(10)(A)) Also as discussed, the DOE
test procedure is based on (but does not incorporate by reference
directly) NEMA TP 2-1998, NEMA TP 2-2005, as well as four IEEE
standards that are referenced in NEMA TP 2-2005, i.e., IEEE.C57.12.00,
IEEE C57.12.01, IEEE C57.12.90 and IEEE C57.12.91. See 71 FR 24972,
24982 (April 27, 2006). As discussed in the following section, updates
have been made to the IEEE testing standards.
Since publication of the April 2006 Final Rule, NEMA TP 2-2005 has
been rescinded and superseded in industry by the IEEE standards. DOE
has evaluated the provisions in the Federal test procedure that are
based on NEMA TP 2 and, as discussed in the May 2019 NOPR, has
determined that these provisions remain appropriate for testing
distribution transformers. DOE did not receive any comments on these
provisions in the May 2019 NOPR and therefore maintained them in this
final rule.
2. Updates to IEEE Standards
a. Background
As discussed in section III.B, the DOE test procedure mirrors four
widely used IEEE testing standards. Since the April 2006 Final Rule,
all of the four IEEE standards have been updated.
In the May 2019 NOPR, DOE proposed updating certain Federal test
procedure provisions to reflect the following updated versions of the
relevant IEEE testing standards: IEEE C57.12.90-2015, IEEE C57.12.91-
2011, IEEE C57.12.00-2015, and IEEE C57.12.01-2015. Since publication
of the May 2019 NOPR, IEEE issued a further update to standard IEEE
C57.12.91 (IEEE C57.12.91-2020) and IEEE C57.12.01-2015 (IEEE
C57.12.01-2020). Table III.1 provides a list of old and new versions of
each of these IEEE testing standards.
[[Page 51235]]
Table III.1--IEEE Industry Testing Standards Versions and Summary
------------------------------------------------------------------------
Version on which
DOE test Most recent
IEEE standard procedure prior IEEE revision Content
to amendment is version (year)
based (year)
------------------------------------------------------------------------
C57.12.00............ 2000 2015 General
electrical and
mechanical
requirements
for liquid-
immersed
distribution
transformers.
C57.12.01............ 1998 2020 General
electrical and
mechanical
requirements
for dry-type
distribution
transformers.
C57.12.90............ 1999 2015 Methods for
performing
tests
specified in
C57.12.00 and
others for
liquid-
immersed
distribution
transformers.
C57.12.91............ 2001 2020 Methods for
performing
tests
specified in
C57.12.01 and
others for dry-
type
distribution
transformers.
------------------------------------------------------------------------
b. General Updates
For the May 2019 NOPR, DOE reviewed the then most current editions
of the relevant IEEE testing standards to determine whether any of the
updates from the previously considered versions warranted proposed
amendments to the DOE test procedure. The four IEEE testing standards
are not relevant to the DOE test procedure in their entirety, as they
include specifications and test methods beyond those required to
measure efficiency, such as test methods for polarity, phase-relation,
dielectric, and audible sound-level. DOE performed the review as
follows:
(1) DOE identified the sections of the IEEE testing standards that
form the basis of the DOE test procedure,
(2) DOE compared those sections between the old and the then
current versions of the IEEE testing standards, and
(3) DOE initially determined which of the changes were editorial
versus which represented potential substantive improvements to the test
method.
In IEEE C57.12.90-2015 and IEEE C57.12.91-2011, sections 5, 8, and
9 provide the resistance measurements, the no-load loss test, and the
load loss test, respectively, which provide the basis for the DOE test
procedure. In general, DOE did not identify major changes in sections
5, 8, and 9 between 1999 and 2015 editions of IEEE C57.12.90-2015, or
between the 2001 and 2011 editions of IEEE C57.12.91-2011. Since the
May 2019 NOPR, DOE has reviewed the updated IEEE C57.12.91-2020 test
procedure and concluded that there were no substantive differences
between the relevant provisions in the 2011 and 2020 versions.
The IEEE C57.12.00 and IEEE C57.12.01 testing standards include
general electrical and mechanical requirements for the test methods for
liquid-immersed and dry-type distribution transformers, in IEEE
C57.12.90 and IEEE C57.12.91, respectively. In IEEE C57.12.00 and IEEE
C57.12.01, section 9 and section 5, respectively, provide accuracy
requirements for conducting the resistance measurements, the no-load
loss test, and the load loss test. The primary change DOE identified in
the accuracy requirements between the 2000 and 1998 standards and the
2015 standards was a slight relaxation of the temperature system
accuracy requirement, from 1 [deg]C in the older versions
to 1.5 [deg]C for liquid-immersed distribution transformers
and 2 [deg]C for medium-voltage dry-type distribution
transformers and low-voltage dry-type distribution transformers. Since
the May 2019 NOPR, DOE has reviewed the updated IEEE C57.12.91-2020
test procedure and concluded that there were no substantive differences
between the relevant provisions in the 2015 and 2020 versions.
In the May 2019 NOPR, DOE proposed a series of updates based on the
then most recent updates to the relevant IEEE testing standards. 84 FR
20704, 20711. DOE stated the proposed updates reflect current industry
practice, and as such, would not change current measured values. Id.
DOE further stated that providing additional specificity consistent
with the updates would improve the repeatability of the test procedure.
Id. DOE requested comment on the proposed changes to reflect the
updates to the relevant IEEE testing standards. Id.
DOE received comments from Howard, NEMA, CDA, and HVOLT agreeing
that the proposed updates are already industry practice and would not
change any values or increase testing costs for manufacturers. (Howard,
No. 32 at p.1; NEMA, No. 20 at p. 3; CDA, No. 29 at p. 2; HVOLT, No. 27
at p. 91)
Based on its review of the updates to the relevant IEEE testing
standards and following consideration of the comments, DOE is adopting
the proposed updates and clarifications, with two exceptions, discussed
below.
c. Automatic Recording of Data
In the May 2019 NOPR, DOE proposed to require automatic recording
of data using a digital data acquisition system at appendix A, section
4.4.2(b), in an attempt to align with industry standards. 84 FR 20704,
20711. NEMA commented that the proposed requirement to automatically
record data using a digital data acquisition system is listed in IEEE
C57.12.90-2015 and C57.12.91-2020 for making resistance measurements by
the voltmeter-ammeter method, and not for the no-load loss measurements
as was proposed in the May 2019 NOPR. (NEMA, No. 30 at p. 3) NEMA
commented that requiring automatic recording of data using a digital
data acquisition system for the no-load losses could require some labs
to upgrade test equipment, as not all power analyzers have this
capability. Id.
DOE acknowledges that IEEE C57.12.90-2015 and C57.12.91-2020 both
cite using digital data acquisition systems for making resistance
measurements by the voltmeter-ammeter method and not for no-load
losses, as was proposed. In an effort to remain aligned with the
industry testing standard IEEE C57.12.90-2015 and C57.12.91-2020 no-
load loss test, DOE has not adopted the proposal to require automatic
recording of data using a digital data acquisition system. DOE is
maintaining the current specification in section 4.4.2(b) of appendix A
that requires recording data ``as close to simultaneously as
possible.''
d. Test Frequency
In the May 2019 TP NOPR, DOE proposed to require testing under the
DOE test procedure to occur only at 60 Hz in appendix A, sections
3.1(c) and 4.1, in order to align with the industry testing standard
and provide clarity on the frequency of the test current. 84 FR 20704,
20711.
NEMA commented that there was an error in the proposed language of
[[Page 51236]]
section 3.1(c) of Appendix A, stating that the proposed regulatory text
should read ``Measure resistance with the transformer energized by a DC
supply'' rather than with a 60 Hz supply as was proposed in the May
2019 NOPR. (NEMA, No. 30 at p. 5) DOE concurs with NEMA that the 60 Hz
supply frequency is not applicable to the resistance measurement
section of the test procedure, only to the loss measurement sections.
The proposed addition of section 3.1(c) of appendix A, was an error.
Resistance measurements are already stated as being a ``direct current
resistance'' measurement in appendix A, section 3.1(b). Therefore, DOE
is not adopting section 3.1(c) of appendix A as was proposed in the May
2019 NOPR.
The proposed language clarifying the ``Test Frequency'' provision
in appendix A, section 4.1, is aligned with the industry standard to
test at the ``rated frequency,'' which by the definition of
distribution transformer at 10 CFR 431.192 is 60Hz. Therefore, this
proposed addition remains appropriate. DOE did not receive any comment
in opposition to its proposal to clarify that appendix A, section 4.1,
is to be conducted with a 60 Hz frequency current. Therefore, DOE is
adopting the change as proposed to section 4.1.
e. Summary of Updates Adopted in This Final Rule
Table III.2 summarizes proposed updates to the relevant IEEE
testing standards that are adopted in this final rule. As summarized
previously, DOE received comments from industry trade organizations and
individual manufacturers indicating that the proposed updates are
already industry practice and would not change any values or increase
testing costs for manufacturers. (Howard, No. 32 at p. 1; NEMA, No. 30
at p. 3; CDA, No. 29 at p. 2; HVOLT, No. 27 at p. 91) As such, DOE has
determined that the following amendments reflect current industry
practice and provide additional specificity that will improve the
repeatability of the test procedure.
Table III.2--IEEE-Based Updates Adopted in This Final Rule
------------------------------------------------------------------------
Topic Updates based on IEEE standards
------------------------------------------------------------------------
Consolidating the Terms ``Oil,'' Replace the term ``oil'' and
``Transformer Liquid,'' and ``transformer liquid'' with
``Insulating Liquid''. ``insulating liquid'' in
Appendix A to reflect that the
term is inclusive of all
insulating liquids, including
those identified in IEEE
C57.12.90-2015.
Stability Requirement for Resistance Specify, consistent with IEEE
Measurement. C57.12.90-2015, that
resistance measurements are
considered stable if the top
insulating liquid temperature
does not vary more than 2
[deg]C in a one-hour period.
(Appendix A, section
3.2.1.2(b))
Temperature Test System Accuracy....... Relax the temperature test
system accuracy requirements
to be within 1.5
[deg]C for liquid-immersed
distribution transformers, and
2.0 [deg]C for
MVDT and LVDT distribution
transformers, as specified in
IEEE C57.12.00-2015 and IEEE
C57.12.01-2020, respectively.
(Appendix A, section 2.0)
Limits for Voltmeter-Ammeter Method.... Permit use of the voltmeter-
ammeter method when the rated
current of the winding is less
than or equal to 1 A. Neither
IEEE C57.12.90-2015 nor IEEE
C57.12.91-2020 restrict usage
of this method to certain
current ranges. (Appendix A,
section 3.3.2(a))
Number of Readings Required for Include the requirement that a
Resistance Measurement. minimum of four readings for
current and voltage must be
used for each resistance
measurement, as specified in
IEEE C57.12.90-2015. (Appendix
A, section 3.3.2(b))
Connection Locations for Resistance Add resistance measurement
Measurements. specifications for single-
phase windings, wye windings
and delta windings, as
provided in section 5.4.1 and
5.4.2 of IEEE C57.12.90-2015,
and sections 5.6.1 through
5.6.3 of IEEE C57.12.91-2020.
(Appendix A, section 3.4.1(g)-
(i))
Test Frequency......................... Require that all testing under
the DOE test procedure is to
occur only at 60 Hz. (Appendix
A, section 4.1)
Polarity of Core Magnetization......... Require that the polarity of
the core magnetization be kept
constant during all resistance
readings. (Appendix A, section
3.4.1(f))
------------------------------------------------------------------------
C. Definitions
Definitions pertaining to distribution transformers are provided at
10 CFR 431.192. The following sections discuss new and amended
definitions established in this final rule.
1. Rectifier Transformers and Drive Transformers
DOE defines rectifier transformer as a transformer that operates at
the fundamental frequency of an alternating-current system and that is
designed to have one or more output windings connected to a
rectifier.\9\ 10 CFR 431.192.
---------------------------------------------------------------------------
\9\ A rectifier is an electrical device for converting
alternating current to direct current.
---------------------------------------------------------------------------
DOE defines drive (isolation) transformer as a transformer that (1)
isolates an electric motor from the line; (2) accommodates the added
loads of drive-created harmonics; and (3) is designed to withstand the
mechanical stresses resulting from an alternating current adjustable
frequency motor drive or a direct current motor drive. 10 CFR 431.192.
The parenthetical inclusion of the term ``isolation'' indicates that
the defined term includes only isolation transformers and not other
transformers that may be described as ``drive transformers'' in the
industry but which do not satisfy all three criteria specified in the
definition of drive (isolation) transformer.
Both rectifier transformers and drive transformers are among the
exclusions to the term ``distribution transformer'' at 10 CFR 431.192
and 42 U.S.C. 6293(35)(B)(ii). Because both rectifier transformers and
drive transformers are not classified as distribution transformers,
they are not subject to the energy conservation standards at 10 CFR
431.196.
[[Page 51237]]
Although rectifier transformers and drive transformers are defined
differently, they typically share features. As discussed in the May
2019 NOPR, both are isolation transformers (i.e., not
autotransformers); both are typically exposed to (and must tolerate)
significant harmonic content created from the drive or power supply;
and both are likely to include design features enabling them to bear
mechanical stress resulting from rapid current changes that may arise
from operation of motors and other industrial equipment. 84 FR 207054,
20708.
In response to the September 2017 RFI, Babanna Suresh (``Suresh'')
commented that it could be argued that most distribution-type
transformers meet the present definition of the terms ``rectifier
transformer'' or ``drive transformer'' and suggested that those terms
be removed from the list of exclusions to the term ``distribution
transformer.'' (Suresh, Docket No. EERE-2017-BT-TP-0055, No. 9 at p. 1)
Suresh further suggested that the definition of ``rectifier
transformer'' be limited to transformers that supply loads that are
composed of at least 75 percent power electronics. Id.
In the May 2019 NOPR, DOE stated that the definition of ``rectifier
transformer'' is not intended to cover a large number of transformers
intended for general power service; and that linking the definition to
a percentage of supply load from power electronics would be
insufficient to designate a distribution transformer because it may not
be possible for a manufacturer to know in advance what fraction of a
distribution transformer's load will include power electronics. 84 FR
207054, 20708. Based on further review of industry testing standards
and available manufacturer literature, DOE further stated that it was
unable to identify physical attributes that could be used to reliably
identify rectifier transformers. Id.
DOE requested comment on whether the current definitions of
rectifier transformer and drive transformer are sufficiently specific;
the level of technical similarity between the two types of
transformers; and whether any physical or electrical properties could
be used to reliably identify rectifier transformers.
DOE received written comments from CDA and HVOLT stating that
defining rectifier transformers as having multiple output windings
could be a reasonable addition. (CDA, No. 29 at p.1; HVOLT No. 27 at p.
89) DOE notes that the current definition already specifies that
rectifier transformers can have ``one or more'' output windings. 10 CFR
431.192.
CDA and HVOLT also stated that small drive transformers could meet
energy conservations standards, but that larger drive transformers are
more complicated and would have a more difficult time meeting
standards. (CDA, No. 29 at p.1-2; HVOLT No. 27 at p. 89) While smaller
drive transformers may be able to meet energy conservation standards,
the statutory definition for distribution transformer excludes any
transformer that is designed to be used in a special purpose
applications and is unlikely to be used in general purpose
applications, and specifies drive transformers as such an example. 42
U.S.C. 6291(35)(b)(ii).
NEMA commented that the current definition for both rectifier
transformer and drive transformer are sufficient. (NEMA, No. 30 at
p.2).
Having considered these comments from interested parties, DOE
remains unaware of any industry definition or physical features that
would better define either rectifier transformers or drive
transformers.
Therefore, DOE makes no changes to the definitions of ``rectifier
transformer'' and ``drive transformer'' in this final rule. Both
varieties of equipment remain excluded from energy conservation
standards and are therefore excluded from the scope of the test
procedure (in accordance with the amendment discussed in section III.A
of this final rule specifying that the scope of the test procedure is
limited to the scope of the distribution transformers that are subject
to energy conservation standards). However, as stated in the April 2006
Final Rule, DOE narrowly construes the exclusions from the definition
of ``distribution transformer.'' DOE will also take appropriate steps,
including enforcement action if necessary, if any manufacturer or other
party erroneously invokes one of the exclusions as a basis for
marketing a transformer that is a ``distribution transformer,'' but
does not meet DOE standards. Moreover, to the extent transformers that
do fall within the exclusions begin to be marketed for standard
distribution applications, or find widespread use in such applications,
DOE will examine whether re-defining the relevant exclusions is
warranted. See 71 FR 24979.
2. New Definitions
In the May 2019 NOPR, DOE proposed and sought comment on
definitions for the terms ``per-unit load,'' ``terminal,'' and
``auxiliary device.'' 84 FR 20704, 20708-20709. These terms are
referenced in the DOE test procedure but are not currently defined in
the regulatory text. The following sections discuss comments received
regarding each of these terms and the definitions established in this
final rule.
a. Per-Unit Load
Distribution transformers are regularly operated at capacities
other than the capacity listed on a distribution transformer's
nameplate (i.e., the rated load). In general, distribution transformers
are loaded substantially below their rated load. DOE's current test
procedure and energy conservation standards for distribution
transformers use various terms to refer to operating or testing a
distribution transformer at a capacity other than the rated load,
including ``percent load,'' ``percent of nameplate-rated load,''
``percent of the rated load,'' or ``per unit load level.'' 10 CFR
431.192, 10 CFR 431.196, and appendix A. DOE proposed to consolidate
the usage of these various terms into a single term, ``per-unit load''
(``PUL'') in all instances identified. 84 FR 20704, 20709. DOE also
proposed to define ``per-unit load'' to mean the fraction of rated
load. Id.
Howard, CDA, and HVOLT supported the proposed term per-unit load.
(Howard, No. 32 at p.1; CDA, No. 29 at p.2; HVOLT, No. 27 at p. 89) DOE
did not receive any comments against its proposed definition for per-
unit load or its proposal to consolidate all references to partial
loading into a single per-unit load term. In order to improve the
readability of the test procedure, DOE is adopting the proposed
definition for per-unit load at 10 CFR 431.192. DOE is also
consolidating all references to partial load operation in 10 CFR
431.192, 10 CFR 431.196, and appendix A to the defined ``per-unit
load'' term.
b. Terminal
In the May 2019 NOPR, DOE proposed to clarify that load and no-load
loss measurements should be taken only at the distribution transformer
terminals, as discussed in section III.F.3. As such, DOE proposed to
define ``terminal'' to mean ``a conducting element of a distribution
transformer providing electrical connection to an external conductor
that is not part of the transformer.'' 84 FR 20704, 20709. This
definition is based on, but not identical to, the definition for
``terminal'' in IEEE C57.12.80-2010,\10\ ``IEEE Standard
[[Page 51238]]
Terminology for Power and Distribution Transformers.'' IEEE C57.12.80-
2010 defines terminal as ``(A) A conducting element of an equipment or
a circuit intended for connection to an external conductor. (B) A
device attached to a conductor to facilitate connection with another
conductor.''
---------------------------------------------------------------------------
\10\ IEEE C57.12.80-2010 is currently listed as ``inactive-
reserved'' which means that this standard is ``. . . removed from
active status through an administrative process for standards that
have not undergone a revision process within 10 years.'' (See
www.standard.iee.org). Given that the standard has not been
superseded and is not listed as inactive-withdrawn, DOE is
continuing to consider it the current industry standard on standard
terminology for power and distribution transformers.
---------------------------------------------------------------------------
Howard commented in agreement with the proposed definition.
(Howard, No. 32 at p.1) NEMA, CDA and HVOLT preferred DOE to adopt the
IEEE C57.12.80-2010 definition of ``terminal'' directly. (NEMA, No. 30
at p. 2; CDA, No. 29 at p. 2; HVOLT, No. 27 at p. 90).
DOE has reviewed the IEEE definition and while part ``(A)'' is
similar to the definition proposed in the May 2019 NOPR, part ``(B)''
does not clarify that the terminal needs to be external. While adoption
of industry-developed language would promote further consistency
between the DOE test procedure and the industry testing standards, DOE
is concerned that the IEEE definition could be understood to exclude
busbar losses in testing of distribution transformers because part (B)
of the IEEE definition does not specify that a terminal is for
connection to an external conductor. A manufacturer could interpret
terminal to be any conducting element within the distribution
transformer, including a conducting element between the busbar and the
windings. As a result, DOE is adopting the definition of ``terminal''
proposed in the May 2019 NOPR at 10 CFR 431.192 as ``a conducting
element of a distribution transformer providing electrical connection
to an external conductor that is not part of the transformer.''
c. Auxiliary Device
Section 4.5.3.1.2 of appendix A specifies that during testing,
``measured losses attributable to auxiliary devices (e.g., circuit
breakers, fuses, switches) installed in the transformer, if any, that
are not part of the winding and core assembly, may be excluded from
load losses measured during testing.'' DOE has received inquiries from
manufacturers regarding whether certain other internal components of
distribution transformers are required by the DOE test procedure to be
included in the loss calculation, or whether they are considered an
auxiliary device. In the May 2019 NOPR, DOE proposed to address the
prior industry questions and establish a definition of the term
``auxiliary device'' based on a specific list of all components and/or
component functions that would be considered auxiliary devices and,
therefore, be optionally excluded from measurement of load loss during
testing. 84 FR 20704, 20709.
The auxiliary device examples listed at section 4.5.3.1.2 of
appendix A (circuit breakers, fuses, and switches) all provide
protective function, but do not directly aid the transformer's core
function of supplying electrical power. Additionally, the term
``device'' indicates a localized nature, rather than a diffuse system
or property of the transformer.
DOE proposed to define ``auxiliary device'' to mean ``a localized
component of a distribution transformer that is a circuit breaker,
switch, fuse, or surge/lightning arrester.'' DOE requested comment on
the proposed definition, if any components needed to be added or
removed from the listed auxiliary devices, and whether it is
appropriate to include functional component designations as part of a
definition. Id.
CDA and HVOLT stated that the proposed definition was adequate.
(CDA, No. 29 at p.2; HVOLT, No. 27 at p. 90) Howard commented that the
four components listed are sufficient and a functional designation is
not needed. (Howard, No. 32 at p.1) NEMA commented that the current
definitions are adequate and that it is not necessary to define
auxiliary device. (NEMA, No. 39 at p.2) NEMA did not specify what, if
any, aspects of the proposed definition would be inadequate. Moreover,
prior inquiries from industry indicate that the definition of
``auxiliary device'' would benefit from further detail. DOE did not
receive any comment suggesting that the proposed definition is
inadequate. DOE is adopting the definition of auxiliary device in this
final rule as proposed.
3. Updated Definitions
a. Low-Voltage Dry-Type Distribution Transformer
EPCA defines a ``low-voltage dry-type distribution transformer'' as
``a distribution transformer that--(1) Has an input voltage of 600
volts or less; (2) is air-cooled; and (3) does not use oil as a
coolant.'' 42 U.S.C. 6291(38).
In the May 2019 NOPR, DOE proposed to update the definition for
``low-voltage dry-type distribution transformer'' by replacing the term
``oil'' with ``insulating liquid'' within the definition, in
conjunction with DOE's proposal to consolidate multiple terms to
``insulating liquid,'' as described in section III.B.2. 84 FR 20704,
20709. DOE proposed this update to reflect that the term is inclusive
of all insulating liquids, including those identified in IEEE
C57.12.90-2015. Id.
Howard, CDA, and HVOLT generally supported using the broader term
``insulating liquid'' rather than ``oil.'' (Howard, No. 32 at p. 1;
CDA, No. 29 at p. 2; HVOLT, No. 27 at p.91) NEMA recommended
harmonizing the definition with the definition provided in IEEE
C57.12.80-2010. (NEMA, No. 30 at p. 3) IEEE defines a ``low-voltage
dry-type distribution transformer'' to mean ``a distribution
transformer that--(1) Has an input voltage of 600 volts or less; (2)
Has the core and coil assembly immersed in a gaseous or dry-compound
insulating medium.''
Of the three components of EPCA's definition of ``low-voltage dry-
type distribution transformer'', the first component (``Has an input
voltage of 600 volts or less'') was not proposed for revision by either
the May 2019 NOPR or by commenters. 42 U.S.C. 6291(38). This first
component of the definition is left unchanged by this final rule.
Whereas the first component of the definition addresses the ``low-
voltage'' portion of term ``low-voltage dry-type distribution
transformer'', the second and third components (``is air-cooled'';
``does not use oil as a coolant'') combine to describe the manner in
which LVDTs dissipate heat and collectively address the ``dry-type''
portion of the term. The comment from NEMA (suggesting that DOE amend
the definition to reference the core and coil assembly being ``immersed
in a gaseous or dry-compound insulating medium'') indicates that
industry generally considers the descriptors ``air cooled; does not use
oil as a coolant'' to be synonymous with ``immersed in a gaseous or
dry-compound insulating medium.'' The revision suggested by NEMA would
also be consistent with DOE's terminology for addressing ``dry type''
in the definition of ``medium-voltage dry-type distribution
transformer'', which DOE defines as a distribution transformer in which
the core and coil assembly is immersed in a gaseous or dry-compound
insulating medium, and which has a rated primary voltage between 601 V
and 34.5 kV. 10 CFR 431.192.
After further consideration of the May 2019 NOPR proposal, and
consideration of comments from interested parties in response to that
proposal, this final rule revises the definition of ``low-voltage dry-
type distribution transformer'' to mean ``a distribution transformer
that has an input voltage of 600 volts or less and has the core and
coil assembly immersed in a gaseous or dry-
[[Page 51239]]
compound insulating medium.'' This revised wording harmonizes with the
industry definition and implements consistent terminology across both
varieties of dry-type distribution transformers (i.e., low-voltage and
medium-voltage).
b. Reference Temperature
The reference temperature is the temperature at which the
transformer losses must be determined, and to which such losses must be
corrected if testing is performed at a different temperature. As
currently defined at 10 CFR 431.192, ``reference temperature'' means 20
[deg]C for no-load loss, 55 [deg]C for load loss of liquid-immersed
distribution transformers at 50 percent load, and 75 [deg]C for load
loss of both low-voltage and medium-voltage dry-type distribution
transformers, at 35 percent load and 50 percent load, respectively.
In the May 2019 NOPR, DOE proposed to update the definition for
``reference temperature'' by removing references to the numerical
temperature values required for certification with energy conservation
standards. 84 FR 20704, 20709. DOE proposed to retain the conceptual
definition of reference temperature and to include in appendix A the
numerical temperature values for certification with energy conservation
standards. The updated definition would allow use of the term reference
temperature outside the context of conditions required for
certification with energy conservation standards (i.e., voluntary
representations at additional temperature values, as described in
section III.D.2.b). DOE proposed ``reference temperature'' to mean the
temperature at which the transformer losses are determined, and to
which such losses must be corrected if testing is performed at a
different temperature.
Howard and NEMA both supported the updated definition. (Howard, No.
32 at p. 1; NEMA, No. 30 at p. 3).
CDA and HVOLT commented that the reference temperature for ambient
has been used throughout the industry as 20 [ordm]C and that letting
that number float to other reference temperatures would be confusing to
industry. (CDA, No. 29 at p. 2; HVOLT, No. 27 at p. 91).
The reference temperature in the test procedure does not
necessarily refer to the ambient temperature, because testing can be
performed at a different temperature, with the results corrected to
reflect testing at the defined reference temperature. DOE did not
propose changes to any of these values for the purpose of certification
with energy conservation standards.
The updated definition does not specify particular temperature
values in order to accommodate the use of the term in a context other
than only the conditions required for certification and compliance,
i.e., voluntary representations of efficiency at temperatures or PULs
different from those specified in appendix A. For example, a
manufacturer voluntarily representing efficiency at 100 percent PUL
would correct to a reference temperature that is reflective of the
distribution transformer temperature rise at 100 percent PUL.
DOE is adopting the updated definition of ``reference temperature''
in 10 CFR 431.192 as proposed.
D. Per-Unit Load Testing Requirements
The efficiency of distribution transformers varies depending on the
PUL at which the distribution transformer is operated. DOE's energy
conservation standards for distribution transformers at 10 CFR 431.196
prescribe the PUL at which the efficiency of the distribution
transformer must be determined and certified to DOE (i.e., the
``standard PUL''). The standard PUL is intended to represent the
typical PUL experienced by in-service distribution transformers over
their lifetime. For liquid-immersed distribution transformers and
medium-voltage dry-type distribution transformers, the equipment
efficiency is certified at a standard PUL of 50 percent. For low-
voltage dry-type distribution transformers, the efficiency is certified
at a standard PUL of 35 percent. These values were adopted in the April
2006 Final Rule from NEMA TP 2-1998. 71 FR 24972.
As described previously, appendix A does not require testing of the
distribution transformer at the standard PUL; rather, the standard PUL
is required only for certification of efficiency. Testing can be
performed at any PUL, with the results mathematically adjusted to
reflect the applicable standard PUL. Section 5.1 of appendix A provides
equations to calculate the efficiency of a distribution transformer at
any PUL based on the testing of the distribution transformer at a
single PUL. Current industry practice is to test at 100 percent PUL and
mathematically determine the efficiency at the applicable standard PUL.
(NEMA, No. 30 at p. 4).
The efficiency of distribution transformers over the duration of
its lifetime and across all installations cannot be fully represented
by a single PUL. A given transformer may be highly loaded or lightly
loaded depending on its application or variation in electrical demand
throughout the day. DOE has previously acknowledged that distribution
transformers may experience a range of loading levels when installed in
the field. 78 FR 23336, 23350 (April 18, 2013).
DOE previously acknowledged that the majority of stakeholders,
including manufacturers and utilities, support retention of the current
testing requirements; and DOE determined that its existing test
procedure provides results that are representative of the performance
of distribution transformers in normal use. Id. DOE further determined
that potential improvements in testing precision that might result from
testing at multiple PULs would be outweighed by the complexity and the
burden of requiring testing at different loadings depending on each
individual transformer's characteristics. Id.
In the May 2019 NOPR, DOE stated that it had considered (1)
revising the single standard PUL \11\ to a multiple-PUL weighted-
average efficiency metric, (2) revising the single standard PUL to an
alternative single test PUL metric that better represents in-service
PUL, or (3) maintaining the current single test PUL specifications. 84
FR 20704, 20714. DOE tentatively determined that the range of in-
service PUL is diverse, and that the available information describing
in-service PUL is inconclusive. Id. DOE was unable to show that any
alternative standard PUL(s) would be more representative than the
current standard PUL and therefore did not propose an amendment of the
standard PULs. Id. DOE proposed, however, to allow for voluntary
representations to be made at PULs other than the standard PUL. Id.
---------------------------------------------------------------------------
\11\ In the May 2019 NOPR, DOE used the term ``test PUL'' to
refer to ``standard PUL'' as used in this final rule. The term
``standard PUL'' better reflects that this is referring to the PUL
at which the energy efficiency must be determined for the purpose of
complying with the energy conservation standards at 10 CFR 431.196.
As described previously in this document, testing can be performed
at any PUL, with the results corrected to the standard PUL.
---------------------------------------------------------------------------
The following sections summarize comments received on each of these
considerations, as well as DOE's responses and conclusions.
1. Multiple-PUL Weighted-Average Efficiency Metric
In the past, DOE has considered a multiple-PUL efficiency metric in
contemplating whether a weighted-average efficiency metric composed of
efficiency at more than one PUL may better reflect how distribution
transformers operate in service. 84 FR 20704, 20713. In the May 2019
NOPR, DOE expressed concern that a multi-
[[Page 51240]]
PUL metric could increase burden on manufacturers and create challenges
in consumer education without being more representative of in-service
PULs than the current metric. Id.
The Efficiency Advocates suggested that DOE request transformer
loading data from IEEE's Transformer Committee to analyze the empirical
data describing PUL variation. (Efficiency Advocates, No. 34 at p. 2)
The Efficiency Advocates, asserted that the IEEE data shows a wide
variation in PUL and that DOE should consider a weighted average PUL
efficiency metric in the DOE test procedure. (Efficiency Advocates, No.
34 at p. 2).
DOE has considered a metric based on a weighted average of a
transformer's efficiency at multiple different PULs. Different
weighting schemes are possible. For example, the measured efficiencies
could be weighted by the fraction of operating hours expected at each
PUL over the lifecycle of a distribution transformer.
Generally, distribution transformer losses are presented within the
industry as consisting of no-load losses, which are approximately
constant with PUL, and load losses, which scale nearly quadratically
with PUL. Under that set of mathematical assumptions, any particular
multi-PUL metric \12\ could alternatively be represented by a single-
PUL metric that would yield the same efficiency value. In other words,
any multi-PUL metric would be replaceable by a certain single-PUL
metric. Given this, DOE finds no advantage in adopting a multi-PUL
metric for distribution transformers. A multi-PUL metric would
represent a slightly more complex way of arriving at the same result
that could be derived from a carefully chosen single-PUL metric. As a
result, DOE is not adopting a multi-PUL metric for distribution
transformers in this final rule.
---------------------------------------------------------------------------
\12\ Specified as a set of any number of pairs of PUL values and
weighting coefficient at that PUL.
---------------------------------------------------------------------------
2. Single-PUL Efficiency Metric
As stated previously, DOE requires distribution transformers'
efficiency to be certified at a standard PUL of 50 percent for liquid-
immersed distribution transformers and medium-voltage dry-type
distribution transformers and 35 percent for low-voltage dry-type
distribution transformers. 10 CFR 431.196.
In the May 2019 NOPR, DOE stated that it had considered revising
the single standard PUL to an alternative single test PUL that better
represents in-service PUL. 84 FR 20704, 20714. DOE tentatively
determined that the range of in-service PUL values is diverse, and that
the available information describing in-service PUL is inconclusive.
Id. DOE was unable to conclude that any alternative standard PUL(s)
would be more representative than the current standard PUL and,
therefore, did not propose to amendment the standard PULs. Id.
In response to the May 2019 NOPR, DOE received comments arguing
both for and against revising the single-PUL metric; these are
discussed in detail in sections III.D.2.a and III.D.2.b. These comments
comport with the idea that distribution transformers' in-service PULs
reflect diverse operating conditions. After considering the comments
brought forward by stakeholders and discussed in sections III.D.2.a and
III.D.2.b. DOE has concluded that revising the PUL is not justified at
this time for two reasons.
First, there is significant long-term uncertainty regarding what
standard PUL would correspond to a representative average use cycle for
a distribution transformer given their long lifetimes.\13\ The publicly
available data effectively amounts to a single year from a few
distribution transformer customers. Given the uncertainty associated
with future distribution transformer loading, DOE is unable to conclude
with certainty that a given alternative single-PUL efficiency metric is
more representative than the current standard PUL.
---------------------------------------------------------------------------
\13\ DOE determined in the April 2013 ECS Final Rule as having
an average lifespan of 32 years, and in many cases they may have an
in-service lifetime that is significantly longer. 78 FR 23336,
23377.
---------------------------------------------------------------------------
Second, given the uncertainty of future loading distributions,
there may be greater risk in selecting too low a standard PUL than too
high a standard PUL for two reasons. First, the quadratic nature of
load loss means that absolute power consumption grows more quickly on
the high side of the standard PUL than on the low side. Second,
divergence of the costs associated with different categories of loss
means that there is greater risk associated with selecting too low a
standard PUL than too high.
Accordingly, in this final rule, DOE is maintaining the current
standard PUL specifications. DOE is centralizing the PUL specifications
in appendix A, as discussed in section III.F.1.
DOE considered several factors in determining not to revise the
current standard PUL requirements in this final rule. In section
III.D.2.a, DOE reviews publicly available in-service PUL data. In
sections III.D.2.b and III.D.2.c, DOE considers uncertainty in
estimates of future load growth, its effects on distribution
transformers' in-service PULs, and the respective risks associated with
both under- and overestimating actual future in-service PULs.\14\
---------------------------------------------------------------------------
\14\ See: Section 2.3 of Chapter 2. Analytical Framework,
Comments from Interested Parties, and DOE Responses of the Prelim
Technical Support Document (TSD) at Docket No. EERE-2019-BT-STD-
0018-0022.
---------------------------------------------------------------------------
a. Publicly Available Transformer Load Data
In response to the May 2019 NOPR, the Efficiency Advocates
suggested that DOE use IEEE's Advanced Meter Information (``AMI'') data
to inform the PUL rulemaking. (Efficiency Advocates, No. 34 at p. 1)
Citing IEEE's Distribution Transformer Subcommittee Task Force's
(``IEEE-TF'') estimates of average in-service PUL for medium-voltage,
liquid-filled transformers, the Efficiency Advocates suggest in-service
PULs are significantly lower than the current standard PULs.
(Efficiency Advocates, No. 34 at p. 2) The Efficiency Advocates
recommend, if DOE does not base its analysis on AMI data, that DOE use
PUL values of 35 percent for liquid-immersed transformers, 25 percent
for low-voltage dry-type distribution transformers, and 38 percent for
medium-voltage dry-type distribution transformers. (Efficiency
Advocates, No. 34, at pp. 2-3).
Cargill commented that the IEEE-TF data suggests average annual
loading is less than 30 percent of the ``Peak Annual Load''. (Cargill,
No. 28 at p. 1) Cargill stated that even in the most conservative case
of peak load equaling nameplate load, the resulting average PUL would
be less than 30 percent. (Cargill No. 28 at p. 1) NEMA commented that
it is not aware of any changes in the field that would justify
modifying the current PUL levels. (NEMA, No. 30 at p. 4).
DOE examined the data made available through IEEE-TF.\15\ All of
the data available through the IEEE-TF is for liquid-immersed
distribution transformers; DOE did not separately receive updated
loading data for LVDTs or MVDTs.
---------------------------------------------------------------------------
\15\ See: grouper.ieee.org/groups/transformers/subcommittees/distr/EnergyEfficiency/F20-DistrTransfLoading-Mulkey.pdf.
---------------------------------------------------------------------------
DOE has identified several limitations and questions regarding the
data made available through the IEEE-TF. First and foremost, none of
the datasets of AMI data referred to by the Efficiency Advocates are
measured transformer loads, rather they are samples of customer load
connected to specific transformers. Additionally, each dataset
[[Page 51241]]
presented during the IEEE-TF is a sample of customers' AMI data (i.e.,
not a complete population of distribution transformer load data), and
each carries questions regarding the sampling methodology,
representativeness, and completeness. DOE does not know what criteria
were used to select the sample from each existing population of utility
customers. Further, each data set was also incomplete in terms of
missing meter readings, non-sequential metering periods, or missing
unmetered loads (for example, exterior building lighting, utility owned
equipment, and street lighting are usually on separate unmetered
tariffs \16\). These unmetered loads, on separate unmetered tariffs,
would not be accounted for in the AMI data, and would produce the
effect of underestimating in-service PUL for a given transformer.
---------------------------------------------------------------------------
\16\ J. Triplett, S. Rinell and J. Foote, ``Evaluating
distribution system losses using data from deployed AMI and GIS
systems,'' 2010 IEEE Rural Electric Power Conference (REPC), 2010,
pp. C1-8, doi: 10.1109/REPCON.2010.5476204.
---------------------------------------------------------------------------
DOE examined the largest individual sample of data, from Dominion
Energy, Inc., which consisted of a year of hourly and sub-hourly
readings for roughly 60,000 AMI meters connected to distribution
transformers aggregated into zip codes for parts of Virginia and North
Carolina.\17\ After removing data from AMI meters that were incomplete,
or that had the quality issues highlighted in the presentation to the
IEEE-TF (loads with peak-loads that were several times higher than the
connected transformers capacity), DOE found that the average root mean
square (RMS) load, as a function of transformer nameplate capacity,
over the year in question (2018) was substantially higher than the 10
percent mode value presented to the IEEE-TF. DOE found that average RMS
in-service PUL for the transformers subject to the DOE test procedure
and energy conservation standards was 27.8 percent.\18\
---------------------------------------------------------------------------
\17\ Zip codes were used to aggregate customer AMI data to
anonymize the data.
\18\ See: Chapter 7. Energy Use Analysis of the Prelim TSD at
Docket No. EERE-2019-BT-STD-0018-0022.
---------------------------------------------------------------------------
After reviewing the IEEE-TF AMI data, DOE agrees with the
Efficiency Advocates and Cargill that the current data indicates that
the average, current, in-service, liquid-immersed distribution
transformer loading is lower than the standard PUL. However, the data
also indicates that distribution transformers operate over a diverse
range of operating conditions. The data shows that a single customer
does not operate a distribution transformer at a single constant PUL.
Further, a given distribution transformer model may be used at
different PULs by different customers. The realities of the typical
range of operations, and issues of data quality and sample completeness
raise uncertainties regarding the representativeness of the average PUL
values presented by the IEEE-TF.
DOE also notes that while the IEEE-TF AMI data provides valuable
insight into the in-service PUL of liquid-immersed distribution
transformers, no equivalent, publicly available data has been presented
for medium-voltage and low-voltage dry-type distribution transformers.
Another complicating factor in the representativeness of the
currently available data is that the IEEE-TF AMI data only covers a
single year of distribution transformer lifespans. Distribution
transformers have lifespans of several decades and as such, DOE needs
to consider not only the diversity of operating conditions that
distribution transformer currently experience but the entire range of
operating conditions a distribution transformer would experience in its
lifespan. Additionally, most of the available data are from similar
geographies, on the Atlantic coast, which would experience similar
climatic sensitivities, which is not representative of the Nation as a
whole. Stakeholders identified several possible factors that could
significantly impact distribution transformer loading in the short to
medium term, as discussed in section III.D.2.b.
b. Load Growth Uncertainties
DOE received several comments from stakeholders in response to the
May 2019 NOPR on the topic of future load growth on distribution
transformers. Cargill supported maintaining the current standard PUL,
asserting that as future transformer loads increase, increased
transformer efficiency could be realized due to conventional core steel
having a peak efficiency between 45 and 55 percent PUL. (Cargill, No.
28 at p. 1) Cargill also suggested that utilities are increasingly
considering overloading transformers during peak demand with the
objective of replacing larger mineral-oil-filled transformers with
smaller, cheaper transformers. Such an approach, Cargill asserts, could
increase average loading to 50 percent and support retaining the
current standard PULs. (Cargill, No. 28 at p. 2) The Efficiency
Advocates commented that increased adoption of photovoltaic generation
(``PV'') will depress peak demand, as it has done in California. The
Efficiency Advocates also commented that increasing adoption of
electric vehicles (``EVs'') is unlikely to contribute to peak demand
and load growth because it is in utilities' interest to encourage off-
peak charging. (Efficiency Advocates, No. 34 at p. 3) Further, the
Efficiency Advocates recommended against DOE's continued use of a 1
percent average annual increase, claiming that based on past experience
and future projections, load growth of this magnitude is unlikely.
(Efficiency Advocates, No. 34 at pp. 4) Finally, the Efficiency
Advocates asserted that increases in demand due to population growth
will be met with the installation of new transformers, rather than
increasing loads on existing transformers. (Efficiency Advocates, No.
34 at p. 2-3).
HVOLT and CDA commented that standard PUL changes are not needed
right now, but that EV charging in the future may increase loading.
(CDA, No. 29 at p. 89; HVOLT, No. 27 at p. 94).
Load growth has always been, and continues to be, difficult to
predict. Stakeholders disagreed as to what future distribution
transformer loading would be expected. While IEEE-TF data suggests that
the current in-service PUL is lower than the standard PUL, the extent
to which distribution transformer load will change over time is
unclear. Distribution transformers were evaluated in the April 2013 ECS
Final Rule as having an average lifespan of 32 years, and in many cases
they may have an in-service lifetime that is significantly longer. 78
FR 23336, 23377. The long lifetime of distribution transformers means
that many will operate through multiple economic, social, or climate-
driven events that could affect the average in-service PUL on
individual transformers.
In response to Cargill, while many conventional core steel
transformers have a peak efficiency between 45 and 55 percent, this is
not generally the case across the entire market and may in part be
driven by the 50 percent standard PUL specified in the DOE test
procedure. Given an alternative standard PUL, conventional core steel
transformers could be designed with peak efficiencies at other values.
Further, while some utilities may be considering overloading
transformers as standard operating practice and could therefore replace
larger distribution transformers with smaller distribution
transformers, thereby increasing the in-service PUL of these
distribution transformers, DOE does not have any data to substantiate
Cargill's claim that this practice is actually occurring or is expected
to occur.
In response to the Efficiency Advocates, DOE generally agrees that
PV generation as a resource at the level of the transmission grid can
both reduce
[[Page 51242]]
the overall generation required to serve a population and have
potential impacts of reducing peak-demand in areas where there is
enough solar resource to do so. However, when considered at the level
of the load(s) being served by individual distribution transformers, PV
generation (or other demand-side generation) will generally reduce the
load on the transformer only by the quantity of energy consumed on the
secondary-service side, (i.e., the customer connected side), of the
transformer. Unless the PV generation is not grid-tied, any surplus
energy being transformed from secondary-service voltages to primary-
service voltages and fed back into the grid for distribution would
contribute to the average load of the transformer. Depending on the
quantity of surplus energy being fed back into the grid, PV generation
could have the effect of either decreasing or increasing the average
PUL on an individual distribution transformer. Further, if surplus
energy is fed back into the grid during peak times, it could have the
impact of increasing both peak load and average load. A recent study by
National Renewable Energy Laboratory (``NREL'') and Los Angeles
Department of Water and Power (``LADWP''), Los Angeles 100% Renewable
Energy Study (``LA100''), researching the needs to serve the greater
city of Los Angeles with 100 percent renewable energy, estimated that
80 percent of existing distribution feeders would need to be upgraded
due to occurrences of one or more overloading violations with the
connected transformers.\19\ Integrating PV or other distributed-
generation in a dispatchable manner is a technically complex task, and
at the transmission level can reduce overall electricity demands;
however there is also the potential that loads may rise on some
distribution circuits (and connected distribution transformers) to meet
these transmission reductions.
---------------------------------------------------------------------------
\19\ Palmintier, Bryan, Meghan Mooney, Kelsey Horowitz, et al.
2021. ``Chapter 7: Distribution System Analysis.'' In the Los
Angeles 100% Renewable Energy Study, edited by Jaquelin Cochran and
Paul Denholm. Golden, CO: National Renewable Energy Laboratory.
NREL/TP-6A20-79444-7. www.nrel.gov/docs/fy21osti/79444-7.pdf.
---------------------------------------------------------------------------
The Efficiency Advocates' claim that EV impacts on peak electricity
demand and transformer loads may be small, given the assertion that it
is in the electric utility's interest to promote off-peak charging, is
incomplete. The Efficiency Advocates cited an article in support of
their assertion that ``at a macro scale, EVs appear to pose only a
modest burden on the electric grid''.\20\ However, this position
oversimplifies the relationship between connected loads, the
distribution grid, and transmission grid. The article cited by the
Energy Advocates cautions that at a micro scale, EVs represent a
significant addition to traditional household loads; and further states
that the addition of a level 2 residential EV charging station
contributes a load similar to an additional house on the grid.\21\
---------------------------------------------------------------------------
\20\ J. Coignard, P. MacDougall, F. Stadtmueller and E. Vrettos,
``Will Electric Vehicles Drive Distribution Grid Upgrades?: The Case
of California,'' in IEEE Electrification Magazine, vol. 7, no. 2,
pp. 46-56, June 2019, doi: 10.1109/MELE.2019.2908794.
\21\ Ibid.
---------------------------------------------------------------------------
While there are likely benefits to promoting off-peak charging, or
other types of structured charging schemes, EV charging is difficult to
predict and model because EV adoption is still in the early stages.
While some utility programs have been successful at shifting EV loads
from peak to off-peak times using time-of-use rates or specific EV
charging electricity tariffs, offsetting system peak capacity demands,
the additional load required to charge an EV during non-peak times will
still contribute to the overall average transformer PUL. Analysis
conducted for the LA100 study indicates, under the ``moderate''
projection, that electrical demand for transportation will be one of
the largest contributors to distribution load growth over their
analysis period (2020 through 2045).\22\ The LA100 study addresses the
load impacts on utility distribution systems, which would be served by
liquid-immersed medium-voltage distribution transformers, it does not
address the potential impacts to commercial and industrial customers
who deploy dry-type distribution transformers. The impact of EV driven
load growth on dry-type distribution transformers could also be
significant, particularly if EVs are charged on circuits without
upgrades to the serving low- or medium-voltage dry-type distribution
transformers.
---------------------------------------------------------------------------
\22\ Hale, Elaine, Anthony Fontanini, Eric Wilson, et al. 2021.
``Chapter 3: Electricity Demand Projections.'' In the Los Angeles
100% Renewable Energy Study, edited by Jaquelin Cochran and Paul
Denholm. Golden, CO: National Renewable Energy Laboratory. NREL/TP-
6A20-79444-3. www.nrel.gov/docs/fy21osti/79444-3.pdf.
---------------------------------------------------------------------------
In response to the September 2017 RFI, the Efficiency Advocates
challenged DOE's assertion that the record supports a 50 percent PUL
for liquid-immersed distribution transformers (on the basis that
increasing future load growth at the rate of one percent per-year would
result in in-service PULs that would eventually converge with the test
standard PUL over time was calculated was incorrectly). In the
September 2017 RFI DOE asserted that with a one-percent future growth
rate over time, then-current observed RMS PUL values would
approximately converge to the standard PUL values. 82 FR 44347, 44349.
In response to the load growth assertions from the Efficiency
Advocates, DOE examined the trend in sales of electricity to customers
made available by the Annual Energy Outlook (AEO) in its Electric Power
Monthly periodical.\23\ DOE first examined the time period highlighted
by the Efficiency Advocates and confirms that 2018 was a year in which
sales were much higher than in the preceding period from 2011 through
2017. DOE notes that while 2018 had the greatest year-on-year growth
over this period, there were other years with positive growth, and the
average year-on-year growth for the period between 2011 through 2018
was 0.4 percent. DOE also finds that the time period highlighted by the
Efficiency Advocates is not sufficient for this analysis given that the
average in-service lifetime for distribution transformers is 32 years.
As such, DOE takes a longer view of the trend of available data when
considering the impacts of load growth. When examining the 10-year
rolling average of year-on-year growth for the period 2010 through
2020, it can be observed that sales of electricity increased for every
period, except for the periods ending in 2017 and 2020, with an average
year-on-year increase of 0.3 percent.\24\
---------------------------------------------------------------------------
\23\ Energy Information Administration, Electric Power Monthly,
www.eia.gov/electricity/monthly/.
\24\ Energy Information Administration, {Electric Power Monthly
December 1997, DOE/EIA-0226(97/12); Electric Power Monthly December
2011, DOE/EIA-0226(2011/12); Electric Power Monthly December 2017;
Electric Power Monthly December 2020{time} , www.eia.gov/electricity/monthly/, See for each of the four listed time periods:
Table 5.1. Sales of Electricity to Ultimate Customers: Total by End-
Use Sector.
---------------------------------------------------------------------------
As mentioned, the Efficiency Advocates assert that future growth in
electricity sales will be driven by population growth, which tends to
cause grid expansion and the installation of new transformers, rather
than to increase loads on existing transformers. (Efficiency Advocates,
No. 34 at p. 2-3) DOE partially agrees with the Efficiency Advocates,
that load growth from new construction would be met with new
transformers. DOE must consider that the additional factors that drive
load growth (e.g., weather events, expanding populations, increased
electrification), impact all connected distribution transformers, not
just those installed to provide service to new construction, and
therefore must consider the effect of load growth's
[[Page 51243]]
impact on a transformer's typical use cycle.
The Efficiency Advocates requested DOE respond to their comment on
the September 2017 RFI, where the Efficiency Advocates challenged DOE's
assertion that, for liquid-immersed distribution transformers, future
load growth (at the rate of one percent per-year), would result in in-
service PULs that would eventually converge with the standard PUL over
time, and stated that the in-service PUL was calculated incorrectly.
(Efficiency Advocates, 0015 at p. 1) In the September 2017 RFI, DOE
asserted that, on average, the initial (first year) RMS PUL for liquid-
immersed transformers ranged from 34 and 40 percent for single- and
three-phase equipment, respectively, with a one percent annual increase
over the life of the transformer to account for connected load growth.
This resulted in a lifetime average PUL of 49 and 56 percent for
single- and three-phase liquid-immersed transformers, respectively. And
that it was consistent with the current test procedure requirements of
rating liquid-immersed transformers at 50 percent PUL. 86 FR 44349.
After further analysis of the data, DOE agrees with the Efficiency
Advocates that the load growth impact on PUL in the September 2017 RFI
was incorrectly calculated. DOE agrees the load growth rates needed to
support the assertion that the in-service PUL would converge with the
standards PUL over the transformers typical lifetime in the September
2017 RFI would need to be greater than the proposed one percent per-
year. While the conclusions drawn in the September 2017 RFI cannot be
supported, recent market and policy changes since the publication of
the RFI indicate that the premise that there are uncertainties and
concerns associated with future load growth, continue to be valid.
c. Risks Associated With Current and Future Losses
Given the diversity of conditions under which distribution
transformers are currently operated and the uncertainty as to how
future changes in connected loads will affect in-service PULs, DOE must
consider how a single standard PUL would fare in both circumstances in
which it overestimates and underestimates the in-service PUL. As
discussed in section III.D.1, a distribution transformer's efficiency
is determined as a function of the total losses at the standard PUL. A
distribution transformer's total losses at the standard PUL are the sum
of its no-load losses and load losses at the standard PUL. No-load
losses are approximately constant with the PUL and load losses increase
quadratically with PUL.
Every distribution transformer has a PUL for which efficiency
peaks, where no-load and load losses happen to be equal. While there is
no prescribed PUL at which this must occur, often, as a result of
optimizations in the manufacturing process, transformers are most
efficient at, or near, the DOE prescribed standard PUL. Distribution
transformers that have a peak efficiency at PUL values greater than the
average in-service PUL overemphasize load losses and distribution
transformers that have a peak efficiency less than the average in-
service PUL overemphasize no-load losses relative to transformer
designs with equivalent total losses that peak at the in-service PUL.
The asymmetry in rate of loss change--the losses rise faster at PULs
greater than the standard PUL than they fall at PULs less than the
standard PUL--contributes to the conclusion that the risk of selecting
a suboptimal standard PUL is greater on the low side than on the high
side. Efficiency falls in proportion to the degree to which in-service
PUL diverges from standard PUL. Because a lower in-service PUL
corresponds (on a single-unit basis) to a lower absolute quantity of
energy, however, a given loss of efficiency equates to a greater
absolute quantity of energy when the in-service PUL exceeds standard
PUL.\25\
---------------------------------------------------------------------------
\25\ See: Section 2.3 of Chapter 2. Analytical Framework,
Comments from Interested Parties, and DOE Responses of the Prelim
TSD at Docket No. EERE-2019-BT-STD-0018-0022.
---------------------------------------------------------------------------
As stated in section III.D.2.a, the Efficiency Advocates recommend
DOE select a lower standard PUL to better align with the AMI data.
(Efficiency Advocates, No. 34, at pp. 2-3) DOE notes that the maximum
technologically feasible design options analyzed in the April 2013
Final Rule consist of distribution transformers that have a peak
efficiency well below the standard PUL (often times below 20 percent
PUL). 78 FR 23337. This indicates that distribution transformers can be
built that perform well at both the in-service PULs cited by the
Efficiency Advocates and meet efficiency standards at the current
standard PUL. Energy savings achieved through the energy conservation
standard rulemaking at the current PUL have less of this asymmetric
risk because they do not discount load losses to the same degree as a
lower PUL.
In addition to considering the energy savings potential of the
standard PUL overestimating and underestimating in-service PUL, DOE
also considered the financial value of losses to consumers associated
with overestimating and underestimating in-service PULs.
i. Peak Coincidence Risks
The Efficiency Advocates suggested that it in the best interest of
utilities to pursue programs to mitigate risks related to peak demands.
(Efficiency Advocates, No. 34 at p. 3) Demand response programs can
help flatten peaks at the grid, distribution, and individual consumer
levels. A simplified example is a demand response program which
promotes peak-load shifting, wherein utility ratepayers defer or forego
electrical consumption during times when the system is peaking. This
may have a bottom-up effect of reducing peak power through individual
distribution transformers by reducing peak generation. Owners of
distribution transformers typically face different costs depending on
overall demand, which influences the mix of generation and storage they
may deploy to meet the demand. Large electrical consumers (who with
electrical utilities generally form the total set of distribution
transformer owners), too, face demand-based cost of electrical power.
In general, marginal cost of electricity is greater during times of
high demand. This carries implications for valuing the losses of
distribution transformers. Specifically, load losses will tend to be
costlier for the owner of the distribution transformers as
proportionally more of them occur during periods of high demand and
correspondingly higher energy cost.
By their nature, distribution transformers tend to be ``peak-
coincident'', i.e., the peak load on the distribution transformers
tends to coincide with peak load on the larger electrical network. That
distribution transformer loading peaks to when electrical power costs
peak can result in certain distribution transformer customers bearing
high operating cost for a small number of peak operating hours.
Distribution transformers designed without account of this electrical
cost dynamic, optimized for lower in-service PULs, will operate at
comparatively low efficiency when the cost of operation is greatest.
DOE recognizes that demand response programs can reduce the peak-load
impacts. However, because distribution transformers reflect the load
patterns of their connected loads, the risks of the high rate of load
losses associated with peak coincidence cannot be fully controlled by
utilities and are dependent on consumer patterns. Accordingly, DOE
needs to maintain a
[[Page 51244]]
PUL which adequately addresses both high and low in-service loads.
ii. Serving Future No-Load and Load Losses
In evaluating the financial risk to consumers of the standard PUL
over- and underestimating in-service PULs, and given the long lifespans
of distribution transformers, DOE needs to consider how future no-load
and load losses will be served.
The way in which future electricity generation needs will be met
has historically been considered in DOE's ECS analyses. However, to the
extent that the choice of metric affects the cost effectiveness and
energy consumption (both in the aggregate quantity and the timing of
that energy consumption) of consumers, some background on the power
grid (the operating site of distribution transformers) is necessary to
understand the broader impacts of any metric change. Insofar as
purchasers of distribution transformers select on the basis of first
cost, manufacturers may attempt to minimize first cost subject to
compliance with energy conservation standards. The specific
distribution transformer design that minimizes first cost may vary
based on the metric it is being evaluated against. Thus, selection of
standard PUL may indirectly influence purchase prices and energy
consumption of distribution transformers.
In the April 2013 ECS Final Rule, DOE assumed that future power
needs for no-load losses would be met by the mix of different baseline
generation types in the year of compliance, 2016. 78 FR 23337. At that
time, DOE based its analysis on the data available from AEO 2012, which
indicated a mix of generation types which was predominantly served by
coal at 26 percent, natural gas combined cycle at 19 percent,
renewables and natural gas combustion turbines both at 15 percent, with
the remainder generation being met by other generation types.\26\ DOE
projected that future no-load losses generation would be met by new
capacity from coal, as it serves predominantly base load, and natural
gas and renewables serve a mix of base-, mid-merit and peaking
loads.\27\ DOE assumed that load losses would be met with simple
combustion turbines.\28\ This resulted in a cost, in terms of dollars
per watt, ($/W) for no-load losses that was higher than the cost of
load losses. A contributing factor to this difference is the relatively
high overnight capital cost of large coal plants, in terms of dollars
per megawatt unit capacity, ($/MW) when compared to other generating
types for determining the capacity cost component of the cost of
electricity. However, the current AEO 2021 projects a very different
mix of generating fuel types, now and into the future, with retiring
coal and, to a lesser degree, nuclear generation being displaced by
natural gas, in the near-term, and then renewables in future years.
These trends are shown in Table III.3. This shift in generating fuels
suggests that the future cost associated with no-load losses and load
losses will be closer in price than previously estimated as similar
generating units are used to meet both no-load and load losses.
---------------------------------------------------------------------------
\26\ Energy Information Administration, Annual Energy Outlook,
2012, Table 54. Electric Power Projections by Electricity Market
Module Region.
\27\ See Chapter 7 of the 2013 final rule TSD, available at
https://www.regulations.gov/document/EERE-2010-BT-STD-0048-0760.
\28\ Ibid.
Table III.3--Projected Fraction of Generation by Fuel Types for Certain Years
[Percent of total generation]
--------------------------------------------------------------------------------------------------------------------------------------------------------
Year Coal (%) Natural gas (%) Nuclear (%) Renewable sources Other sources (%)
----------------------------------------------------------------------------------------------------------------- (%) \*\
2012 2021 ---------------------------------------
AEO \**\ [dagger] 2012 2021 2012 2021 2012 2021 2012 2021
--------------------------------------------------------------------------------------------------------------------------------------------------------
2010................................................ 46 ........ 23 ........ 20 ........ 10 ........ 1 ........
2015................................................ 39 ........ 26 ........ 21 ........ 13 ........ 1 ........
2020................................................ 40 20 24 40 22 20 13 20 1 0
2025................................................ 41 17 24 35 21 18 14 29 1 0
2030................................................ 40 16 25 34 21 15 13 34 1 0
2035................................................ 40 15 26 33 19 14 14 37 1 0
2040................................................ ........ 14 ........ 34 ........ 13 ........ 38 ........ 0
2045................................................ ........ 12 ........ 35 ........ 13 ........ 39 ........ 0
2050................................................ ........ 12 ........ 35 ........ 12 ........ 41 ........ 0
--------------------------------------------------------------------------------------------------------------------------------------------------------
* Includes the following generation fuel-type categories: Distributed Generation, Generation for Own Use, Petroleum, Pumped Storage/Other.
** Source: U.S. Energy Information Administration, Annual Energy Outlook 2012, Electricity Electric Power Sector Generation (Case Reference case Region
United States).
[dagger] Source: U.S. Energy Information Administration, Annual Energy Outlook 2021, Electricity Electric Power Sector Generation (Case Reference case
Region United States).
As stated previously, in this final rule, DOE is maintaining the
current standard PUL specifications. DOE is centralizing the PUL
specifications in appendix A, as discussed in section III.F.1.
Further, the test procedure and accompanying energy conservation
standards do not preclude manufacturers from optimizing distribution
transformer performance at a PUL other than the standard PUL so long as
the unit complies with the applicable standard when tested at the
standard PUL. While reducing the standard PUL could in certain cases
have a positive impact on energy savings, especially for distribution
transformers fabricated with low-loss core materials such as amorphous
steel, the same energy savings outcome can often be achieved through
amending the energy conservation standard for distribution
transformers. In other words, the savings associated with a potential
reduction of standard PUL is often a byproduct of greater consumer
selection of amorphous-based transformers, which by chance tend to both
be relatively better at smaller PUL values and also be more efficient
in absolute terms. Many of the distribution transformer designs in the
accompanying energy conservation standards preliminary engineering
analysis with efficiencies above the current standard are optimized to
operate at a PUL below 25 percent due to the use of amorphous steel
cores, while certifying at the current standard PUL. It is in the
accompanying energy conservation standards where details and data
related to the efficiency standards of distribution transformers can be
fully evaluated under the EPCA requirements that any new or amended
energy conservation standard be designed to achieve the maximum
improvement in energy or water
[[Page 51245]]
efficiency that is technologically feasible and economically justified.
(42 U.S.C. 6316(a); 42 U.S.C. 6295(o)(2)(A)) DOE is also permitting
voluntary representations of efficiency at additional PULs so that
manufacturers can communicate to customers the efficiency of their
distribution transformers at various service PULs, as discussed in
section III.D.3. Additionally, voluntarily representations at
additional PULs may be relied upon by voluntarily programs such as
ENERGY STAR[supreg], which publishes a buying guide \29\ to assist
distribution transformer purchasers that may save energy and cost in
the context of the purchasers' specific PUL distribution.
---------------------------------------------------------------------------
\29\ United States Environmental Protection Agency. ENERGY
STAR[supreg] Guide to Buying More Energy Efficient Distribution
Transformers. October 2017. Accessed July 7, 2021. https://www.energystar.gov/sites/default/files/asset/document/Transformers%20Buyer%27s%20GuideFinal10-16-17.pdf.
---------------------------------------------------------------------------
Finally, DOE notes that the observable data and trends indicate
that there are ongoing changes in policies, consumer demand, and data
availability which are beginning to have an impact on the distribution
transformer operations. These changes present uncertainties with regard
to distribution transformer loading, and DOE will continue to evaluate
changes in the market and in operation that may require consideration
in future test procedure evaluations.
3. Voluntary Representations of Efficiency at Additional PULs
In the May 2019 NOPR, DOE proposed amendments to the test procedure
to permit manufacturers to make voluntary representations of additional
performance information of distribution transformers when operated
under conditions other than those required for compliance with the
energy conservation standards for distribution transformers at 10 CFR
431.196. 84 FR 20704, 20714. DOE proposed the provisions regarding
voluntary representations to help consumers make better purchasing
decisions based on their specific installation conditions.
Specifically, DOE proposed in a new section 7 of appendix A to specify
that manufacturers are permitted to represent efficiency, no-load loss,
or load loss at additional PULs and/or reference temperatures, as long
as the equipment is also represented in accordance with DOE's test
procedure at the mandatory (standard) PUL and reference temperature.
When making voluntary representations, best practice would be for the
manufacturers also to provide the PUL and reference temperature
corresponding to those voluntary representations.
NEMA stated that the current test procedure is already applicable
to alternative PULs. (NEMA, No. 30 at p. 4) Howard, CDA, and HVOLT
commented that voluntary representations would be useful in examining
efficiencies at alternative PULs. (Howard, No. 32 at p. 1; CDA, No. 29
at p. 3; CDA, No. 29 at p. 4; HVOLT, No. 27 at p. 92-94)
As discussed, while the test procedure accommodates testing at any
PUL, and correcting the results to reflect any other specified PUL,
DOE's energy conservation standards specify standard PULs that must be
used to represent the energy efficiency of distribution transformers.
10 CFR 431.196. EPCA prohibits manufacturers from making
representations respecting the energy consumption of covered equipment
or cost of energy consumed by such equipment unless that equipment has
been tested in accordance with the applicable DOE test procedure and
such representations fairly disclose the results of that testing. (42
U.S.C. 6314(d)) Accordingly, there is benefit in manufacturers being
explicitly permitted to make representations respecting energy
consumption at alternative PULs and reference temperatures that may
better suit an individual consumer's demands.
For the reason expressed in the May 2019 NOPR and above, DOE is
establishing new section 7 of appendix A, which explicitly provides
that any PUL and temperature values other than those required for
determining compliance can be used for voluntary representations when
testing is conducted in accordance with the applicable DOE test
procedure. Table III.4 summarizes the applicable PUL and temperature
values.
Table III.4--Summary of Voluntary Representation
--------------------------------------------------------------------------------------------------------------------------------------------------------
Mandatory certified values * Voluntary representations
-----------------------------------------------------------------------------------------------------------------------
Reference
temperature Reference temperature
Metric PUL (percent) for loead loss Metric PUL (percent) ([deg]C)
([deg]C)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Liquid Immersed................. Efficiency......... 50 55 Efficiency, load Any.................. Any.
loss, no-load loss.
MVDT............................ ................... 50 75
LVDT............................ ................... 35 75
--------------------------------------------------------------------------------------------------------------------------------------------------------
* Efficiency must be determined at a reference temperature of 20 [deg]C for no-load loss for all distribution transformers.
E. Multiple Voltage Capability
Some distribution transformers have primary windings
(``primaries'') and secondary windings (``secondaries'') that may each
be reconfigured, for example either in series or in parallel, to
accommodate multiple voltages. Some configurations may be more
efficient than others.
Section 4.5.1(b) of appendix A requires that for a transformer that
has a configuration of windings that allows for more than one nominal
rated voltage, the load losses must be determined either in the winding
configuration in which the highest losses occur, or in each winding
configuration in which the transformer can operate. Similarly, section
5.0 of appendix A states that for a transformer that has a
configuration of windings that allows for more than one nominal rated
voltage, its efficiency must be determined either at the voltage at
which the highest losses occur, or at each voltage at which the
transformer is rated to operate. Under either testing and rating option
(i.e., testing only the highest loss configuration, or testing all
configurations), the winding configuration that produces the highest
losses is tested and consequently must comply with the applicable
energy conservation standard.
[[Page 51246]]
The relevant industry test standards, IEEE C57.12.00-2015 and IEEE
C57.12.01-2020, direct distribution transformers to be shipped with the
windings in series. Therefore, a manufacturer physically testing for
DOE compliance may need to disassemble the unit, reconfigure the
windings to test the configuration that produces the highest losses,
test the unit, then reassemble the unit in its original configuration
for shipping, which would add time and expense.
In the May 2019 NOPR, DOE did not propose amending the requirement
related to transformers being tested in the configuration that produces
the highest losses. 84 FR 20704, 20718. DOE noted that it provides for
certification using an alternative efficiency determination method
(AEDM), which is a mathematical model based on the transformer design
(10 CFR 429.47), and that the availability of an AEDM mitigates the
potential cost associated with having to physically test a unit in a
configuration other than in its ``as-shipped'' configuration. Id.
Howard, NEMA, CDA and HVOLT suggested that transformers be tested
in the ``as-shipped'' configuration, which is typically with the
windings in series. (Howard, No 32 at p. 1; CDA, No. 29 at p. 3; HVOLT,
No. 27 at p. 92; NEMA, No. 30 at p. 6) NEMA commented that the
requirement to test in the highest losses configuration is confusing to
customers and adds undue burden on manufacturers, whereas industry
testing standards have changed to test and ship in highest voltage
configurations. (NEMA, No. 30 at p. 6) NEMA claims the burden
associated with requiring testing of the configuration with the highest
loss is especially unnecessary given that the overwhelming majority of
transformers are used in the highest voltage configuration, with less
than 5% of transformers in applications other than the ``as-shipped''
configuration. (NEMA, No. 30 at p. 6) NEMA asserted that while it can
be hard to generalize the losses associated with less efficient winding
configurations, given the variability in application, the losses are
typically less than 1% of load losses, and that it has never seen the
difference between configurations exceed 2% of load losses. (NEMA, No.
30 at p. 4; NEMA, No. 30 at p. 6) NEMA further asserted that given the
minimal efficiency gains in testing in the highest-loss and the
relatively small percentage of transformers operated in a configuration
other than ``as-shipped'', the burden on manufacturers is not
justified. (NEMA, No. 30 at p. 6)
As stated in the May 2019 NOPR, DOE recognizes that testing in the
as-shipped condition may be less burdensome for certain manufacturers,
but DOE also stated that it does not have data to support NEMA's claim
that the ``as-shipped'' configuration would lead to a maximum of 2
percent increase in load losses. 84 FR 20704, 20718. NEMA cited certain
example distribution transformers where the load loss increase was 2
percent or less, however, the data is only for a few select
distribution transformers and not representative of the industry as a
whole. (NEMA, No. 30 at p. 7) In interviews, several manufacturers
suggested that in certain extreme cases the difference in efficiency
could be much higher than the 2 percent figure cited by NEMA.
Further, even if DOE did have data affirming the 2 percent figure
NEMA cited, it would be expected that such a change to the test
procedure would require a corresponding change to the energy
conservation standards to account for the change in measured load loss
values. A change to the energy conservation standards would necessitate
certain manufacturers of transformers with multiple windings to re-test
and re-certify their performance to DOE.
As explained in the May 2019 NOPR, as an alternative to physical
testing, DOE provides for certification using an AEDM, which is a
mathematical model based on the transformer design. 10 CFR 429.47. The
shipped configuration has no bearing on the AEDM calculation, and an
AEDM can determine the highest-loss configuration instantly. DOE notes
that most transformers are currently certified using the AEDM and the
current burden is therefore less than the commenters asserted for the
majority of manufacturers. In interviews, manufacturers suggested that
this burden existed only when verifying an AEDM. Further, many
distribution transformers are reconfigured using a switch, which
minimizes effort required to change winding configurations. NEMA
confirmed that there is no burden associated with rewiring when
utilizing an AEDM and rather that the benefit to changing to ``as-
shipped'' testing is that for higher-volume, single-phase pole mount
units manufacturers could continually gauge the ``as-shipped''
performance against the AEDM. (NEMA, Docket No. EERE-2017-BT-TP-0055-
0036 at p. 3) While there may be benefits in continually gauging the
``as-shipped'' performance against the AEDM, DOE remains concerned
about the magnitude of the increase in load losses for certain
distribution transformers.
As a result, DOE is not amending in this final rule the current
requirements of section 4.5.1(b) of appendix A (for a transformer that
has a configuration of windings that allows for more than one nominal
rated voltage, the load losses must be determined either in the winding
configuration in which the highest losses occur, or in each winding
configuration in which the transformer can operate) and section 5.0 of
appendix A (for a transformer that has a configuration of windings that
allows for more than one nominal rated voltage, its efficiency must be
determined either at the voltage at which the highest losses occur, or
at each voltage at which the transformer is rated to operate).
F. Other Test Procedure Topics
In addition to the updates to the DOE test procedure discussed in
the preceding sections, DOE also considered whether the existing test
procedure would benefit from any further revisions and/or reorganizing.
Additional issues are discussed in the following sections.
1. Per-Unit Load Specification
In the May 2019 NOPR, DOE proposed to centralize the PUL
specifications, both for the certification to energy conservation
standards and for use with a voluntary representation. 84 FR 20704,
20718-20719. Currently, the PULs required for certification to energy
conservation standards are specified for each class of distribution
transformer at 10 CFR 431.196 and referenced indirectly in multiple
locations, including 10 CFR 431.192 (within the definition of reference
temperature), section 3.5(a) of appendix A, and section 5.1 of appendix
A. DOE proposed to consolidate the PUL specification into one
location--a newly proposed section 2.1 of appendix A. Additionally, DOE
proposed to provide in the proposed section 2.1 of appendix A that the
PUL specification can be any value for purposes of voluntary
representations. Id. DOE did not receive any comments on these proposed
changes and is adopting them in this final rule.
The consolidation enhances readability of the test procedure and
more clearly communicates the PUL requirements with respect to
certification to energy conservation standards and voluntary
representations. The updates do not change the standard PUL
requirements with respect to certification to energy conservation
standards. Instead, the updates improve clarity with respect to
selection of PUL for voluntary
[[Page 51247]]
representations versus certification to energy conservation standards.
DOE also proposed editorial changes to section 5.1 of appendix A to
support the consolidated approach to PUL specification. 84 FR 20704,
20719. Section 5.1 of appendix A provides equations used to calculate
load-losses at any PUL. Section 5.1 of appendix A used language that
limited its applicability to certification to energy conservation
standards only. For example, it referenced the ``specified energy
efficiency load level'' (i.e., the PUL required for certification to
energy conservation standards) specifically. DOE proposed to generalize
the language in this section to reference the PUL selected in the
proposed section 2.1. Id.
DOE did not receive any comments regarding these proposed editorial
changes and is adopting them in this final rule.
2. Reference Temperature Specification
Similar to PUL, DOE proposed to consolidate the reference
temperature specifications for certification to energy conservation
standards and for the proposed voluntary representations. 84 FR 20704,
20719. The reference temperature specifications for certification to
energy conservation standards are defined at 10 CFR 431.192 (as the
definition of ``reference temperature''), and are referenced in section
3.5(a) of appendix A and section 4.4.3.3 of appendix A. DOE proposed to
consolidate the reference temperature specifications into one
location--a newly proposed section 2.2 of appendix A. 84 FR 20704,
20719. Additionally, DOE proposed to describe in the proposed section
2.2 of appendix A that the reference temperature specification can be
any value for purposes of voluntary representations. Id. DOE did not
receive any comments on the proposed changes and is adopting them in
this final rule.
Similar to PUL, this consolidation will enhance readability of the
test procedure and more clearly communicate DOE's reference temperature
requirements with respect to certification to energy conservation
standards or voluntary representations. The updates do not change
existing reference temperature requirements with respect to
certification to energy conservation standards. Instead, the updates
improve clarity with respect to selection of reference temperature for
voluntary representations versus certification to energy conservation
standards.
DOE also proposed editorial changes to sections 3.5 and 4.4.3.3 of
appendix A to support the consolidated approach to reference
temperature specification. Section 3.5 of appendix A provided reference
temperatures for certification to energy conservation standards. DOE
has consolidated reference temperature specifications into one location
(section 2.2); therefore, DOE has removed the same specification in
section 3.5 so that the section is applicable to determine voluntary
representations.
Section 4.4.3.3 of appendix A provides the specifications and
equations used for correcting no-load loss to the reference
temperature. Specifically, the section provides an option for no
correction if the no-load measurements were made between 10 [deg]C and
30 [deg]C (representing a 10 [deg]C tolerance around the 20
[deg]C reference temperature). This tolerance is applicable only for
certification to energy conservation standards. For simplicity, DOE
proposed no such tolerance for voluntary representations at additional
reference temperatures, so that all measured values would be adjusted
using the reference temperature correction formula. 84 FR 20704, 20719.
Finally, DOE proposed to remove any reference to a reference
temperature of 20 [deg]C so that the section would be applicable to
determine voluntary representations. Id.
DOE did not receive any comments on these proposed changes and is
adopting them in this final rule.
3. Measurement Location
DOE proposed to specify that load and no-load loss measurements are
required to be taken only at the transformer terminals. 84 FR 20704,
20719. In the May 2019 NOPR, DOE proposed a definition for
``terminal,'' as described in section III.C.2.b of this final rule. DOE
notes that section 5.4 of IEEE.C57.12.90-2015 and section 5.6 of IEEE
C57.12.91-2020 specify terminal-based load-loss measurements. In
addition, section 8.2.4 of IEEE.C57.12.90-2015 and section 8.2.5 of
IEEE C57.12.91-2020 provide the same for no-load loss measurement.
These documents reflect current industry practices and manufacturers
are already measuring losses at the transformer terminals. Therefore,
DOE proposed to specify in section 4.3(c) of appendix A that both load
loss and no-load loss measurements must be made from terminal to
terminal. 84 FR 20704, 20719.
DOE received no comments in response to this proposal and is
adopting it in this final rule.
4. Specification for Stabilization of Current and Voltage
Section 3.3.2 and 3.3.1 of appendix A describe a voltmeter-ammeter
method and resistance bridge methods, respectively, for measuring
resistance. Both methods require measurements to be stable before
determining the resistance of the transformer winding being measured.
Specifically, the voltmeter-ammeter method in section 3.3.2(b) of
appendix A requires that current and voltage readings be stable before
taking simultaneous readings of current and voltage to determine
winding resistance. For the resistance bridge methods, section 3.3.1 of
appendix A requires the bridge to be balanced (i.e., no voltage across
it or current through it) before determining winding resistance. Both
methods allow for a resistor to reduce the time constant of the
circuit, but do not explicitly specify how to determine when
measurements are stable. DOE notes that IEEE C57.12.90-2015, IEEE
C57.12.91-2020, IEEE C57.12.00-2015, and IEEE C57.12.01-2020 do not
specify how to determine that stabilization is reached. Section 3.4.2
of appendix A provides related instruction for improving measurement
accuracy of resistance by reducing the transformer's time constant.
However, section 3.4.2 also does not explicitly provide for the period
of time (such as a certain multiple of the time constant) necessary to
achieve stability. In the May 2019 NOPR, DOE requested comment on how
industry currently determines that measurements have stabilized before
determining winding resistance using both voltmeter-ammeter method and
resistance bridge methods. 84 FR 20704, 20719.
NEMA commented that testing is typically done with a computer/
electronic automatic test system where the feature is provided. NEMA
stated that its members have not used a resistance bridge method in 20
years. (NEMA, No. 30 at p. 4) HVOLT and CDA commented that both the
resistance bridge and voltmeter-ammeter methods should be accurate as
long as four-time constants have passed. (HVOLT, No. 27 at p. 93; CDA,
No. 29 at p. 3)
Commenters have not suggested that there is an issue with the
accuracy of measurements associated with achieving sufficient stability
and did not suggest that DOE needed to explicitly provide for the
period of time necessary to achieve stability. Therefore, DOE has not
adopted any amendments related to the period of time to achieve
stability.
[[Page 51248]]
5. Ambient Temperature Tolerances
In response to the September 2017 RFI, NEMA recommended that DOE
increase the ambient temperature tolerances for testing dry-type
transformers, stating that testing may otherwise be burdensome in
laboratories that are not climate controlled, and that a mathematical
correction factor could be developed as an alternative to the
temperature limits. (NEMA, Docket No. EERE-2017-BT-0055-0014 at p. 2)
In the May 2019 NOPR, DOE explained that while widening the
tolerances of temperatures (or other measured parameters) may reduce
testing cost, it may impact the reproducibility and repeatability of
the test result. 84 FR 20704, 20719-20720. Further, NEMA acknowledged
that manufacturers are not having difficulty meeting the temperature
requirement. (NEMA, Docket No. EERE-2017-BT-0055-0014 at p. 8)
DOE does not have data regarding typical ranges of laboratory
ambient temperature and, as a result, cannot be certain that reduction
in temperature tolerance would not impact reproducibility,
repeatability, and accuracy and cause future test results to become
incomparable to past data. For these reasons, DOE did not propose
amendments to the laboratory ambient temperature and transformer
internal temperature requirements in the May 2019 NOPR. 84 FR 20704,
20720.
Comments received on this issue supported maintaining the current
ambient temperature tolerances. (Howard, No. 31 at p. 1; NEMA, No. 30
at p. 4; CDA, No. 29 at p. 3; HVOLT, No. 27 at p. 93) For the reasons
discussed in the May 2019 NOPR and in the preceding paragraph, DOE is
maintaining the ambient temperature requirements in appendix A.
6. Harmonic Current
Harmonic current refers to electrical power at alternating current
frequencies greater than the fundamental frequency. Distribution
transformers in service are commonly subject to (and must tolerate)
harmonic current of a degree that varies by application. Sections
4.4.1(a) and 4.4.3.2(a) of appendix A direct use of a sinusoidal
waveform for evaluating efficiency in distribution transformers.
DOE recognizes that transformers in service are subject to a
variety of harmonic conditions, and that the test procedure must
provide a common basis for comparison. Currently, the test procedure
states that transformers designed for harmonic currents must be tested
with a sinusoidal waveform (i.e., free of harmonic current), but does
not do so for all other varieties of transformers. However, the intent
of the test procedure is for all transformers to be tested with a
sinusoidal waveform, as is implicit in section 4.4.1(a) of appendix A.
To clarify this test setup requirement, DOE proposed to modify section
4.1 of appendix A to read ``. . . Test all distribution transformers
using a sinusoidal waveform (k=1).'' 84 FR 20704, 20720 This is
consistent with industry practice and manufacturers are already testing
all distribution transformers using a sinusoidal waveform. Id.
DOE received several comments in support of this clarification and
none in opposition. (Howard, No. 32 at p. 2; NEMA, No. 30 at p. 4; CDA,
No. 29 at p. 3; HVOLT, No. 27 at p. 93) For the reasons discussed in
the May 2019 NOPR and in the preceding paragraph, DOE is adopting the
clarification regarding use of a sinusoidal waveform as proposed.
7. Other Editorial Revisions
In the May 2019 NOPR, DOE proposed the following editorial updates
to improve the readability of the test procedure and provide additional
detail: (i) Revising ``shall'' (and a single instance of ``should'' in
the temperature condition requirements at section 3.2.2(b)(3)) to
``must'' throughout appendix A, (ii) clarifying the instructional
language for recording the winding temperature for dry-type
transformers (section 3.2.2 of appendix A), (iii) separating certain
sentences into enumerated clauses (section 3.2.2(a) of appendix A),\30\
(iv) identifying the corresponding resistance measurement method
sections (section 3.3 of appendix A), (v) replacing a reference to
``uniform test method'' with ``this appendix'' (section 3.3 of appendix
A), (vi) removing reference to guidelines under section 3.4.1, Required
actions, of appendix A to clarify that section establishes
requirements, (vii) specifying the maximum amount of time for the
temperature of the transformer windings to stabilize (section
3.2.2(b)(4) of appendix A \31\), (viii) removing references to the test
procedure in 10 CFR 431.196, and (ix) replacing any reference to
accuracy requirements in ``section 2.0'' and/or ``Table 2.0'' to
``section 2.3'' and/or ``Table 2.3,'' accordingly. 84 FR 20704, 20720.
---------------------------------------------------------------------------
\30\ Under the changes adopted in this document, section
3.2.2(a) of appendix A is split into section 3.2.2(a) and section
3.2.2(b).
\31\ Under the changes adopted in this document, this section is
redesignated as section 3.2.2(c)(4) of appendix A.
---------------------------------------------------------------------------
Section 3.2.2 of appendix A requires that, for testing of both
ventilated and sealed units, the ambient temperature of the test area
may be used to estimate the winding temperature (rather than direct
measurement of the winding temperature), provided a number of
conditions are met, including the condition that neither voltage nor
current has been applied to the unit under test for 24 hours (provided
in section 3.2.2(b)(4) of appendix A). The same section also allows for
the time period of the initial 24 hours to be increased to up to a
maximum of an additional 24 hours, so as to allow the temperature of
the transformer windings to stabilize at the level of the ambient
temperature. Based on this requirement, the total amount of time
allowed would be a maximum of 48 hours. As such, in the May 2019 NOPR,
DOE proposed to specify explicitly that, for section 3.2.2(b)(4) of
appendix A, the total maximum amount of time allowed is 48 hours. Id.
DOE also proposed conforming amendments to the energy conservation
standard provisions. The provisions in 10 CFR 431.196 establishes
energy conservation standards for certain distribution transformers.
Id. Immediately following each table of standards, a note specifies the
applicable standard PUL and DOE test procedure. For example, in 10 CFR
431.196(a) the note reads, ``Note: All efficiency values are at 35
percent of nameplate-rated load, determined according to the DOE Test
Method for Measuring the Energy Consumption of Distribution
Transformers under appendix A to subpart K of 10 CFR part 431.''
Because 10 CFR 431.193 already requires that testing be in accordance
with appendix A, DOE proposes to remove the references to the test
procedure in 10 CFR 431.196. DOE proposes to maintain the portion of
the note identifying the PUL corresponding to the efficiency values,
for continuity and clarity. Id.
As discussed in sections III.F.1 and III.F.2 of this final rule,
DOE is clarifying the PUL and reference temperature specifications for
certification to energy conservation standards, and providing PUL and
reference temperature specifications for voluntary representations,
with a new section 2.1 for PUL requirements and section 2.2 for
reference temperature requirements in appendix A. Accordingly, DOE
proposed that the accuracy requirements previously provided in section
2.0 be moved to section 2.3 in appendix A. In addition, DOE proposed to
re-number Table 2.1, Test System Accuracy Requirements for Each
Measured Quantity, to Table 2.3. Lastly, DOE proposed to update cross-
[[Page 51249]]
references in appendix A to the accuracy requirements in section 2.0
and/or Table 2.1, to section 2.3 and/or Table 2.3. The cross-references
occur in sections 3.1(b), 3.3.3, 3.4.2(a), 4.3(a), 6.0, and 6.2 of
appendix A.
DOE did not receive any comment in opposition to these edits and is
adopting them in the test procedure.
NEMA noted certain errors in the equation references in section 4
of appendix A. (NEMA, No. 30 at p. 5) Specifically, NEMA stated that
the load loss power (Plc1) appears with subscripts ``LCL'',
``LCI'', and ``LC1'' (capital letters used for clarity, but lower case
used in the text). Id. DOE has reviewed the subscripts in section 4 of
appendix A and corrected each instance to ``LC1'' (capitalized here for
clarity) where necessary.
NEMA also noted that there is potential confusion regarding which
reference temperature should be used in section 4.5.3.3 of appendix A.
NEMA suggested to clarify the text as follows: ``When the measurement
of load loss is made at a temperature Tim that is different
from the reference temperature, use the procedure summarized in the
equations 4-6 to 4-10 to correct the measured load loss to the
reference temperature (as defined in 3.5 (a)).'' (NEMA, No. 30 at p. 5-
6) This final rule includes a new section, section 2.2 of appendix A,
to specify reference temperature in a centralized location, as
described in section III.F.2 of this document. In view of the new
requirement, NEMA's suggested edits to specify reference temperature in
section 4.5.3.3 are redundant.
PG&E commented in response to the May 2019 NOPR that in order to
properly comment, it would like a before and after document of proposed
changes to the CFR. (PG&E, No. 33 at p. 1) The May 2019 NOPR includes a
synopsis table of the proposed changes, including a side-by-side
comparison of the current DOE TP language, the proposed test procedure
language, and attribution of the changes. 84 FR 20704, 20706. Further,
DOE published all proposed regulatory text in the May 2019 NOPR which
could be juxtaposed with the current CFR in order to perform the
comparison PG&E describes. 84 FR 20704, 20727-20730.
G. Effective and Compliance Dates
The effective date for the adopted test procedure amendment is 30
days after publication of this final rule in the Federal Register. EPCA
prescribes that all representations of energy efficiency and energy
use, including those made on marketing materials and product labels,
must be made in accordance with an amended test procedure, beginning
180 days after publication of the final rule in the Federal Register.
(42 U.S.C. 6293(c)(2); 42 U.S.C. 6314(d)(1)) EPCA provides an allowance
for individual manufacturers to petition DOE for an extension of the
180-day period if the manufacturer may experience undue hardship in
meeting the deadline. (42 U.S.C. 6293(c)(3); 42 U.S.C. 6314(d)(2)) To
receive such an extension, petitions must be filed with DOE no later
than 60 days before the end of the 180-day period and must detail how
the manufacturer will experience undue hardship. (Id.)
H. Test Procedure Costs
In this final rule, DOE is amending the existing test procedure for
distribution transformers by revising certain definitions,
incorporating new definitions, incorporating revisions based on the
latest versions of the IEEE industry testing standards, including
provisions to allow manufacturers to use the DOE test procedure to make
voluntary representations at additional PULs and/or reference
temperatures, and reorganizing content among relevant sections of the
CFR to improve readability. The adopted amendments primarily provide
updates and supplemental details for how to conduct the test procedure
and do not add complexity to test conditions/setup or add test steps.
In accordance with EPCA, DOE has determined that these adopted
amendments will not be unduly burdensome for manufacturers to conduct.
Further, DOE has determined that the adopted test procedure amendments
will not impact testing costs already experienced by manufacturers. DOE
estimated, based on a test quote from a laboratory, that the cost for
testing distribution transformers using the existing test procedure is
approximately $400 per unit tested and that this figure will not change
in response to the adopted test procedure amendments. In summary, the
adopted test procedure amendments reflect and codify current industry
practice.
As previously described in the May 2019 NOPR, the adopted
amendments will not impact the scope of the test procedure. The adopted
amendments will not require the testing of distribution transformers
not already subject to the test procedure at 10 CFR 431.193 (i.e., the
adopted amendments will not require manufacturers to test
autotransformers, drive (isolation) transformers, grounding
transformers, machine-tool (control) transformers, nonventilated
transformers, rectifier transformers, regulating transformers, sealed
transformer; special-impedance transformer; testing transformer;
transformer with tap range of 20 percent or more; uninterruptible power
supply transformer; or welding transformer, which are presently not
subject to testing). The adopted amendments will not alter the measured
energy efficiency or energy use of the distribution transformers.
Manufacturers will be able to rely on data generated under the current
test procedure. Further, the adopted amendments will not require the
purchase of additional equipment for testing.
In the May 2019 NOPR, DOE described why the proposed test procedure
amendments would not add costs to manufacturers. In response,
manufacturers commented stating the proposed testing should not
increase testing costs for any manufacturers. (Howard, No. 32 at p. 2;
CDA, No. 29 at p. 3-4; HVOLT, No. 27 at p. 91-93) NEMA commented that
it does not anticipate any negative impact or increased costs
associated with any of the proposed changes but stressed that DOE
continue to allow manufacturers to certify distribution transformers
using an AEDM as is allowed at 10 CFR 429.70(d) in order to minimize
testing costs. (NEMA, No. 30 at p. 4) DOE notes that it has not
proposed or adopted any changes to 10 CFR 429.70(d), and manufacturers
are permitted to use an AEDM for means of certifying distribution
transformer efficiency to DOE.
IV. Procedural Issues and Regulatory Review
A. Review Under Executive Order 12866
The Office of Management and Budget (``OMB'') has determined this
test procedure rulemaking does not constitute a ``significant
regulatory action'' under section 3(f) of Executive Order (``E.O.'')
12866, Regulatory Planning and Review, 58 FR 51735 (Oct. 4, 1993).
Accordingly, this action was not subject to review under the Executive
order by the Office of Information and Regulatory Affairs (``OIRA'') in
OMB.
B. Review Under the Regulatory Flexibility Act
The Regulatory Flexibility Act (5 U.S.C. 601 et seq.) requires
preparation of a final regulatory flexibility analysis (``FRFA'') for
any final rule where the agency was first required by law to publish a
proposed rule for public comment, unless the agency certifies that the
rule, if promulgated, will not have a significant economic impact on a
substantial number of small entities. As required by Executive Order
13272,
[[Page 51250]]
``Proper Consideration of Small Entities in Agency Rulemaking,'' 67 FR
53461 (August 16, 2002), DOE published procedures and policies on
February 19, 2003 to ensure that the potential impacts of its rules on
small entities are properly considered during the DOE rulemaking
process. 68 FR 7990. DOE has made its procedures and policies available
on the Office of the General Counsel's website: https://energy.gov/gc/office-general-counsel.
As stated, the amendments adopted in this final rule revise certain
definitions, incorporate new definitions, incorporate revisions based
on the latest versions of the IEEE industry testing standards, include
provisions to allow manufacturers to use the DOE test procedure to make
voluntary representations at additional PULs and/or reference
temperatures, and reorganize content among relevant sections of the CFR
to improve readability. DOE has determined that the adopted test
procedure amendments would not impact testing costs already experienced
by manufacturers. NEMA, CDA, and HVOLT commented that they do not
anticipate any undue burden on small businesses or small manufacturers.
(NEMA, No. 30 at p. 5; CDA, No. 29 at p. 4; HVOLT, No. 27 at p. 94)
Therefore, DOE concludes that the cost effects accruing from the
final rule would not have a ``significant economic impact on a
substantial number of small entities,'' and that the preparation of a
FRFA is not warranted. DOE has submitted a certification and supporting
statement of factual basis to the Chief Counsel for Advocacy of the
Small Business Administration for review under 5 U.S.C. 605(b).
C. Review Under the Paperwork Reduction Act of 1995
Manufacturers of distribution transformers must certify to DOE that
their products comply with any applicable energy conservation
standards. To certify compliance, manufacturers must first obtain test
data for their products according to the DOE test procedure, including
any amendments adopted for that test procedure. DOE has established
regulations for the certification and recordkeeping requirements for
all covered consumer products and commercial equipment, including
distribution transformers. (See generally 10 CFR part 429.) The
collection-of-information requirement for the certification and
recordkeeping is subject to review and approval by OMB under the
Paperwork Reduction Act (PRA). This requirement has been approved by
OMB under OMB control number 1910-1400. Public reporting burden for the
certification is estimated to average 35 hours per response, including
the time for reviewing instructions, searching existing data sources,
gathering and maintaining the data needed, and completing and reviewing
the collection of information.
The amendments adopted in this final rule do not impact the
certification and reporting requirements for distribution transformers.
Notwithstanding any other provision of the law, no person is
required to respond to, nor shall any person be subject to a penalty
for failure to comply with, a collection of information subject to the
requirements of the PRA, unless that collection of information displays
a currently valid OMB Control Number.
D. Review Under the National Environmental Policy Act of 1969
Pursuant to the National Environmental Policy Act of 1969
(``NEPA''), DOE has analyzed this action in accordance with NEPA and
DOE's NEPA implementing regulations (10 CFR part 1021). DOE has
determined that this rule qualifies for categorical exclusion under 10
CFR part 1021, subpart D, appendix A5, because it is an interpretive
rulemaking that does not change the environmental effect of the rule
and meets the requirements for application of a CX. See 10 CFR
1021.410. Therefore, DOE has determined that promulgation of this rule
is not a major Federal action significantly affecting the quality of
the human environment within the meaning of NEPA and does not require
an EA or EIS.
E. Review Under Executive Order 13132
Executive Order 13132, ``Federalism,'' 64 FR 43255 (August 4,
1999), imposes certain requirements on agencies formulating and
implementing policies or regulations that preempt State law or that
have federalism implications. The Executive order requires agencies to
examine the constitutional and statutory authority supporting any
action that would limit the policymaking discretion of the States and
to carefully assess the necessity for such actions. The Executive order
also requires agencies to have an accountable process to ensure
meaningful and timely input by State and local officials in the
development of regulatory policies that have federalism implications.
On March 14, 2000, DOE published a statement of policy describing the
intergovernmental consultation process it will follow in the
development of such regulations. 65 FR 13735. DOE examined this final
rule and determined that it will not have a substantial direct effect
on the States, on the relationship between the National Government and
the States, or on the distribution of power and responsibilities among
the various levels of government. EPCA governs and prescribes Federal
preemption of State regulations as to energy conservation for the
products that are the subject of this final rule. States can petition
DOE for exemption from such preemption to the extent, and based on
criteria, set forth in EPCA. (42 U.S.C. 6297(d)) No further action is
required by Executive Order 13132.
F. Review Under Executive Order 12988
Regarding the review of existing regulations and the promulgation
of new regulations, section 3(a) of Executive Order 12988, ``Civil
Justice Reform,'' 61 FR 4729 (Feb. 7, 1996), imposes on Federal
agencies the general duty to adhere to the following requirements: (1)
Eliminate drafting errors and ambiguity; (2) write regulations to
minimize litigation; (3) provide a clear legal standard for affected
conduct rather than a general standard; and (4) promote simplification
and burden reduction. Section 3(b) of Executive Order 12988
specifically requires that executive agencies make every reasonable
effort to ensure that the regulation (1) clearly specifies the
preemptive effect, if any; (2) clearly specifies any effect on existing
Federal law or regulation; (3) provides a clear legal standard for
affected conduct while promoting simplification and burden reduction;
(4) specifies the retroactive effect, if any; (5) adequately defines
key terms; and (6) addresses other important issues affecting clarity
and general draftsmanship under any guidelines issued by the Attorney
General. Section 3(c) of Executive Order 12988 requires executive
agencies to review regulations in light of applicable standards in
sections 3(a) and 3(b) to determine whether they are met, or it is
unreasonable to meet one or more of them. DOE has completed the
required review and determined that, to the extent permitted by law,
this final rule meets the relevant standards of Executive Order 12988.
G. Review Under the Unfunded Mandates Reform Act of 1995
Title II of the Unfunded Mandates Reform Act of 1995 (``UMRA'')
requires each Federal agency to assess the effects of Federal
regulatory actions on State, local, and Tribal governments, and the
private sector. Public Law 104-4, sec. 201 (codified at 2 U.S.C. 1531).
For a regulatory action resulting in a rule that
[[Page 51251]]
may cause the expenditure by State, local, and Tribal governments, in
the aggregate, or by the private sector of $100 million or more in any
one year (adjusted annually for inflation), section 202 of UMRA
requires a Federal agency to publish a written statement that estimates
the resulting costs, benefits, and other effects on the national
economy. (2 U.S.C. 1532(a), (b)) The UMRA also requires a Federal
agency to develop an effective process to permit timely input by
elected officers of State, local, and Tribal governments on a proposed
``significant intergovernmental mandate,'' and requires an agency plan
for giving notice and opportunity for timely input to potentially
affected small governments before establishing any requirements that
might significantly or uniquely affect small governments. On March 18,
1997, DOE published a statement of policy on its process for
intergovernmental consultation under UMRA. 62 FR 12820; also available
at https://energy.gov/gc/office-general-counsel. DOE examined this
final rule according to UMRA and its statement of policy and determined
that the rule contains neither an intergovernmental mandate, nor a
mandate that may result in the expenditure of $100 million or more in
any year, so these requirements do not apply.
H. Review Under the Treasury and General Government Appropriations Act,
1999
Section 654 of the Treasury and General Government Appropriations
Act, 1999 (Pub. L. 105-277) requires Federal agencies to issue a Family
Policymaking Assessment for any rule that may affect family well-being.
This final rule will not have any impact on the autonomy or integrity
of the family as an institution. Accordingly, DOE has concluded that it
is not necessary to prepare a Family Policymaking Assessment.
I. Review Under Executive Order 12630
DOE has determined, under Executive Order 12630, ``Governmental
Actions and Interference with Constitutionally Protected Property
Rights'' 53 FR 8859 (March 18, 1988), that this regulation will not
result in any takings that might require compensation under the Fifth
Amendment to the U.S. Constitution.
J. Review Under Treasury and General Government Appropriations Act,
2001
Section 515 of the Treasury and General Government Appropriations
Act, 2001 (44 U.S.C. 3516 note) provides for agencies to review most
disseminations of information to the public under guidelines
established by each agency pursuant to general guidelines issued by
OMB. OMB's guidelines were published at 67 FR 8452 (Feb. 22, 2002), and
DOE's guidelines were published at 67 FR 62446 (Oct. 7, 2002). Pursuant
to OMB Memorandum M-19-15, Improving Implementation of the Information
Quality Act (April 24, 2019), DOE published updated guidelines which
are available at www.energy.gov/sites/prod/files/2019/12/f70/DOE%20Final%20Updated%20IQA%20Guidelines%20Dec%202019.pdf. DOE has
reviewed this final rule under the OMB and DOE guidelines and has
concluded that it is consistent with applicable policies in those
guidelines.
K. Review Under Executive Order 13211
Executive Order 13211, ``Actions Concerning Regulations That
Significantly Affect Energy Supply, Distribution, or Use,'' 66 FR 28355
(May 22, 2001), requires Federal agencies to prepare and submit to OMB,
a Statement of Energy Effects for any significant energy action. A
``significant energy action'' is defined as any action by an agency
that promulgated or is expected to lead to promulgation of a final
rule, and that (1) is a significant regulatory action under Executive
Order 12866, or any successor order; and (2) is likely to have a
significant adverse effect on the supply, distribution, or use of
energy; or (3) is designated by the Administrator of OIRA as a
significant energy action. For any significant energy action, the
agency must give a detailed statement of any adverse effects on energy
supply, distribution, or use if the regulation is implemented, and of
reasonable alternatives to the action and their expected benefits on
energy supply, distribution, and use.
This regulatory action is not a significant regulatory action under
Executive Order 12866. Moreover, it would not have a significant
adverse effect on the supply, distribution, or use of energy, nor has
it been designated as a significant energy action by the Administrator
of OIRA. Therefore, it is not a significant energy action, and,
accordingly, DOE has not prepared a Statement of Energy Effects.
L. Review Under Section 32 of the Federal Energy Administration Act of
1974
Under section 301 of the Department of Energy Organization Act
(Pub. L. 95-91; 42 U.S.C. 7101), DOE must comply with section 32 of the
Federal Energy Administration Act of 1974, as amended by the Federal
Energy Administration Authorization Act of 1977. (15 U.S.C. 788;
``FEAA'') Section 32 essentially provides in relevant part that, where
a proposed rule authorizes or requires use of commercial standards, the
notice of proposed rulemaking must inform the public of the use and
background of such standards. In addition, section 32(c) requires DOE
to consult with the Attorney General and the Chairman of the Federal
Trade Commission (``FTC'') concerning the impact of the commercial or
industry testing standards on competition.
The modifications to the test procedure for distribution
transformers adopted in this final rule do not incorporate testing
methods contained in commercial standards. Therefore, the requirements
of section 32(b) of the FEAA do not apply.
M. Congressional Notification
As required by 5 U.S.C. 801, DOE will report to Congress on the
promulgation of this rule before its effective date. The report will
state that it has been determined that the rule is not a ``major rule''
as defined by 5 U.S.C. 804(2).
V. Approval of the Office of the Secretary
The Secretary of Energy has approved publication of this final
rule.
List of Subjects in 10 CFR Part 431
Administrative practice and procedure, Confidential business
information, Energy conservation test procedures, and Reporting and
recordkeeping requirements.
Signing Authority
This document of the Department of Energy was signed on September
2, 2021, by Kelly Speakes-Backman, Principal Deputy Assistant Secretary
and Acting Assistant Secretary for Energy Efficiency and Renewable
Energy, pursuant to delegated authority from the Secretary of Energy.
That document with the original signature and date is maintained by
DOE. For administrative purposes only, and in compliance with
requirements of the
[[Page 51252]]
Office of the Federal Register, the undersigned DOE Federal Register
Liaison Officer has been authorized to sign and submit the document in
electronic format for publication, as an official document of the
Department of Energy. This administrative process in no way alters the
legal effect of this document upon publication in the Federal Register.
Signed in Washington, DC, on September 2, 2021.
Treena V. Garrett,
Federal Register Liaison Officer, U.S. Department of Energy.
For the reasons stated in the preamble, DOE amends part 431 of
chapter II of title 10, Code of Federal Regulations as set forth below:
PART 431--ENERGY EFFICIENCY PROGRAM FOR CERTAIN COMMERCIAL AND
INDUSTRIAL EQUIPMENT
0
1. The authority citation for part 431 continues to read as follows:
Authority: 42 U.S.C. 6291-6317; 28 U.S.C. 2461 note.
0
2. Section 431.192 is amended by:
0
a. Adding in alphabetical order the definition for Auxiliary device;
0
b. Revising the definition of Low-voltage dry-type distribution
transformer;
0
c. Adding in alphabetical order the definition for Per-unit load;
0
d. Revising the definition of Reference temperature; and
0
e. Adding in alphabetical order the definition for Terminal.
The additions and revisions read as follows:
Sec. 431.192 Definitions.
* * * * *
Auxiliary device means a localized component of a distribution
transformer that is a circuit breaker, switch, fuse, or surge/lightning
arrester.
* * * * *
Low-voltage dry-type distribution transformer means a distribution
transformer that has an input voltage of 600 volts or less and has the
core and coil assembly immersed in a gaseous or dry-compound insulating
medium.
* * * * *
Per-unit load means the fraction of rated load.
* * * * *
Reference temperature means the temperature at which the
transformer losses are determined, and to which such losses are
corrected if testing is done at a different point. (Reference
temperature values are specified in the test method in appendix A to
this subpart.)
* * * * *
Terminal means a conducting element of a distribution transformer
providing electrical connection to an external conductor that is not
part of the transformer.
* * * * *
0
3. Section 431.193 is revised to read as follows:
Sec. 431.193 Test procedure for measuring energy consumption of
distribution transformers.
The test procedure for measuring the energy efficiency of
distribution transformers for purposes of EPCA is specified in appendix
A to this subpart. The test procedure specified in appendix A to this
subpart applies only to distribution transformers subject to energy
conservation standards at Sec. 431.196.
0
4. Section 431.196 is amended by revising the Notes in paragraphs
(a)(1) and (2), (b)(1) and (2), and (c)(1) and (2) to read as follows:
Sec. 431.196 Energy conservation standards and their effective dates.
(a) * * *
(1) * * *
Note 1 to paragraph (a)(1): All efficiency values are at 35
percent per-unit load.
(2) * * *
Note 2 to paragraph (a)(2): All efficiency values are at 35
percent per-unit load.
(b) * * *
(1) * * *
Note 3 to paragraph (b)(1): All efficiency values are at 50
percent per-unit load.
(2) * * *
Note 4 to paragraph (b)(2): All efficiency values are at 50
percent per-unit load.
(c) * * *
(1) * * *
Note 5 to paragraph (c)(1): All efficiency values are at 50
percent per-unit load.
(2) * * *
Note 6 to paragraph (c)(2): All efficiency values are at 50
percent per-unit load.
* * * * *
0
5. Appendix A to subpart K of part 431 is amended by:
0
a. In section 2.0:
0
i. Revising the section heading;
0
ii. Removing paragraphs (a) and (b); and
0
iii. Adding sections 2.1, 2.2, and 2.3;
0
b. Adding paragraph (c) to section 3.1;
0
c. Revising section 3.2.1.1;
0
d. Revising paragraph (b) in section 3.2.1.2;
0
e. Revising section 3.2.2;
0
f. Revising section 3.3;
0
g. Revising paragraph (a) introductory text and paragraph (b) in
section 3.3.2;
0
h. Revising section 3.3.3;
0
i. Revising the introductory text and adding paragraphs (f), (g), (h),
and (i) in section 3.4.1;
0
j. Revising paragraph (a) in section 3.4.2;
0
k. Revising paragraph (a) in section 3.5;
0
l. Revising section 4.1;
0
m. Revising paragraph (a) and adding paragraph (c) in section 4.3;
0
n. Revising section 4.4.3.3;
0
o. Revising paragraph (c) of section 4.5.3.2;
0
p. Revising section 5.1;
0
q. Revising section 6.0;
0
r. Revising section 6.1;
0
s. Revising paragraph (a) in section 6.2; and
0
t. Adding section 7.0.
The additions and revisions read as follows:
Appendix A to Subpart K of Part 431--Uniform Test Method for Measuring
the Energy Consumption of Distribution Transformers
* * * * *
2.0 Per-Unit Load, Reference Temperature, and Accuracy Requirements
2.1 Per-Unit Load
In conducting the test procedure in this appendix for the
purpose of:
(a) Certification to an energy conservation standard, the
applicable per-unit load in Table 2.1 must be used; or
(b) Making voluntary representations as provided in section 7.0
at an additional per-unit load, select the per-unit load of
interest.
Table 2.1--Per-unit Load for Certification to Energy Conservation
Standards
------------------------------------------------------------------------
Per-unit
Distribution transformer category load
(percent)
------------------------------------------------------------------------
Liquid-immersed............................................. 50
Medium-voltage dry-type..................................... 50
Low-voltage dry-type........................................ 35
------------------------------------------------------------------------
2.2 Reference Temperature
In conducting the test procedure in this appendix for the
purpose of:
(a) Certification to an energy conservation standard, the
applicable reference temperature in Table 2.2 must be used; or
(b) Making voluntary representations as provided in section 7.0
at an additional reference temperature, select the reference
temperature of interest.
[[Page 51253]]
Table 2.2--Reference Temperature for Certification to Energy
Conservation Standards
------------------------------------------------------------------------
Distribution transformer category Reference temperature
------------------------------------------------------------------------
Liquid-immersed........................... 20 [deg]C for no-load loss.
55 [deg]C for load loss.
Medium-voltage dry-type................... 20 [deg]C for no-load loss.
75 [deg]C for load loss.
Low-voltage dry-type...................... 20 [deg]C for no-load loss.
75 [deg]C for load loss.
------------------------------------------------------------------------
2.3 Accuracy Requirements
(a) Equipment and methods for loss measurement must be
sufficiently accurate that measurement error will be limited to the
values shown in Table 2.3.
Table 2.3--Test System Accuracy Requirements for Each Measured Quantity
------------------------------------------------------------------------
Measured quantity Test system accuracy
------------------------------------------------------------------------
Power Losses......................... 3.0%.
Voltage.............................. 0.5%.
Current.............................. 0.5%.
Resistance........................... 0.5%.
Temperature.......................... 1.5 [deg]C for liquid-
immersed distribution
transformers, and 2.0 [deg]C for low-voltage
dry-type and medium-voltage dry-
type distribution transformers.
------------------------------------------------------------------------
(b) Only instrument transformers meeting the 0.3 metering
accuracy class, or better, may be used under this test method.
3.0 * * *
3.1 General Considerations
* * * * *
(c) Measure the direct current resistance (Rdc) of
transformer windings by one of the methods outlined in section 3.3.
The methods of section 3.5 must be used to correct load losses to
the applicable reference temperature from the temperature at which
they are measured. Observe precautions while taking measurements,
such as those in section 3.4, in order to maintain measurement
uncertainty limits specified in Table 2.3 of this appendix.
* * * * *
3.2.1.1 Methods
Record the winding temperature (Tdc) of liquid-
immersed transformers as the average of either of the following:
(a) The measurements from two temperature sensing devices (for
example, thermocouples) applied to the outside of the transformer
tank and thermally insulated from the surrounding environment, with
one located at the level of the insulating liquid and the other
located near the tank bottom or at the lower radiator header if
applicable; or
(b) The measurements from two temperature sensing devices
immersed in the insulating liquid, with one located directly above
the winding and other located directly below the winding.
3.2.1.2 Conditions
* * * * *
(b) The temperature of the insulating liquid has stabilized, and
the difference between the top and bottom temperature does not
exceed 5 [deg]C. The temperature of the insulating liquid is
considered stable if the top liquid temperature does not vary more
than 2 [deg]C in a 1-h period.
3.2.2 Dry-Type Distribution Transformers
Record the winding temperature (Tdc) of dry-type
transformers as one of the following:
(a) For ventilated dry-type units, use the average of readings
of four or more thermometers, thermocouples, or other suitable
temperature sensors inserted within the coils. Place the sensing
points of the measuring devices as close as possible to the winding
conductors; or
(b) For sealed units, such as epoxy-coated or epoxy-encapsulated
units, use the average of four or more temperature sensors located
on the enclosure and/or cover, as close to different parts of the
winding assemblies as possible; or
(c) For ventilated units or sealed units, use the ambient
temperature of the test area, only if the following conditions are
met:
(1) All internal temperatures measured by the internal
temperature sensors must not differ from the test area ambient
temperature by more than 2 [deg]C. Enclosure surface temperatures
for sealed units must not differ from the test area ambient
temperature by more than 2 [deg]C.
(2) Test area ambient temperature must not have changed by more
than 3 [deg]C for 3 hours before the test.
(3) Neither voltage nor current has been applied to the unit
under test for 24 hours. In addition, increase this initial 24-hour
period by any added amount of time necessary for the temperature of
the transformer windings to stabilize at the level of the ambient
temperature. However, this additional amount of time need not exceed
24 hours (i.e., after 48 hours, the transformer windings can be
assumed to have stabilized at the level of the ambient temperature.
Any stabilization time beyond 48 hours is optional).
3.3 Resistance Measurement Methods
Make resistance measurements using either the resistance bridge
method (section 3.3.1), the voltmeter-ammeter method (section 3.3.2)
or resistance meters (section 3.3.3). In each instance when this
appendix is used to test more than one unit of a basic model to
determine the efficiency of that basic model, the resistance of the
units being tested may be determined from making resistance
measurements on only one of the units.
* * * * *
3.3.2 Voltmeter-Ammeter Method
(a) Employ the voltmeter-ammeter method only if the test current
is limited to 15 percent of the winding current. Connect the
transformer winding under test to the circuit shown in Figure 3.3 of
this appendix.
* * * * *
(b) To perform the measurement, turn on the source to produce
current no larger than 15 percent of the rated current for the
winding. Wait until the current and voltage readings have stabilized
and then take a minimum of four readings of voltage and current.
Voltage and current readings must be taken simultaneously for each
of the readings. Calculate the average voltage and average current
using the readings. Determine the winding resistance Rdc
by using equation 3-4 as follows:
[GRAPHIC] [TIFF OMITTED] TR14SE21.014
Where:
Vmdc is the average voltage measured by the voltmeter V;
and
Imdc is the average current measured by the ammeter (A).
* * * * *
3.3.3 Resistance Meters
Resistance meters may be based on voltmeter-ammeter, or
resistance bridge, or some other operating principle. Any meter used
to measure a transformer's winding resistance must have
specifications for resistance range, current range, and ability to
measure highly inductive resistors that cover the characteristics of
the transformer being tested. Also, the meter's specifications for
accuracy must meet the applicable criteria of Table 2.3 in section
2.3 of this appendix.
* * * * *
3.4.1 Required Actions
The following requirements must be observed when making
resistance measurements:
* * * * *
(f) Keep the polarity of the core magnetization constant during
all resistance measurements.
(g) For single-phase windings, measure the resistance from
terminal to terminal. The total winding resistance is the terminal-
to-terminal measurement. For series-parallel windings, the total
winding resistance is the sum of the series terminal-to-terminal
section measurements.
(h) For wye windings, measure the resistance from terminal to
terminal or from terminal to neutral. For the total winding
resistance, the resistance of the lead from the neutral connection
to the neutral bushing may be excluded. For terminal-to-terminal
measurements, the total resistance reported is the sum of the three
measurements divided by two.
(i) For delta windings, measure resistance from terminal to
terminal with the delta closed or from terminal to terminal with the
[[Page 51254]]
delta open to obtain the individual phase readings. The total
winding resistance is the sum of the three-phase readings if the
delta is open. If the delta is closed, the total winding resistance
is the sum of the three phase-to-phase readings times 1.5.
3.4.2 Guideline for Time Constant
(a) The following guideline is suggested for the tester as a
means to facilitate the measurement of resistance in accordance with
the accuracy requirements of section 2.3:
* * * * *
3.5 Conversion of Resistance Measurements
(a) Resistance measurements must be corrected from the
temperature at which the winding resistance measurements were made,
to the reference temperature.
* * * * *
4.0 * * *
4.1 General Considerations
The efficiency of a transformer is computed from the total
transformer losses, which are determined from the measured value of
the no-load loss and load loss power components. Each of these two
power loss components is measured separately using test sets that
are identical, except that shorting straps are added for the load-
loss test. The measured quantities need correction for
instrumentation losses and may need corrections for known phase
angle errors in measuring equipment and for the waveform distortion
in the test voltage. Any power loss not measured at the applicable
reference temperature must be adjusted to that reference
temperature. The measured load loss must also be adjusted to a
specified output loading level if not measured at the specified
output loading level. Test all distribution transformers using a
sinusoidal waveform (k = 1). Measure losses with the transformer
energized by a 60 Hz supply.
* * * * *
4.3 Test Sets
(a) The same test set may be used for both the no-load loss and
load loss measurements provided the range of the test set
encompasses the test requirements of both tests. Calibrate the test
set to national standards to meet the tolerances in Table 2.3 in
section 2.3 of this appendix. In addition, the wattmeter, current
measuring system and voltage measuring system must be calibrated
separately if the overall test set calibration is outside the
tolerance as specified in section 2.3 or the individual phase angle
error exceeds the values specified in section 4.5.3.
* * * * *
(c) Both load loss and no-load loss measurements must be made
from terminal to terminal.
* * * * *
4.4.3.3 Correction of No-Load Loss to Reference Temperature
After correcting the measured no-load loss for waveform
distortion, correct the loss to the reference temperature. For both
certification to energy conservation standards and voluntary
representations, if the correction to reference temperature is
applied, then the core temperature of the transformer during no-load
loss measurement (Tnm) must be determined within 10 [deg]C of the true average core temperature. For
certification to energy conservation standards only, if the no-load
loss measurements were made between 10 [deg]C and 30 [deg]C, this
correction is not required. Correct the no-load loss to the
reference temperature by using equation 4-2 as follows:
[GRAPHIC] [TIFF OMITTED] TR14SE21.015
Where:
Pnc is the no-load losses corrected for waveform distortion and then
to the reference temperature;
Pnc1 is the no-load losses, corrected for waveform distortion, at
temperature Tnm;
Tnm is the core temperature during the measurement of no-load
losses; and
Tnr is the reference temperature.
* * * * *
4.5.3.2 Correction for Phase Angle Errors
* * * * *
(c) If the correction for phase angle errors is to be applied,
first examine the total system phase angle ([beta]w-
[beta]v + [beta]c). Where the total system
phase angle is equal to or less than 12 milliradians
(41 minutes), use either equation 4-4 or 4-5 to correct
the measured load loss power for phase angle errors, and where the
total system phase angle exceeds 12 milliradians (41 minutes) use equation 4-5, as follows:
[GRAPHIC] [TIFF OMITTED] TR14SE21.016
* * * * *
5.0 * * *
5.1 Output Loading Level Adjustment
If the per-unit load selected in section 2.1 is different from
the per-unit load at which the load loss power measurements were
made, then adjust the corrected load loss power, Plc2, by
using equation 5-1 as follows:
[GRAPHIC] [TIFF OMITTED] TR14SE21.017
Where:
Plc is the adjusted load loss power to the per-unit load;
Plc2 is as calculated in section 4.5.3.3;
Por is the rated transformer apparent power (name plate);
Pos is the adjusted rated transformer apparent power, where Pos =
PorL; and
L is the per-unit load, e.g., if the per-unit load is 50 percent
then ``L'' is 0.5.
* * * * *
6.0 Test Equipment Calibration and Certification
Maintain and calibrate test equipment and measuring instruments,
maintain calibration records, and perform other test and measurement
quality assurance procedures according to the following sections.
The calibration of the test set must confirm the accuracy of the
test set to that specified in section 2.3, Table 2.3 of this
appendix.
6.1 Test Equipment
The party performing the tests must control, calibrate, and
maintain measuring and test equipment, whether or not it owns the
equipment, has the equipment on loan, or the equipment is provided
by another party. Equipment must be used in a manner which assures
that measurement uncertainty is known and is consistent with the
required measurement capability.
6.2 Calibration and Certification
* * * * *
[[Page 51255]]
(a) Identify the measurements to be made, the accuracy required
(section 2.3) and select the appropriate measurement and test
equipment;
* * * * *
7.0 Test Procedure for Voluntary Representations
Follow sections 1.0 through 6.0 of this appendix using the per-
unit load and/or reference temperature of interest for voluntary
representations of efficiency, and corresponding values of load loss
and no-load loss at additional per-unit load and/or reference
temperature. Representations made at a per-unit load and/or
reference temperature other than those required to comply with the
energy conservation standards at Sec. 431.196 must be in addition
to, and not in place of, a representation at the required DOE
settings for per-unit load and reference temperature. As a best
practice, the additional settings of per-unit load and reference
temperature should be provided with the voluntary representations.
[FR Doc. 2021-19366 Filed 9-13-21; 8:45 am]
BILLING CODE 6450-01-P
