Electric Power Generation, Transmission, and Distribution; Electrical Protective Equipment; Limited Reopening of Record, 62942-62945 [E8-25079]
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62942
Federal Register / Vol. 73, No. 205 / Wednesday, October 22, 2008 / Proposed Rules
Issued in Fort Worth, TX on October 10,
2008.
Walter Tweedy,
Acting Manager, Operations Support Group,
ATO Central Service Center.
[FR Doc. E8–25049 Filed 10–21–08; 8:45 am]
BILLING CODE 4910–13–P
DEPARTMENT OF LABOR
Occupational Safety and Health
Administration
29 CFR Parts 1910 and 1926
[Docket OSHA–S215–2006–0063]
RIN 1218–AB67
Electric Power Generation,
Transmission, and Distribution;
Electrical Protective Equipment;
Limited Reopening of Record
Occupational Safety and Health
Administration (OSHA), U.S.
Department of Labor.
ACTION: Notice of limited reopening of
rulemaking record.
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AGENCY:
SUMMARY: On June 15, 2005, OSHA
published a proposed rule to revise the
general industry and construction
standards for electric power generation,
transmission, and distribution work and
for electrical protective equipment.
Public comments were received, a
hearing was held, and the final
posthearing briefs were due on July 14,
2006.
The proposed general industry and
construction standards for electric
power generation, transmission, and
distribution work included revised
minimum approach distance tables.
Those tables limit how close an
employee (or a conductive object he or
she is contacting) may get to an
energized circuit part. After the
rulemaking record on the proposal
closed, the technical committee
responsible for developing the tables in
the consensus standards on which the
proposal was based discovered what in
their view was an error in their
calculation of minimum approach
distances for certain voltages.
OSHA is reopening the record on this
proposal to obtain comments related to
the affected minimum approach
distances. The record will remain open
on this limited basis for 30 days.
DATES: Comments must be postmarked
no later than November 21, 2008.
ADDRESSES: You may submit comments,
identified by Docket No. OSHA–S215–
2006–0063, by any of the following
methods:
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15:17 Oct 21, 2008
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• Federal eRulemaking Portal: https://
www.regulations.gov. Follow the
instructions for submitting comments.
• Fax: If your comments, including
attachments, do not exceed 10 pages,
you may fax them to the OSHA Docket
Office at (202) 693–1648.
• Mail, hand delivery, express mail,
messenger, or courier service: You must
submit two copies of your comments
and attachments to the OSHA Docket
Office, Docket No. OSHA–S215–2006–
0063, U.S. Department of Labor, Room
N–2625, 200 Constitution Avenue, NW.,
Washington, DC 20210; telephone (202)
693–2350 (OSHA’s TTY number is (877)
889–5627). Deliveries (hand, express
mail, messenger, and courier service)
are accepted during the Department of
Labor’s and Docket Office’s normal
business hours, 8:15 a.m.–4:45 p.m.,
e.s.t.
Instructions: All submissions must
include the agency name and the docket
number (Docket No. OSHA–S215–2006–
0063) or Regulatory Information
Number (RIN 1218–AB67) for this
rulemaking. All comments received will
be posted without change to https://
dockets.osha.gov, including any
personal information provided.
Docket: To read or download
comments and materials submitted in
response to this Federal Register notice,
go to Docket OSHA–S215–2006–0063 at
https://www.regulations.gov or at the
OSHA Docket Office at the previously
listed address. All comments and
submissions are listed in the https://
www.regulations.gov index. However,
some information (for example,
copyrighted material) is not publicly
available to read or download through
that Web page. All comments and
submissions, including copyrighted
material, are available for inspection
and copying at the OSHA Docket Office.
Electronic copies of this Federal
Register document are available at
https://www.regulations.gov. This
document, as well as news releases and
other relevant information, also are
available at OSHA’s Web page at https://
www.osha.gov.
FOR FURTHER INFORMATION CONTACT:
General information and press inquiries:
Contact Ms. Jennifer Ashley, Office of
Communications, Room N–3647, OSHA,
U.S. Department of Labor, 200
Constitution Avenue, NW., Washington,
DC 20210; telephone (202) 693–1999.
SUPPLEMENTARY INFORMATION: On June
15, 2005, OSHA issued a proposed rule
to revise the general industry and
construction standards for electric
power generation, transmission, and
distribution work and for electrical
protective equipment (70 FR 34822).
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The Agency solicited public comments
and held a public hearing on March 6
through 14, 2006. Administrative Law
Judge William Colwell set a deadline of
July 14, 2006, for the filing of written
comments, summations, position
statements, and briefs.
The proposed requirements for
electric power generation, transmission,
and distribution work for general
industry and construction would be
contained in 29 CFR 1910.269 and 29
CFR part 1926, subpart V (§§ 1926.950
through 1926.968), respectively.
Proposed § 1926.960(c)(1) would require
employees to maintain minimum
approach distances from exposed
energized parts. The minimum
approach distances are specified in
proposed Tables V–2 through V–6.
Existing § 1910.269(l)(2) and proposed
Tables R–6 through R–10 contain
equivalent requirements for general
industry.
OSHA developed the minimum
approach distance tables in the proposal
using the following principles (see 70
FR 34862):
• ANSI/IEEE 1 Standard 516–1987
was to be the electrical basis for
approach distances: Table 4 (Alternating
Current) and Table 5 (Direct Current) for
voltages above 72.5 kV. Lower voltages
were to be based on ANSI/IEEE
Standard 4. The application of ANSI/
IEEE Standard 516–1987 was inclusive
of the formula used by that standard to
derive electrical clearance distances.
• Altitude correction factors were to
be in accordance with ANSI/IEEE
Standard 516–1987, Table 1.
• The maximum design transient
overvoltage data to be used in the
development of the basic approach
distance tables were:
Æ 3.0 per unit for voltages of 362 kV and
less
Æ 2.4 per unit for 500 to 550 kV
Æ 2.0 per unit for 765 to 800 kV
• All phase-to-phase values were to
be calculated from the EPRI 2
Transmission Line Reference Book for
115 to 138 kV.
• An inadvertent movement factor
(ergonomic component) intended to
account for errors in judging the
approach distance was to be added to all
basic electrical approach distances
(electrical component) for all voltage
ranges. A distance of 0.31 meters (1 foot)
was to be added to all voltage ranges.
An additional 0.3 meters (1 foot) was to
be added to voltage ranges below 72.6
kV.
1 ANSI is the American National Standards
Institute. IEEE is the Institute of Electrical and
Electronics Engineers, Inc.
2 EPRI is the Electric Power Research Institute.
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Federal Register / Vol. 73, No. 205 / Wednesday, October 22, 2008 / Proposed Rules
• The voltage reduction allowance for
controlled maximum transient
overvoltage was to be such that the
minimum allowable approach distance
was not less than the given approach
distance specified for the highest
voltage of the given range.
• The transient overvoltage tables
were to be applied only at voltage
ranges inclusive of 72.6 kV to 800 kV.
All tables were to be established using
the higher voltage of each separate
voltage range.
D = (C + a ) × pu × Vmax
Where:
D = Electrical component of the minimum
approach distance in air in feet
C = 0.01 to take care of correction factors
associated with the variation of gap
sparkover with voltage
a = A factor relating to the saturation of air
at voltages 3 of 345 kV or higher
pu = Maximum anticipated transient
overvoltage, in per unit (p.u.)
Where:
pup = p.u. phase-to-phase maximum transient
overvoltage
pug = p.u. phase-to-ground maximum
transient overvoltage.
This value was to be used in Equation
(1) to calculate the phase-to-phase
minimum approach distance (MAD).
The technical committees responsible
for ANSI/IEEE and the National
Electrical Safety Code (NESC, ANSI C2)
calculated minimum approach distances
based on these equations. Because
OSHA intended to use the same
methodology, it relied on the technical
committees’ calculations as they
appeared in the two consensus
standards and carried those distances
into the proposed standard.
As noted in Appendix B to existing
§ 1910.269 and in Appendix B to
proposed subpart V, the following
equation is used to calculate the
electrical component of the minimum
approach distance for voltages of 72.6
kV to 800 kV:
Equation (1)
Vmax = Maximum rms system line-to-ground
voltage in kilovolts—it should be the
‘‘actual’’ maximum, or the normal
highest voltage for the range (for
example, 10 percent above the nominal
voltage).
Source: Formula developed from ANSI/
IEEE Standard No. 516–1987.
For phase-to-phase exposures, the
maximum phase-to-phase transient
pu p = pu g +1.6
62943
overvoltage must be used to calculate
minimum approach distances from one
phase to another. As noted in Appendix
B to existing § 1910.269 and in
Appendix B to proposed subpart V, the
following equation is used in
determining the phase-to-phase
maximum transient overvoltage based
on the per unit of the system nominal
voltage phase-to-ground crest:
Equation (2)
During the most recent revision cycle
for ANSI/IEEE Standard 516, the IEEE
technical committee responsible for
revising that standard identified what in
their view was an error in the
calculations of phase-to-phase
minimum approach distances for
nominal voltages 230 kV and higher. At
these voltages, the saturation factor, a,
which appears in Equation (1), varies
depending upon the voltage. The value
of a increases with increasing voltage.
The NESC subcommittee originally
calculated the phase-to-phase minimum
approach distances using a value for the
saturation factor, a, corresponding to the
phase-to-ground maximum transient
overvoltage rather than the maximum
phase-to-phase transient overvoltage.4
Because the MADs used in OSHA’s
2005 proposal were taken from the
consensus standard, OSHA wants to
obtain comments on whether changes
are necessary to the tables as proposed.
The IEEE committee proposed a
correction in a draft revised IEEE
Standard 516 (Draft #9).5 Table 1 shows
the difference between the minimum
approach distances in that draft IEEE
Standard 516 and those contained in
proposed § 1910.269 Table R–6 and
proposed Subpart V Table V–2 for
voltages over 72.5 kV. A subsequent
draft from the IEEE committee (Draft
#10) dropped values for voltages with
temporary overvoltages exceeding 1600
kV.6 Draft #10 leaves the determination
of these values to ‘‘good engineering
judgment.’’
TABLE 1—COMPARISON OF MINIMUM APPROACH DISTANCES
Distance (m)
Phase-to-ground exposure
Phase-to-phase exposure
Nominal voltage in kilovolts phase-to-phase
Draft IEEE
516 1
Proposed
tables R–6
and V–2
1.01
1.15
1.29
1.71
2.72
3.54
0.95
1.09
1.22
1.59
2.59
3.42
1.36
1.57
1.85
2.91
5.13
6.89
1.29
1.50
1.71
2.27
3.80
5.50
72.6 to 121 .......................................................................................................
138 to 145 ........................................................................................................
161 to 169 ........................................................................................................
230 to 242 ........................................................................................................
345 to 362 ........................................................................................................
500 to 550 ........................................................................................................
3 This voltage is the maximum transient
overvoltage.
4 ANSI/IEEE Standard 516–1987 did not contain
distances for phase-to-phase exposures. The NESC
subcommittee derived them by applying the IEEE
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equation to the phase-to-phase temporary
overvoltages calculated using Equation (2).
5 This document is available for inspection and
copying in the Docket Office at the address listed
in the ADDRESSES section of this notice.
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6 This document is also available for inspection
and copying in the Docket Office at the address
listed in the ADDRESSES section of this notice.
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EP22OC08.001</MATH>
Proposed
tables R–6
and V–2
EP22OC08.000</MATH>
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Draft IEEE
516 1
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Federal Register / Vol. 73, No. 205 / Wednesday, October 22, 2008 / Proposed Rules
TABLE 1—COMPARISON OF MINIMUM APPROACH DISTANCES—Continued
Distance (m)
Phase-to-ground exposure
Phase-to-phase exposure
Nominal voltage in kilovolts phase-to-phase
Draft IEEE
516 1
Proposed
tables R–6
and V–2
Draft IEEE
516 1
Proposed
tables R–6
and V–2
4.64
4.53
9.35
7.91
765 to 800 ........................................................................................................
1 Draft
#9 of IEEE Standard 516 provides separate minimum approach distances for exposures with and without tools in the air gap. The distances in the table are for tools in the air gap (called ‘‘minimum tool insulation distances’’ in the IEEE standard.). The NESC minimum approach
distances tables are derived from the distances in IEEE Standard 516 corresponding to exposures with tools in the air gap.
As can be seen from Table 1, the
IEEE’s proposed approach from Draft #9
results in a substantial increase in MAD
for phase-to-phase exposures at voltages
of 230 kV and higher.
For purposes of the public’s
consideration of the issues in this
reopening notice, OSHA points out the
following technical issues:
1. For voltages over 72.5 kV, the
electrical component of the minimum
approach distances 7 in OSHA’s
proposal is based on testing of rod-torod gaps performed by 13 laboratories.
This testing extends to approximately
1.6 MV. This voltage is sufficient to
cover the maximum transient
overvoltage for all phase-to-ground
exposures. However, it does not extend
to the maximum transient overvoltages
for phase-to-phase exposures of voltages
362 kV and higher, as shown in Table
2.
TABLE 2—MAXIMUM TRANSIENT OVERVOLTAGES
Maximum transient overvoltage (in kV)
System voltage (in kV) Vmax
Maximum anticipated per-unit
transient overvoltage pu
362
552
800
3.0
2.4
2.0
Phase-to-ground
exposure
Phase-to-phase
exposure
1086
1325
2208
1665
2208
2880
ebenthall on PROD1PC60 with PROPOSALS
Note: The maximum transient overvoltage for phase-to-ground exposure equals Vmax × pu. The maximum overvoltage for phase-to-phase exposures equals Vmax × (pu + 1.6).
In Draft #9, the IEEE committee
addressed this issue by extending the
equations used for calculating the
minimum air insulation distance
beyond the highest voltage covered by
the test data. Other approaches using
the same criteria upon which the
minimum approach distances are based
could include: (1) Using available test
data for conductor-to-conductor gaps
and converting them to equivalent rodto-rod values, and (2) commissioning
further tests.
2. IEEE Drafts #9 and #10 also include
other refinements of the method used to
calculate minimum approach distances
intended to make the calculations more
precise and repeatable. For example, the
saturation factor is now based on
equations resulting from curve fitting
the test data rather than from reading
the value directly from a graph of these
data.
3. If the minimum approach distances
are based on the minimum tool
insulation distance, as is done in the
NESC, there would be additional slight
increases in MAD for all voltages of 72.6
kV and higher with both phase-toground and phase-to-phase exposures.
In light of the IEEE committee’s draft
revisions, OSHA is reopening the record
on the electric power generation,
transmission, and distribution standard
to invite comments, evidence, and data
on the limited question of whether the
Agency should adopt minimum
approach distances different from those
proposed for voltages of 72.6 kV and
higher. The Agency strives to adopt a
final rule that is based on sound and upto-date engineering, and scientific
principles and is specifically inviting
comments on the following questions:
1. Should OSHA adopt MADs that are
different from those proposed for
voltages of 72.6 kV and higher and, if so,
should it adopt the distances in Draft #9
or #10 of IEEE Standard 516?
2. Are there methods other than those
in Drafts #9 and #10 of IEEE Standard
516 that would be more appropriate in
the calculation of MAD for maximum
transient overvoltages beyond existing
data for rod-to-rod gaps?
3. Should MAD for voltages of 72.6 kV
and higher be based on the minimum
tool insulation distance as is the case in
the 2007 NESC?
4. Should the final rule include
separate minimum approach distance
tables for air gaps and for tools as is
done in Drafts #9 and #10 of IEEE
Standard 516?
OSHA is reopening the record solely
on issues related to minimum approach
distances for voltages of 72.6 kV and
higher. The record is not being reopened
on any other issue.
List of Subjects in 29 CFR Parts 1910
and 1926
Electric power, Fire prevention,
Hazardous substances, Occupational
safety and health, Safety.
Authority and Signature
This document was prepared under
the direction of Edwin G. Foulke, Jr.,
Assistant Secretary of Labor for
Occupational Safety and Health, U.S.
Department of Labor, 200 Constitution
Avenue, NW., Washington, DC 20210. It
is issued pursuant to sections 4, 6, and
8 of the Occupational Safety and Health
Act of 1970 (29 U.S.C. 653, 655, 657),
7 The electrical component of the minimum
approach distance is called ‘‘minimum tool
insulation distance’’ or MTID in the IEEE draft.
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Federal Register / Vol. 73, No. 205 / Wednesday, October 22, 2008 / Proposed Rules
Secretary’s Order 5–2007 (72 FR 31160),
and 29 CFR Part 1911.
Signed at Washington, DC, this 16th day of
October 2008.
Edwin G. Foulke, Jr.
Assistant Secretary of Labor for Occupational
Safety and Health.
[FR Doc. E8–25079 Filed 10–21–08; 8:45 am]
BILLING CODE 4510–26–P
ENVIRONMENTAL PROTECTION
AGENCY
during the Regional Office normal hours
of operation, and special arrangements
should be made for deliveries of boxed
information. The Regional Office official
hours of business are Monday through
Friday, 8:30 a.m. to 4:30 a.m., excluding
Federal holidays.
Please see the direct final rule which
is located in the Rules section of this
Federal Register for detailed
instructions on how to submit
comments.
FOR FURTHER INFORMATION CONTACT:
40 CFR Part 52
[EPA–R05–OAR–2008–0389; FRL–8711–4]
Approval and Promulgation of Air
Quality Implementation Plans;
Wisconsin; Approval of Rule
Clarifications
Environmental Protection
Agency (EPA).
ACTION: Proposed rule.
ebenthall on PROD1PC60 with PROPOSALS
AGENCY:
15:17 Oct 21, 2008
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In the
Final Rules section of this Federal
Register, EPA is approving the State’s
SIP submittal as a direct final rule
without prior proposal because the
Agency views this as a noncontroversial
submittal and anticipates no adverse
comments. A detailed rationale for the
approval is set forth in the direct final
rule. If no adverse comments are
received in response to this rule, no
further activity is contemplated. If EPA
receives adverse comments, the direct
final rule will be withdrawn and all
public comments received will be
addressed in a subsequent final rule
based on this proposed rule. EPA will
not institute a second comment period.
Any parties interested in commenting
on this action should do so at this time.
Please note that if EPA receives adverse
comment on an amendment, paragraph,
or section of this rule and if that
provision may be severed from the
remainder of the rule, EPA may adopt
as final those provisions of the rule that
are not the subject of an adverse
comment. For additional information,
see the direct final rule which is located
in the Rules section of this Federal
Register.
SUPPLEMENTARY INFORMATION:
SUMMARY: EPA is proposing to approve
revisions to the Wisconsin State
Implementation Plan (SIP) submitted by
the Wisconsin Department of Natural
Resources (WDNR) on March 28, 2008.
The WDNR has submitted for approval
revisions to incorporate Federal
regulations into the Wisconsin
Administrative Code, to clarify
construction permit requirements under
general permits, to revise portable
source relocation requirements, and to
amend rule language to streamline the
minor revision permit process to allow
construction permits to be issued
concurrently with operation permits.
EPA is approving these revisions
because they are consistent with Federal
regulations governing State permit
programs.
DATES: Comments must be received on
or before November 21, 2008.
ADDRESSES: Submit your comments,
identified by Docket ID No. EPA–R05–
OAR–2008–0389, by one of the
following methods:
1. www.regulations.gov: Follow the
on-line instructions for submitting
comments.
2. E-mail: blakley.pamela@epa.gov.
3. Fax: (312) 886–5824.
4. Mail: Pamela Blakley, Chief, Air
Permits Section, Air Programs Branch
(AR–18J), U.S. Environmental
Protection Agency, 77 West Jackson
Boulevard, Chicago, Illinois 60604.
5. Hand Delivery: Pamela Blakley,
Chief, Air Permits Section, Air Programs
Branch (AR–18J), U.S. Environmental
Protection Agency, 77 West Jackson
Boulevard, Chicago, Illinois 60604.
Such deliveries are only accepted
VerDate Aug<31>2005
Susan Castellanos, Environmental
Engineer, Air Permits Section, Air
Programs Branch (AR–18J), U.S.
Environmental Protection Agency,
Region 5, 77 West Jackson Boulevard,
Chicago, Illinois 60604, (312) 353–2654,
castellanos.susan@epa.gov.
Dated: August 21, 2008.
Lynn Buhl,
Regional Administrator, Region 5.
[FR Doc. E8–25040 Filed 10–21–08; 8:45 am]
BILLING CODE 6560–50–P
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62945
ENVIRONMENTAL PROTECTION
AGENCY
40 CFR Part 52
[EPA–R03–OAR–2008–0736; FRL–8732–2]
Approval and Promulgation of Air
Quality Implementation Plans; The
Metropolitan Washington
Nonattainment Area; Determination of
Attainment of the Fine Particle
Standard
Environmental Protection
Agency (EPA).
ACTION: Proposed rule.
AGENCY:
SUMMARY: EPA is proposing to
determine that the Metropolitan
Washington, DC-MD-VA nonattainment
area for the 1997 fine particle (PM2.5)
National Ambient Air Quality Standard
(NAAQS) has attained the 1997 PM2.5
NAAQS. This proposed determination
is based upon quality assured, quality
controlled, and certified ambient air
monitoring data that show that the area
has monitored attainment of the 1997
PM2.5 NAAQS since the 2004–2006
monitoring period, and continues to
monitor attainment of the standard
based on 2005–2007 data. In addition,
quality controlled and quality assured
monitoring data for 2008 that are
available in the EPA Air Quality System
(AQS) database, but not yet certified,
show this area continues to attain the
1997 PM2.5 NAAQS. If this proposed
determination is made final, the
requirements for this area to submit an
attainment demonstration and
associated reasonably available
measures, a reasonable further progress
plan, contingency measures, and other
planning State Implementation Plans
(SIPs) related to attainment of the
standard shall be suspended for so long
as the area continues to attain the 1997
PM2.5 NAAQS.
DATES: Written comments must be
received on or before November 21,
2008.
Submit your comments,
identified by Docket ID Number EPA–
R03–OAR–2008–0736 by one of the
following methods:
A. www.regulations.gov. Follow the
online instructions for submitting
comments.
B. E-mail: fernandez.cristina@epa.gov.
C. Mail: EPA–R03–OAR–2008–0736,
Cristina Fernandez, Chief, Air Quality
Planning Branch, Mailcode 3AP21, U.S.
Environmental Protection Agency,
Region III, 1650 Arch Street,
Philadelphia, Pennsylvania 19103.
D. Hand Delivery: At the previouslylisted EPA Region III address. Such
ADDRESSES:
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]]>Agencies
[Federal Register Volume 73, Number 205 (Wednesday, October 22, 2008)]
[Proposed Rules]
[Pages 62942-62945]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: E8-25079]
=======================================================================
-----------------------------------------------------------------------
DEPARTMENT OF LABOR
Occupational Safety and Health Administration
29 CFR Parts 1910 and 1926
[Docket OSHA-S215-2006-0063]
RIN 1218-AB67
Electric Power Generation, Transmission, and Distribution;
Electrical Protective Equipment; Limited Reopening of Record
AGENCY: Occupational Safety and Health Administration (OSHA), U.S.
Department of Labor.
ACTION: Notice of limited reopening of rulemaking record.
-----------------------------------------------------------------------
SUMMARY: On June 15, 2005, OSHA published a proposed rule to revise the
general industry and construction standards for electric power
generation, transmission, and distribution work and for electrical
protective equipment. Public comments were received, a hearing was
held, and the final posthearing briefs were due on July 14, 2006.
The proposed general industry and construction standards for
electric power generation, transmission, and distribution work included
revised minimum approach distance tables. Those tables limit how close
an employee (or a conductive object he or she is contacting) may get to
an energized circuit part. After the rulemaking record on the proposal
closed, the technical committee responsible for developing the tables
in the consensus standards on which the proposal was based discovered
what in their view was an error in their calculation of minimum
approach distances for certain voltages.
OSHA is reopening the record on this proposal to obtain comments
related to the affected minimum approach distances. The record will
remain open on this limited basis for 30 days.
DATES: Comments must be postmarked no later than November 21, 2008.
ADDRESSES: You may submit comments, identified by Docket No. OSHA-S215-
2006-0063, by any of the following methods:
Federal eRulemaking Portal: https://www.regulations.gov.
Follow the instructions for submitting comments.
Fax: If your comments, including attachments, do not
exceed 10 pages, you may fax them to the OSHA Docket Office at (202)
693-1648.
Mail, hand delivery, express mail, messenger, or courier
service: You must submit two copies of your comments and attachments to
the OSHA Docket Office, Docket No. OSHA-S215-2006-0063, U.S. Department
of Labor, Room N-2625, 200 Constitution Avenue, NW., Washington, DC
20210; telephone (202) 693-2350 (OSHA's TTY number is (877) 889-5627).
Deliveries (hand, express mail, messenger, and courier service) are
accepted during the Department of Labor's and Docket Office's normal
business hours, 8:15 a.m.-4:45 p.m., e.s.t.
Instructions: All submissions must include the agency name and the
docket number (Docket No. OSHA-S215-2006-0063) or Regulatory
Information Number (RIN 1218-AB67) for this rulemaking. All comments
received will be posted without change to https://dockets.osha.gov,
including any personal information provided.
Docket: To read or download comments and materials submitted in
response to this Federal Register notice, go to Docket OSHA-S215-2006-
0063 at https://www.regulations.gov or at the OSHA Docket Office at the
previously listed address. All comments and submissions are listed in
the https://www.regulations.gov index. However, some information (for
example, copyrighted material) is not publicly available to read or
download through that Web page. All comments and submissions, including
copyrighted material, are available for inspection and copying at the
OSHA Docket Office.
Electronic copies of this Federal Register document are available
at https://www.regulations.gov. This document, as well as news releases
and other relevant information, also are available at OSHA's Web page
at https://www.osha.gov.
FOR FURTHER INFORMATION CONTACT: General information and press
inquiries: Contact Ms. Jennifer Ashley, Office of Communications, Room
N-3647, OSHA, U.S. Department of Labor, 200 Constitution Avenue, NW.,
Washington, DC 20210; telephone (202) 693-1999.
SUPPLEMENTARY INFORMATION: On June 15, 2005, OSHA issued a proposed
rule to revise the general industry and construction standards for
electric power generation, transmission, and distribution work and for
electrical protective equipment (70 FR 34822). The Agency solicited
public comments and held a public hearing on March 6 through 14, 2006.
Administrative Law Judge William Colwell set a deadline of July 14,
2006, for the filing of written comments, summations, position
statements, and briefs.
The proposed requirements for electric power generation,
transmission, and distribution work for general industry and
construction would be contained in 29 CFR 1910.269 and 29 CFR part
1926, subpart V (Sec. Sec. 1926.950 through 1926.968), respectively.
Proposed Sec. 1926.960(c)(1) would require employees to maintain
minimum approach distances from exposed energized parts. The minimum
approach distances are specified in proposed Tables V-2 through V-6.
Existing Sec. 1910.269(l)(2) and proposed Tables R-6 through R-10
contain equivalent requirements for general industry.
OSHA developed the minimum approach distance tables in the proposal
using the following principles (see 70 FR 34862):
ANSI/IEEE \1\ Standard 516-1987 was to be the electrical
basis for approach distances: Table 4 (Alternating Current) and Table 5
(Direct Current) for voltages above 72.5 kV. Lower voltages were to be
based on ANSI/IEEE Standard 4. The application of ANSI/IEEE Standard
516-1987 was inclusive of the formula used by that standard to derive
electrical clearance distances.
---------------------------------------------------------------------------
\1\ ANSI is the American National Standards Institute. IEEE is
the Institute of Electrical and Electronics Engineers, Inc.
---------------------------------------------------------------------------
Altitude correction factors were to be in accordance with
ANSI/IEEE Standard 516-1987, Table 1.
The maximum design transient overvoltage data to be used
in the development of the basic approach distance tables were:
[cir] 3.0 per unit for voltages of 362 kV and less
[cir] 2.4 per unit for 500 to 550 kV
[cir] 2.0 per unit for 765 to 800 kV
All phase-to-phase values were to be calculated from the
EPRI \2\ Transmission Line Reference Book for 115 to 138 kV.
---------------------------------------------------------------------------
\2\ EPRI is the Electric Power Research Institute.
---------------------------------------------------------------------------
An inadvertent movement factor (ergonomic component)
intended to account for errors in judging the approach distance was to
be added to all basic electrical approach distances (electrical
component) for all voltage ranges. A distance of 0.31 meters (1 foot)
was to be added to all voltage ranges. An additional 0.3 meters (1
foot) was to be added to voltage ranges below 72.6 kV.
[[Page 62943]]
The voltage reduction allowance for controlled maximum
transient overvoltage was to be such that the minimum allowable
approach distance was not less than the given approach distance
specified for the highest voltage of the given range.
The transient overvoltage tables were to be applied only
at voltage ranges inclusive of 72.6 kV to 800 kV. All tables were to be
established using the higher voltage of each separate voltage range.
As noted in Appendix B to existing Sec. 1910.269 and in Appendix B
to proposed subpart V, the following equation is used to calculate the
electrical component of the minimum approach distance for voltages of
72.6 kV to 800 kV:
[GRAPHIC] [TIFF OMITTED] TP22OC08.000
Where:
D = Electrical component of the minimum approach distance in air in
feet
C = 0.01 to take care of correction factors associated with the
variation of gap sparkover with voltage
a = A factor relating to the saturation of air at voltages \3\ of
345 kV or higher
---------------------------------------------------------------------------
\3\ This voltage is the maximum transient overvoltage.
---------------------------------------------------------------------------
pu = Maximum anticipated transient overvoltage, in per unit (p.u.)
Vmax = Maximum rms system line-to-ground voltage in kilovolts--it
should be the ``actual'' maximum, or the normal highest voltage for
the range (for example, 10 percent above the nominal voltage).
Source: Formula developed from ANSI/ IEEE Standard No. 516-1987.
For phase-to-phase exposures, the maximum phase-to-phase transient
overvoltage must be used to calculate minimum approach distances from
one phase to another. As noted in Appendix B to existing Sec. 1910.269
and in Appendix B to proposed subpart V, the following equation is used
in determining the phase-to-phase maximum transient overvoltage based
on the per unit of the system nominal voltage phase-to-ground crest:
[GRAPHIC] [TIFF OMITTED] TP22OC08.001
Where:
pup = p.u. phase-to-phase maximum transient overvoltage
pug = p.u. phase-to-ground maximum transient overvoltage.
This value was to be used in Equation (1) to calculate the phase-
to-phase minimum approach distance (MAD).
The technical committees responsible for ANSI/IEEE and the National
Electrical Safety Code (NESC, ANSI C2) calculated minimum approach
distances based on these equations. Because OSHA intended to use the
same methodology, it relied on the technical committees' calculations
as they appeared in the two consensus standards and carried those
distances into the proposed standard.
During the most recent revision cycle for ANSI/IEEE Standard 516,
the IEEE technical committee responsible for revising that standard
identified what in their view was an error in the calculations of
phase-to-phase minimum approach distances for nominal voltages 230 kV
and higher. At these voltages, the saturation factor, a, which appears
in Equation (1), varies depending upon the voltage. The value of a
increases with increasing voltage. The NESC subcommittee originally
calculated the phase-to-phase minimum approach distances using a value
for the saturation factor, a, corresponding to the phase-to-ground
maximum transient overvoltage rather than the maximum phase-to-phase
transient overvoltage.\4\ Because the MADs used in OSHA's 2005 proposal
were taken from the consensus standard, OSHA wants to obtain comments
on whether changes are necessary to the tables as proposed.
---------------------------------------------------------------------------
\4\ ANSI/IEEE Standard 516-1987 did not contain distances for
phase-to-phase exposures. The NESC subcommittee derived them by
applying the IEEE equation to the phase-to-phase temporary
overvoltages calculated using Equation (2).
---------------------------------------------------------------------------
The IEEE committee proposed a correction in a draft revised IEEE
Standard 516 (Draft 9).\5\ Table 1 shows the difference
between the minimum approach distances in that draft IEEE Standard 516
and those contained in proposed Sec. 1910.269 Table R-6 and proposed
Subpart V Table V-2 for voltages over 72.5 kV. A subsequent draft from
the IEEE committee (Draft 10) dropped values for voltages with
temporary overvoltages exceeding 1600 kV.\6\ Draft 10 leaves
the determination of these values to ``good engineering judgment.''
---------------------------------------------------------------------------
\5\ This document is available for inspection and copying in the
Docket Office at the address listed in the ADDRESSES section of this
notice.
\6\ This document is also available for inspection and copying
in the Docket Office at the address listed in the ADDRESSES section
of this notice.
Table 1--Comparison of Minimum Approach Distances
----------------------------------------------------------------------------------------------------------------
Distance (m)
-------------------------------------------------------------------
Phase-to-ground exposure Phase-to-phase exposure
Nominal voltage in kilovolts phase-to-phase -------------------------------------------------------------------
Proposed Proposed
Draft IEEE 516 tables R-6 and Draft IEEE 516 tables R-6 and
\1\ V-2 \1\ V-2
----------------------------------------------------------------------------------------------------------------
72.6 to 121................................. 1.01 0.95 1.36 1.29
138 to 145.................................. 1.15 1.09 1.57 1.50
161 to 169.................................. 1.29 1.22 1.85 1.71
230 to 242.................................. 1.71 1.59 2.91 2.27
345 to 362.................................. 2.72 2.59 5.13 3.80
500 to 550.................................. 3.54 3.42 6.89 5.50
[[Page 62944]]
765 to 800.................................. 4.64 4.53 9.35 7.91
----------------------------------------------------------------------------------------------------------------
\1\ Draft 9 of IEEE Standard 516 provides separate minimum approach distances for exposures with and
without tools in the air gap. The distances in the table are for tools in the air gap (called ``minimum tool
insulation distances'' in the IEEE standard.). The NESC minimum approach distances tables are derived from the
distances in IEEE Standard 516 corresponding to exposures with tools in the air gap.
As can be seen from Table 1, the IEEE's proposed approach from
Draft 9 results in a substantial increase in MAD for phase-to-
phase exposures at voltages of 230 kV and higher.
For purposes of the public's consideration of the issues in this
reopening notice, OSHA points out the following technical issues:
1. For voltages over 72.5 kV, the electrical component of the
minimum approach distances \7\ in OSHA's proposal is based on testing
of rod-to-rod gaps performed by 13 laboratories. This testing extends
to approximately 1.6 MV. This voltage is sufficient to cover the
maximum transient overvoltage for all phase-to-ground exposures.
However, it does not extend to the maximum transient overvoltages for
phase-to-phase exposures of voltages 362 kV and higher, as shown in
Table 2.
---------------------------------------------------------------------------
\7\ The electrical component of the minimum approach distance is
called ``minimum tool insulation distance'' or MTID in the IEEE
draft.
Table 2--Maximum Transient Overvoltages
------------------------------------------------------------------------
Maximum transient overvoltage (in
Maximum kV)
System voltage anticipated per- -----------------------------------
(in kV) Vmax unit transient Phase-to-ground Phase-to-phase
overvoltage pu exposure exposure
------------------------------------------------------------------------
362 3.0 1086 1665
552 2.4 1325 2208
800 2.0 2208 2880
------------------------------------------------------------------------
Note: The maximum transient overvoltage for phase-to-ground exposure
equals Vmax x pu. The maximum overvoltage for phase-to-phase exposures
equals Vmax x (pu + 1.6).
In Draft 9, the IEEE committee addressed this issue by
extending the equations used for calculating the minimum air insulation
distance beyond the highest voltage covered by the test data. Other
approaches using the same criteria upon which the minimum approach
distances are based could include: (1) Using available test data for
conductor-to-conductor gaps and converting them to equivalent rod-to-
rod values, and (2) commissioning further tests.
2. IEEE Drafts 9 and 10 also include other
refinements of the method used to calculate minimum approach distances
intended to make the calculations more precise and repeatable. For
example, the saturation factor is now based on equations resulting from
curve fitting the test data rather than from reading the value directly
from a graph of these data.
3. If the minimum approach distances are based on the minimum tool
insulation distance, as is done in the NESC, there would be additional
slight increases in MAD for all voltages of 72.6 kV and higher with
both phase-to-ground and phase-to-phase exposures.
In light of the IEEE committee's draft revisions, OSHA is reopening
the record on the electric power generation, transmission, and
distribution standard to invite comments, evidence, and data on the
limited question of whether the Agency should adopt minimum approach
distances different from those proposed for voltages of 72.6 kV and
higher. The Agency strives to adopt a final rule that is based on sound
and up-to-date engineering, and scientific principles and is
specifically inviting comments on the following questions:
1. Should OSHA adopt MADs that are different from those proposed
for voltages of 72.6 kV and higher and, if so, should it adopt the
distances in Draft 9 or 10 of IEEE Standard 516?
2. Are there methods other than those in Drafts 9 and
10 of IEEE Standard 516 that would be more appropriate in the
calculation of MAD for maximum transient overvoltages beyond existing
data for rod-to-rod gaps?
3. Should MAD for voltages of 72.6 kV and higher be based on the
minimum tool insulation distance as is the case in the 2007 NESC?
4. Should the final rule include separate minimum approach distance
tables for air gaps and for tools as is done in Drafts 9 and
10 of IEEE Standard 516?
OSHA is reopening the record solely on issues related to minimum
approach distances for voltages of 72.6 kV and higher. The record is
not being reopened on any other issue.
List of Subjects in 29 CFR Parts 1910 and 1926
Electric power, Fire prevention, Hazardous substances, Occupational
safety and health, Safety.
Authority and Signature
This document was prepared under the direction of Edwin G. Foulke,
Jr., Assistant Secretary of Labor for Occupational Safety and Health,
U.S. Department of Labor, 200 Constitution Avenue, NW., Washington, DC
20210. It is issued pursuant to sections 4, 6, and 8 of the
Occupational Safety and Health Act of 1970 (29 U.S.C. 653, 655, 657),
[[Page 62945]]
Secretary's Order 5-2007 (72 FR 31160), and 29 CFR Part 1911.
Signed at Washington, DC, this 16th day of October 2008.
Edwin G. Foulke, Jr.
Assistant Secretary of Labor for Occupational Safety and Health.
[FR Doc. E8-25079 Filed 10-21-08; 8:45 am]
BILLING CODE 4510-26-P
