Federal Motor Vehicle Safety Standards; Electric-Powered Vehicles; Electrolyte Spillage and Electrical Shock Protection, 45436-45453 [2011-19216]
Download as PDF
<![CDATA[
45436
Federal Register / Vol. 76, No. 146 / Friday, July 29, 2011 / Rules and Regulations
[Docket No. NHTSA–2011–0107]
202–366–2992) (fax: 202–366–3820),
NCC–112.
The mailing address for these officials
is: National Highway Traffic Safety
Administration, 1200 New Jersey
Avenue, SE., Washington, DC 20590.
SUPPLEMENTARY INFORMATION:
RIN 2127–AK80
Table of Contents
DEPARTMENT OF TRANSPORTATION
National Highway Traffic Safety
Administration
49 CFR Part 571
Federal Motor Vehicle Safety
Standards; Electric-Powered Vehicles;
Electrolyte Spillage and Electrical
Shock Protection
National Highway Traffic
Safety Administration (NHTSA),
Department of Transportation (DOT).
ACTION: Final rule; response to petitions
for reconsideration.
AGENCY:
This document responds to
petitions for reconsideration of a final
rule issued by this agency on June 14,
2010. This final rule amended the
electrical shock protection requirements
to facilitate the development and
introduction of fuel cell vehicles (a type
of electric-powered vehicle) and the
next generation of hybrid and battery
electric powered vehicles. This
document addresses issues raised in the
petitions for reconsideration relating to
the scope and applicability of the
standard, the definitions in the
standard, the retention requirements for
electric energy storage/conversion
systems, the electrical isolation
requirements, the test specifications and
requirements for electrical isolation
monitoring, the state-of-charge of
electric energy storage devices prior to
the crash tests, a proposed protective
barrier compliance option for electrical
safety, the use of alternative gas to crash
test hydrogen fuel cell vehicles, and a
proposed low-energy compliance option
for electrical safety.
DATES: The effective date of this final
rule is September 1, 2011 with optional
early compliance.
Petitions for reconsideration: Petitions
for reconsideration of this final rule
must be received not later than
September 12, 2011.
ADDRESSES: Petitions for reconsideration
of this final rule must refer to the docket
and notice number set forth above and
be submitted to the Administrator,
National Highway Traffic Safety
Administration, 1200 New Jersey
Avenue, SE., Washington, DC 20590.
FOR FURTHER INFORMATION CONTACT: For
technical issues: Ms. Shashi Kuppa,
Office of Crashworthiness Standards
(telephone: 202–366–3827) (fax: 202–
493–2990), NVS–113.
For legal issues: Mr. Jesse Chang,
Office of the Chief Counsel (telephone:
jlentini on DSK4TPTVN1PROD with RULES
SUMMARY:
VerDate Mar<15>2010
16:04 Jul 28, 2011
Jkt 223001
I. Background—June 14, 2010 Final Rule
II. Petitions for Reconsideration
III. Summary of Revisions to the June 14,
2010 Final Rule
IV. Agency Response and Rationale
a. Application
b. Definitions
c. Electric Energy Storage/Conversion
System Retention
d. Electrical Safety
e. Electrical Isolation Monitoring
f. Electric Energy Storage Device State-ofCharge
g. Physical Barrier Compliance Option for
Electrical Safety
h. Use of Alternative Gas for Testing
Hydrogen Fuel Cell Vehicles
i. Low-Energy Compliance Option for
Electrical Safety
V. Rulemaking Analyses and Notices
VI. Regulatory Text
I. Background—June 14, 2010 Final
Rule
On June 14, 2010, NHTSA issued a
final rule which amended the electrical
shock protection requirements of
Federal Motor Vehicle Safety Standard
(FMVSS) No. 305, ‘‘Electric-powered
vehicles; electrolyte spillage and
electrical shock protection,’’ to facilitate
the development and introduction of
fuel cell vehicles, a type of electricpowered vehicle, and the next
generation of hybrid and battery electric
powered vehicles (75 FR 33515, NHTSA
Docket No. 2010–0021). The final rule
revised the agency’s standard regulating
electrolyte spillage and electrical shock
protection for electric-powered vehicles
to align it more closely with the April
2005 version of the Society of
Automotive Engineers (SAE) J1766—
‘‘Recommended Practice for Electric and
Hybrid Electric Vehicle Battery Systems
Crash Integrity Testing.’’
This rule also provided greater
flexibility by allowing manufacturers to
meet the requirements of FMVSS No.
305 by designing their electrically
powered vehicles so that, in the event
of a crash, the electric energy storage,
conversion, and propulsion systems are
either electrically isolated from the
vehicle’s chassis or their voltage is
below specified levels considered safe
from electric shock hazards. Since the
physiological impacts of direct current
(DC) are less than those of alternating
current (AC), the final rule specified
lower electrical isolation requirements
for certain DC components (100 ohms/
PO 00000
Frm 00040
Fmt 4700
Sfmt 4700
volt) than for AC components (500
ohms/volt).
In addition, the final rule included
new definitions, made changes to
existing definitions of terms used in the
standard, changed the energy storage/
conversion device retention
requirements, specified a low voltage
option for achieving electrical safety,
and required monitoring of the isolation
resistance of DC high voltage sources
that comply with the 100 ohms/volt
electrical isolation requirement. The
agency also established an effective date
on September 1 in the year after the
final rule was published (or September
1, 2011) with optional early compliance.
II. Petitions for Reconsideration
Subsequently, NHTSA received
petitions for reconsideration of the June
14, 2010 final rule from the Alliance of
Automobile Manufacturers (Alliance),1
Technical Affairs Committee of the
Association of International Automobile
Manufacturers, Inc. (AIAM) 2 and Honda
Motor Co., Ltd. (Honda). Ford Motor
Company (Ford) also presented an
analysis to the agency in support of the
Alliance’s petition for reconsideration
regarding the issue of electric energy
storage system state-of-charge prior to
the crash tests specified in the
standard.3 In addition, on December 21,
2010, the Alliance, AIAM, and Honda
submitted a joint letter as
supplementary information to their
petitions for reconsideration stating
their support for the definitions used in
the draft documents on electrical safety
for a forthcoming global technical
regulation (GTR) on hydrogen fuel cell
vehicle safety.
The petitioners generally sought
increased clarity by raising issues
1 The Alliance is a trade association whose
members are: BMW Group, Chrysler Group LLC,
Ford Motor Company, General Motors LLC, Jaguar
Land Rover, Mazda, Mercedes-Benz USA,
Mitsubishi Motors, Porsche, Toyota, and
Volkswagen.
2 The AIAM petition stated it is a trade
association whose Technical Affairs Committee
members include: American Honda Motor Co.,
American Suzuki Motor Corp., Aston Martin
Lagonda of North America, Inc., Ferrari North
America, Inc., Hyundai Motor America, Isuzu
Motors America LLC, Kia Motors America, Inc.,
Mahindra & Mahindra Ltd., Maserati North
America, Inc., McLaren Automotive Ltd., Nissan
North America, Inc., Peugeot Motors of America,
Subaru of America, ADVICS North America, Inc.,
Delphi Corporation, Denso International America,
Inc., and Robert Bosch Corporation. In January
2011, AIAM was renamed as the Association of
Global Automakers (Global Automakers).
Nonetheless, our response to petitions of the final
rule will still refer to AIAM.
3 Ford presented an analysis of the state-of-charge
of the energy storage system prior to the crash tests
in a meeting with NHTSA personnel on May 26,
2010. This presentation was posted to the Docket
No. NHTSA–2010–0021 on September 1, 2010.
E:\FR\FM\29JYR1.SGM
29JYR1
Federal Register / Vol. 76, No. 146 / Friday, July 29, 2011 / Rules and Regulations
jlentini on DSK4TPTVN1PROD with RULES
regarding the definitions, test
specifications, and performance
requirements in this rule. Specifically,
the petitioners raised questions
regarding the applicability and scope of
the standard, the definitions of terms
used, the electric energy storage/
conversion system retention
requirements, the electrical isolation
requirements, the requirements and test
specifications for electrical isolation
monitoring systems, the electric energy
storage device state-of-charge, the
protective barrier as a compliance
option for electrical safety, and the use
of alternative gas for testing hydrogen
fuel cell vehicles.
III. Summary of Revisions to the June
14, 2010 Final Rule
This document responds to all the
petitions for reconsideration of the June
14, 2010 final rule. Specifically, this
final rule makes the following changes
to the June 14, 2010 final rule:
• Revises the ‘‘Application’’ section
to indicate that the standard applies
only to vehicles that use high voltage
electrical components for propulsion
power rather than to any vehicle that
has high voltage electrical components.
• Clarifies the definitions used in the
June 14, 2010 final rule for electrical
isolation, electric energy storage/
conversion system, electric energy
storage device, propulsion system, and
high voltage source.
• Adds further clarity by including
new definitions for automatic
disconnect, electric energy storage/
conversion device, electrical chassis,
and electric power train.
• Revises the application of retention
requirements from energy storage/
conversion ‘‘systems’’ to energy storage/
conversion ‘‘devices.’’
• Clarifies the electric energy storage/
conversion device retention
requirements to indicate that during and
after the test, the device(s) shall remain
attached to the vehicle by at least one
component anchorage, bracket, or any
structure that transfers loads from the
device to the vehicle structure and those
located outside the occupant
compartment shall not enter the
occupant compartment.
• Clarifies the electrical safety
requirements to specify that AC high
voltage sources with electrical isolation
monitoring require 500 ohms/volt
electrical isolation.
• Specifies the voltage measurement
locations for high voltage sources with
and without automatic disconnects in
the test procedures for determining
electrical safety.
• Revises the electrical isolation
monitoring requirement by deleting the
VerDate Mar<15>2010
16:04 Jul 28, 2011
Jkt 223001
term ‘‘continuous’’ in ‘‘continuous
monitoring’’ and including a range in
resistance of the external resistor
selected in the test procedure to
evaluate the performance of the
monitoring system.
• Clarifies the specification for the
state-of-charge of electric energy storage
devices before the crash tests to be at the
maximum state-of-charge in accordance
with the vehicle manufacturer’s
recommended charging procedures, as
stated in the vehicle owner’s manual or
on a label permanently affixed to the
vehicle, or at 95 percent of the
maximum capacity of the electric energy
storage device if no such
recommendation is made.
• Revises the regulatory text and
Figures 1–5 to utilize the new terms
added to the definitions section.
IV. Agency Response and Rationale
After reviewing the petitions for
reconsideration, NHTSA is responding
to each issue raised by the petitioners as
follows.
a. Application
The June 14, 2010 final rule defined
the scope of FMVSS No. 305 by stating
the following in paragraph S3
Application:
S3. Application. This standard applies to
passenger cars, and to multipurpose
passenger vehicles, trucks, and buses that
have a GVWR of 4,536 kg or less, that use
electrical components with working voltages
more than 60 volts direct current (VDC) or 30
volts alternating current (VAC), and whose
speed attainable over a distance of 1.6 km on
a paved level surface is more than 40 km/h.
Both the Alliance and the AIAM
noted that in section ‘‘S3 Application’’
of the final rule, the agency omitted the
word ‘‘propulsion’’ and that this was
not consistent with the language in the
NPRM.4 Both organizations argued that
the omission of the word ‘‘propulsion’’
could be interpreted to encompass all
electrical systems that are not within the
scope of FMVSS No. 305 (e.g. high
intensity discharge (HID) headlamps,
engine ignition systems, fuel injectors,
etc).
The Alliance proposed that the scope
be remedied by adding the word
‘‘propulsion’’ in the application section,
S3. The AIAM indicated in its petition
that it supported the language proposed
by the Alliance. The language proposed
by the Alliance is as follows:
S3 Application. This standard applies to
passenger cars, and to multipurpose
passenger vehicles, trucks and buses with a
GVWR of 4536 kg or less, that use electrical
4 72 FR 57266; Notice of Proposed Rulemaking;
October 9, 2007.
PO 00000
Frm 00041
Fmt 4700
Sfmt 4700
45437
propulsion components with working
voltages more than 60 volts direct current
(VDC) or 30 volts alternating current (VAC),
and whose speed attainable over a distance
of 1.6 km on a paved level surface is more
than 40 km/h. (emphasis in the original)
NHTSA’s Response: We agree with
the Alliance that by omitting the word
‘‘propulsion’’ in S3 of the final rule, the
standard encompasses vehicles and
electrical systems that were not
intended for application of FMVSS No.
305. Since the agency is not aware of
any cases of injuries/fatalities from
shock in non-electrically powered
vehicles with other high voltage
components such as HID headlamps,
ignition systems, or fuel injectors, this
final rule adopts the language for S3
Application as proposed by the
Alliance. This new version of the
regulatory text ensures that FMVSS No.
305 will not extend to the
aforementioned vehicles and vehicle
components for which the standard was
not intended to apply.
b. Definitions
The June 14, 2010 final rule adopted
new definitions into FMVSS No. 305. In
a joint letter submitted by the Alliance,
AIAM, and Honda, the organizations
acknowledged that while the current
FMVSS No. 305 definitions were based
on SAE J1766, the subsequent
promulgation of FMVSS No. 305 and
the development of an international
GTR on hydrogen fuel cell vehicle safety
have largely rendered aspects of the
SAE standard obsolete. The
organizations requested that the agency
incorporate, into FMVSS No. 305, the
definitions contained in the draft
electrical safety requirements developed
by the Electric Safety (ELSA) working
group in September 2010 as part of the
draft GTR. Given this request from the
aforementioned organizations, the rapid
development of technology in electrical
and fuel cell vehicles resulting in
numerous changes in terminology and
their associated definitions, and
significant uncertainty among the
relevant stakeholders as to the proper
interpretation of many of the definitions
adopted by the June 14, 2010 final rule,
today’s final rule seeks to clarify and
update many of the definitions through
additional language and/or adopting
similar language from the draft ELSA
electrical safety document (henceforth
referred to as the ELSA document)
where appropriate.5 In the following
5 Electrical Safety Provisions for Vehicles Post
Crash ELSA–8–05 Rev. 01 (Draft agreed during 8th
ELSA Meeting, Aug 31–Sept 2, 2010) https://
www.unece.org/trans/doc/2010/wp29grsp/ELSA-805r1e.pdf.
E:\FR\FM\29JYR1.SGM
29JYR1
45438
Federal Register / Vol. 76, No. 146 / Friday, July 29, 2011 / Rules and Regulations
sections, we will address each of the
definitions added or amended by
today’s final rule in turn.
jlentini on DSK4TPTVN1PROD with RULES
1. Automatic Disconnect
One appropriate area for adopting
similar language from the ELSA
document is the definition for
‘‘automatic disconnect.’’ Since the June
14, 2010 final rule did not define
‘‘automatic disconnect,’’ the agency is
concerned that it may result in
ambiguity regarding the location of
voltage measurements taken pursuant to
paragraph S7.6.1 (as further discussed
later in this document). Therefore,
today’s final rule includes a definition
for automatic disconnect, derived from
the ELSA document, which states that
‘‘automatic disconnect’’ means a device
that when triggered, conductively
separates a high voltage source from the
electric power train or the rest of the
electric power train.
2. Electrical Isolation
In the final rule, we defined
‘‘Electrical isolation’’ as ‘‘the electrical
resistance between the vehicle high
voltage source and any vehicle
conductive structure.’’ The Alliance
stated that the definition for ‘‘electrical
isolation’’ as defined in the final rule
could present difficulties because ‘‘any
vehicle conductive structure’’ could be
interpreted to include the high voltage
source itself, and a high voltage source
cannot be isolated from itself. The
Alliance, therefore, petitioned to revise
the definition so that the electrical
isolation is between the vehicle high
voltage source and the ‘‘vehicle chassis
electricity-conducting structure.’’
NHTSA’s Response: The agency
agrees that that the language ‘‘any
conductive structure’’ should be
clarified to indicate which vehicle
components are required to be isolated
from the high voltage source. However,
we decline to adopt the Alliance’s
proposed term, ‘‘vehicle chassis
electricity-conducting structure,’’ since
it also lacks sufficient clarification on
which vehicle components will be
included by this term. For example, it
is unclear whether the term includes
other conducting structures in the
vehicle such as the enclosures of high
voltage sources. To address this issue,
this final rule clarifies what the high
voltage source is electrically isolated
from by including a definition for a new
term that has been proposed in the draft
ELSA document. Based on the language
of the ELSA document, a definition for
‘‘electrical chassis’’ is included in
today’s final rule as follows:
Electrical chassis means conductive parts
of the vehicle whose electrical potential is
VerDate Mar<15>2010
16:04 Jul 28, 2011
Jkt 223001
taken as reference and which are: (1)
conductively linked together, and (2) not high
voltage sources during normal vehicle
operation.
Since this definition of electrical
chassis includes vehicle designs with
multiple electrical chassis, this final
rule clarifies the definition of electrical
isolation to mean the electrical
resistance between a given high voltage
source and any electrical chassis of the
vehicle. Further, in order to be
consistent with the manner in which
electrical isolation is determined in
S7.6.6 and S7.6.7 of the electrical
isolation test procedure and with the
units of electrical isolation specified in
S5.3(a), today’s final rule also clarifies
the definition of electrical isolation of a
high voltage source to mean the
electrical isolation resistance of the high
voltage source divided by the working
voltage of the high voltage source.
Applying these corrections, along with
the new definition of electrical chassis,
today’s final rule amends the definition
for electrical isolation to read as follows:
Electrical isolation of a high voltage source
in the vehicle means the electrical resistance
between the high voltage source and any of
the vehicle’s electrical chassis divided by the
working voltage of the high voltage source.
The agency believes the changes made
in today’s final rule address the
Alliance’s concern about the broad term
‘‘any vehicle conductive structure.’’
Specifically, this definition ensures that
the term ‘‘vehicle conductive structure’’
is not construed to include the high
voltage source itself as the new
definition for ‘‘electrical chassis’’
explicitly excludes high voltage sources.
In addition, the use of these definitions
more closely aligns FMVSS No. 305
with the definitions proposed by the
ELSA working group and clarifies what
types of components would be
considered part of the chassis. For
example, under these definitions, the
electrical chassis includes the
enclosures of the high voltage sources
which are conductively linked to other
conductive parts of the vehicle whose
electrical potential is taken as a
reference.
3. Electric Energy Storage/Conversion/
Power Generating System & Electric
Energy Storage Device
Before the NPRM in this current
rulemaking, FMVSS No. 305 contained
a definition for the term ‘‘Battery system
component.’’ In the NPRM, the agency
proposed replacing the definition of
‘‘Battery system component’’ with
‘‘Energy storage system.’’ The agency
changed the definition in the final rule
after considering the joint Alliance/
PO 00000
Frm 00042
Fmt 4700
Sfmt 4700
AIAM comment to the NPRM to include
‘‘energy conversion system’’ as part of
the definition for ‘‘Energy storage
system.’’ In their comment, the
Alliance/AIAM stated that fuel cell
systems were conversion systems and
should also comply with the retention
requirements. NHTSA agreed and
redefined ‘‘Energy storage system’’ as
‘‘Electric energy storage/conversion/
power generating system.’’ The term
‘‘power generating system’’ was also
included to align FMVSS No. 305 more
closely with the terminology used in
SAE J1766. Thus, the June 14, 2010 final
rule defined ‘‘Electric Energy Storage/
Conversion/Power Generating System’’
as follows:
Electric energy storage/conversion/power
generating system means the components
comprising, but not limited to, the vehicle’s
high voltage battery system, capacitor system,
or fuel cell system, and rechargeable energy
storage systems. These include, but are not
limited to, the battery or capacitor modules,
interconnects, venting systems, battery or
capacitor restraint devices, and electric
energy storage boxes or containers that hold
the individual battery or capacitor modules.
Hydrogen system components of fuel cell
vehicles, such as the hydrogen tanks and
hydrogen tubes, are not included in the
electric energy storage/conversion system.
We received multiple petitions
requesting that the agency reconsider
the ‘‘Electric energy storage/conversion/
power generating system’’ definition.
The Alliance stated that this definition
is overly broad and includes energy
storage systems beyond those used for
propulsion power. The Alliance
recommended that the definition be
modified to utilize the following text:
Electric energy storage/conversion/
power generating system ‘‘means the
electric energy sources for the
propulsion system comprising, but not
limited to, the vehicle’s high voltage
battery system * * *’’ (emphasis in
original).
The AIAM and Honda had further
concerns about the definition. The
AIAM stated that the definition is not
used consistently throughout the
standard or even within the definition
itself. For example, the AIAM noted that
the last sentence of the definition for
electrical energy storage/conversion/
power generating system (which refers
to hydrogen system components of fuel
cell vehicles) is only applicable to the
electric energy storage or conversion
system parts of the definition and not to
the power generating system portion.
Honda stated that the combined
definition may cause confusion to the
reader.
Further, both the AIAM and Honda
stated that various requirements in
E:\FR\FM\29JYR1.SGM
29JYR1
jlentini on DSK4TPTVN1PROD with RULES
Federal Register / Vol. 76, No. 146 / Friday, July 29, 2011 / Rules and Regulations
FMVSS No. 305 apply only to portions
of the electric energy storage/
conversion/power generating system
definition, creating confusion regarding
the applicability of various
requirements in the standard. The
AIAM and Honda refer to fuel cell
modules as an example of this potential
confusion. They noted that the retention
requirements in S5.2, as written, are
applicable only to the electric energy
storage system and electric energy
conversion system but are not
applicable to the electric power
generating system. According to SAE
J1766 (April, 2005), the term ‘‘power
generating system components’’ is
defined as ‘‘the components comprising
the high voltage power generating
system in an Electric, Fuel Cell or
Hybrid vehicle. These include, but are
not limited to, generators, fuel cell
modules, DC/DC converters and
interconnects.’’ The AIAM and Honda
stated that if the SAE definition is used
to determine the meaning of ‘‘power
generating system’’ for purposes of S5.2
retention requirements, it could be
concluded that fuel cell modules are
exempt because S5.2 does not list
‘‘power generating system’’ as requiring
compliance with the retention
requirements. The AIAM and Honda do
not believe that the agency intended to
exclude fuel cell modules from the
retention requirements, considering the
potential occupant injury risk in a crash
if fuel cell modules became unattached.
For clarity, both the AIAM and Honda
petitioned that the terms ‘‘Electric
energy storage system,’’ ‘‘Electric energy
conversion system’’ and ‘‘Electric power
generating system’’ be defined
separately.
NHTSA’s Response: We agree with
petitioners that the ‘‘Electric energy
storage/conversion/power generating
system’’ definition should be clarified in
order to avoid confusion as to the
applicability of various requirements in
FMVSS No. 305. In order to accomplish
this task, today’s final rule utilizes three
separate definitions. First, it renames
and makes adjustments to the language
in the ‘‘Electric energy storage/
conversion/power generating system’’
definition in order to reference the
components that comprise the entire
‘‘Electric energy storage/conversion
system.’’ Second, today’s final rule also
adds a new definition for ‘‘Electric
energy storage/conversion device’’ in
order to help distinguish the instances
in which the various requirements of
FMVSS No. 305 are to apply to an entire
system as opposed to only component
devices. Finally, this rule also retains
the ‘‘Electric energy storage device’’
VerDate Mar<15>2010
16:04 Jul 28, 2011
Jkt 223001
definition with minor revisions in order
to clarify the instances in which the test
specifications of this rule apply to the
electric energy storage devices alone.
The agency also agrees with the
Alliance petition that the definition for
‘‘electric energy storage/conversion/
power generating system’’ should be
specific to systems used for vehicle
propulsion in order to distinguish them
from other electric energy storage
systems such as the auxiliary battery
that is present on many hybrid/electric
vehicles and is currently not subject to
the retention requirements since it is
typically of low mass and does not pose
a safety hazard in the existing fleet.
Thus, we have made the appropriate
modifications to the three
aforementioned definitions to indicate
that the devices or components covered
by each definition are used for vehicle
propulsion.
In order to further add clarity to this
definition, this final rule removes the
reference to the term, ‘‘power generating
systems,’’ from the June 14, 2010 final
rule definition of ‘‘Electric energy
storage/conversion/power generating
system.’’ As ‘‘power generating
systems’’ was included in the June 14,
2010 final rule definition in order to
more closely align FMVSS No. 305 with
the (now obsolete) SAE Standard J1766,
the agency believes that there is no
longer a purpose for including ‘‘power
generating systems’’ in the ‘‘Electric
energy storage/conversion/power
generating system’’ definition. Thus,
today’s final rule simply defines
‘‘Electric energy storage/conversion
system.’’
In addition, we agree with the AIAM
that the last sentence of the ‘‘Electric
energy storage/conversion/power
generating system’’ definition in the
June 14, 2010 final rule can cause
confusion. We believe that the last
sentence of that definition, which states
that ‘‘[h]ydrogen system components of
fuel cell vehicles, such as the hydrogen
tanks and hydrogen tubes, are not
included in the electric energy storage/
conversion system,’’ is superfluous.
Thus, in further advancing the goal of
clarity in the ‘‘Electric energy storage/
conversion system’’ definition, we have
deleted the aforementioned sentence.
Under the definition in today’s final
rule, fuel cells are a type of energy
conversion system and the agency will
continue to refer to high voltage
batteries, capacitors, and fuel cell
systems as ‘‘energy storage/conversion
systems.’’
Thus, the final rule defines ‘‘Electric
energy storage/conversion system’’ as
follows:
PO 00000
Frm 00043
Fmt 4700
Sfmt 4700
45439
Electric energy storage/conversion system
means an assembly of electrical components
that stores or converts electrical energy for
vehicle propulsion. This includes, but is not
limited to, high voltage batteries or battery
packs, fuel cell stacks, rechargeable energy
storage systems, capacitor modules, inverters,
interconnects, and venting systems.
Additionally, today’s final rule adds a
new definition for ‘‘Electric energy
storage/conversion device.’’ We take
note that the retention requirements of
S5.2 of the June 14, 2010 final rule
apply to all components that fall under
the broader ‘‘Electric energy storage/
conversion system’’ definition and that
petitioners asked for clarification to the
‘‘Electric energy storage/conversion
system’’ definition, in part, to clarify the
specific components that will be subject
to the retention requirements of
paragraph S5.2. As further discussed
later in this document, petitioners are
concerned that ‘‘energy storage/
conversion systems’’ can include
interconnects and venting systems that
are typically of low mass and need not
be included in the retention
requirements because they are not a
safety risk. Thus, to make this
distinction, today’s final rule modifies
paragraph S5.2 to utilize the definition
for ‘‘electric energy storage/conversion
device’’ and defines this term as
follows:
Electric energy storage/conversion device
means a high voltage source that stores or
converts energy for vehicle propulsion. This
includes, but is not limited to, a high voltage
battery or battery pack, fuel cell stack,
rechargeable energy storage device, and
capacitor module.
Today’s final rule also retains and
amends the definition of ‘‘Electric
energy storage device’’ from the June 14,
2010 final rule. The June 14, 2010 final
rule defined ‘‘Electric energy storage
device’’ as follows:
Electric energy storage device means a high
voltage source that can store energy, such as
a battery or capacitor modules.
The term, ‘‘Electric energy storage
device,’’ is used in the regulatory text to
specify the state of charge of electric
energy storage devices before the
vehicle crash test. While closely related
to the term ‘‘Electric energy storage/
conversion device,’’ it does not
encompass conversion devices such as
fuel cell stacks. Today’s final rule makes
minor revisions to this definition in
order to add clarity and consistency
with the two other definitions discussed
in this section by specifying that the
electric energy storage devices under
consideration are used for vehicle
propulsion. Thus, the definition of
electric energy storage device in today’s
final rule is amended as follows:
E:\FR\FM\29JYR1.SGM
29JYR1
45440
Federal Register / Vol. 76, No. 146 / Friday, July 29, 2011 / Rules and Regulations
Electric energy storage device means a high
voltage source that stores energy for vehicle
propulsion. This includes, but is not limited
to, a high voltage battery or battery pack,
rechargeable energy storage device, and
capacitor module.
Paragraphs S1 and S2 of today’s final
rule have also been amended to reflect
these new definitions.
4. High Voltage Source
The June 14, 2010 final rule included
a definition of ‘‘high voltage source’’
which is reproduced below:
jlentini on DSK4TPTVN1PROD with RULES
High voltage source means any electric
component that has a working voltage greater
than 30 VAC or 60 VDC.
The Alliance stated that in common
usage, a ‘‘voltage source’’ is a
component capable of generating or
storing electrical potential energy. It
argued that under the current definition,
connectors and wiring could be
construed as voltage sources even
though they are not capable of
generating or storing electrical energy.
The Alliance petitioned that the
definition of ‘‘high voltage source’’ be
revised to include ‘‘any electric
component that is capable of generating
or storing a voltage greater than 30 VAC
or 60 VDC.’’
NHTSA’s Response: We agree with
the Alliance that the current definition
of ‘‘high voltage source’’ should be
clarified. However, we cannot agree
with the petitioner’s proposal to limit
the definition of high voltage sources to
only those components that are capable
of generating or storing electrical
energy. Through the definition included
in the June 14, 2010 final rule, the
agency did intend to apply the electrical
safety requirements to high voltage
components, including wiring and
connectors that are part of the vehicle’s
electric power train to ensure
comprehensive electric shock
protection.
However, we acknowledge that the
definition in the June 14, 2010 final rule
may not sufficiently distinguish the
components included by the ‘‘high
voltage source’’ definition from those
that are not included. To clarify our
intent today’s final rule defines a high
voltage source as ‘‘any electric
component contained in the electric
power train or conductively connected
to the electric power train that has a
working voltage greater than 30 VAC or
60 VDC (emphasis added).’’
To further clarify this new definition,
today’s final rule adds a definition for
‘‘electric power train’’ stating that it
refers to ‘‘an assembly of electrically
connected components which includes,
but is not limited to, electric energy
VerDate Mar<15>2010
16:04 Jul 28, 2011
Jkt 223001
storage/conversion systems and
propulsion systems.’’ The definition of
‘‘electrical energy storage/conversion
system’’ is updated as described above.
Further, today’s final rule makes minor
revisions to the definition of
‘‘propulsion system’’ to mean ‘‘an
assembly of electric or electromechanical components or circuits that
propel the vehicle using the energy that
is supplied by a high voltage source.
This includes, but is not limited to,
electric motors, inverters/converters,
electronic controllers, and associated
wire harnesses and connectors, and
coupling systems for charging
rechargeable energy storage systems.’’
These definitions adopt similar
language from the Definitions and the
General sections of the ELSA document
in order to both address the Alliance,
AIAM and Honda’s suggestion that the
agency adopt the ELSA definitions
where appropriate and to more clearly
define the components that are included
under the definition of ‘‘high voltage
source.’’
c. Electric Energy Storage/Conversion
System Retention
In the NPRM, NHTSA proposed
adjusting the ‘‘Battery retention’’
requirements of paragraph S5.2 to
properly reflect the additional energy
storage devices that the updated
standard intended to cover. The
adjustment to paragraph S5.2
accomplished this goal by proposing to
replace the word ‘‘battery’’ with the
words ‘‘energy storage device’’ in S5.2
and adjust other portions of the
regulatory text accordingly.
In the final rule, we amended the
regulatory text based on the
considerations in the NPRM and in
response to additional information from
a March 9, 2009 interpretation request
from Hyundai. Hyundai stated that the
requirements of S5.2 allowed a battery
module located outside the passenger
compartment to become dislodged as
long as it does not enter the occupant
compartment, while a module that is
located within the occupant
compartment must simply remain in the
location in which it is installed.
Hyundai stated that this may not
properly address the intent of the
standard in some circumstances.6 It
argued that in vehicles such as sport
utility vehicles (SUV) or station wagons,
a battery module located inside the
occupant compartment that moves
during impact due to the deformation of
the floor but remains firmly attached to
its mounting, would technically fail the
6 65 FR 57985, FMVSS No. 305 Final Rule,
September 27, 2000.
PO 00000
Frm 00044
Fmt 4700
Sfmt 4700
retention requirement even though it
would not pose a projectile hazard.
The agency elected to respond to
Hyundai’s interpretation request in the
June 14, 2010 final rule because the
NPRM in this rulemaking had already
proposed to amend the language of S5.2.
Thus, in the final rule, the agency
responded to that interpretation request
stating
‘‘The agency agrees that battery modules
located inside the occupant compartment
technically may move a small amount from
the location from which they are installed
during the impact tests. The agency also
agrees that battery modules located outside
the occupant compartment that partially
move into the occupant compartment
because of structural deformation of the
vehicle structure do not impose a projectile
hazard provided that they remain attached to
the mounting structure.7 Therefore, the
agency concurs that battery modules located
outside the occupant compartment should be
treated in the same manner as those located
inside the occupant compartment, provided
that they remain attached to their
anchorages.’’
Accordingly, the June 14, 2010 final
rule revised the regulatory text to read
as follows:
S5.2 Electric energy storage/conversion
system retention. All components of the
electric energy storage/conversion system
must be anchored to the vehicle. All
component anchorages, including any
brackets or structures that transfer loads from
the component to the vehicle structure, shall
remain attached to the vehicle structure at all
attachment locations during and after testing
performed pursuant to the procedures of S6
of this standard.
In its petition for reconsideration of
the June 14, 2010 final rule, the Alliance
stated that the final rule’s specification
that all component anchorages, shall
remain attached to the vehicle structure
at all attachment locations is an overly
broad requirement that goes beyond the
intent of assuring that battery system
components do not become separated
from the vehicle. The Alliance stated
that this language could be interpreted
as prohibiting a plastic tie-wrap used to
position a wiring harness to the vehicle
from severing in a crash, a requirement
that is neither practicable nor necessary.
The Alliance and the AIAM further
stated that some electric energy storage/
conversion systems, especially those
which are located in the engine
compartment are protected from serious
damage resulting from the collision by
absorbing the energy into deforming or
even breaking component mountings.
The Alliance stated that this was
analogous to other energy management
strategies, such as allowing steering
7 75
E:\FR\FM\29JYR1.SGM
FR 33523.
29JYR1
jlentini on DSK4TPTVN1PROD with RULES
Federal Register / Vol. 76, No. 146 / Friday, July 29, 2011 / Rules and Regulations
columns mountings to deform and break
to keep the steering column away from
the driver of a vehicle during a severe
crash. The Alliance stated that a battery
pack could be mounted to the vehicle at
a dozen attachment points, and the fact
that one of these attachments severs
during a crash test would be
inconsequential to the secure
attachment of the battery pack to the
vehicle, yet violate the language of the
final rule. The AIAM stated that these
system retention provisions may, in
some respects, be unnecessarily design
restrictive and potentially contrary to
the interests of safety because rather
than broadly mandating that the battery
remain attached to the vehicle, the
regulatory text places undue emphasis
on the condition of individual
anchorages, brackets and structures.
Both the AIAM and Honda further
argued that the intent of S5.2 was to
ensure that the battery modules would
not become unattached and become
flying projectiles in a crash or
subsequent rollover. Each referenced the
September 27, 2000 final rule
establishing FMVSS No. 305 8 where the
agency stated, ‘‘We note that the intent
of the proposed requirements in S5.2
was to ensure that the battery modules
would not become unattached and
become flying projectiles in a crash or
subsequent rollover.’’ The AIAM stated
that this regulatory goal is best served
by a requirement that broadly focuses
on the overall condition of the battery
module (whether it remains attached to
the vehicle and has not intruded into
the passenger compartment) rather than
the condition of the individual
anchorages.
Finally, the AIAM and Honda also
stated that there are many smaller
components that paragraph S5.2 in the
June 14, 2010 final rule applies to, such
as ducts or vents, which may become
unattached. They argued that the
occupant injury risk from such
components of the energy storage/
conversion system is very low, given
their small mass and that there are no
comparable requirements for internal
combustion engine (ICE) vehicles. The
AIAM and Honda stated that in order to
exclude low mass components of the
energy storage/conversion system, such
as ducts and vents, the retention
requirements should apply only to
energy storage/conversion devices
rather than to energy storage/conversion
systems.
Each of the petitioners had different
strategies for amending the
requirements for electric energy storage/
conversion system retention. The
8 65
FR 57985.
VerDate Mar<15>2010
16:04 Jul 28, 2011
Jkt 223001
Alliance petitioned that in order to
avoid unnecessary design limitations
while achieving protection from both
physical damage and electrical shock,
the following language be adopted for
S5.2 of FMVSS No. 305:
‘‘The following requirements shall be met
during and after testing performed pursuant
to the procedures of S6 of this standard:
1. Energy storage/conversion system
components shall remain secured to the
vehicle, and
2. For energy storage/conversion system
components located outside the passenger
compartment, such components shall not
enter the passenger compartment airspace.’’
The Alliance also requested that if the
agency does not agree with the proposed
language, the agency revert to the
previous language of S5.2.
The AIAM petitioned the agency to
amend S5.2 to read as follows:
‘‘S5.2 Electric energy storage/conversion
device(s) retention. Electric energy storage/
conversion devices must remain attached to
the vehicle during and after testing
performed pursuant to the procedures of S6
of this standard.’’
Honda petitioned to amend S5.2 as
follows:
‘‘S5.2 Electric energy storage/conversion
devices(s) retention. The electric energy
storage/conversion device(s) must remain
attached to the vehicle by anchorages,
brackets, or structures that transfer loads
from the device(s) to the vehicle structure
during and after testing performed pursuant
to the procedures of S6 of this standard.’’
NHTSA’s Response: We agree with
the comments from the Alliance, AIAM,
and Honda suggesting that the changes
to the retention requirement in the June
14, 2010 final rule may be overly broad.
We acknowledge that increased crash
protection for energy storage/conversion
systems can be achieved through the
deformation or breaking of certain
component mounting/anchorages to
absorb the crash energy. We further
acknowledge that the language in the
June 14, 2010 final rule can be
construed to include plastic tie-wraps
used to position a wiring harness which
are not consequential towards the
overall condition of the energy storage/
conversion systems.
However, we decline to adopt the
regulatory text proposed by petitioners
because we are concerned with ensuring
that the final standard is clear and
objective. Thus, the agency does not
believe that the proposed language
changes from the AIAM and the
Alliance are appropriate as they require
that the electric energy storage/
conversion devices remain attached
without offering any specifics on how
the agency would distinguish between a
device that has ‘‘remained attached’’
PO 00000
Frm 00045
Fmt 4700
Sfmt 4700
45441
and one that has not. The regulatory text
proposed by Honda offers more
information on what constitutes
‘‘remaining attached’’ by indicating that
the electric energy storage/conversion
device must remain attached via
‘‘anchorages, brackets, or structures that
transfer loads from the device(s) to the
vehicle.’’ However, this approach
remains unclear as it does not specify
how many anchorages, brackets, or
structures that transfer load must
remain attached.
Thus, today’s final rule addresses the
considerations of ensuring adequate
crash protection, creating an objective
standard, and enabling industry designs
that utilize anchorages to redirect crash
forces by establishing regulatory text
which requires that the electric energy
storage/conversion devices remain
attached to the vehicle by at least one
component anchorage, bracket, or any
structure that transfer loads from the
component to the vehicle structure.
Using this regulatory text, the agency
can afford the manufacturers the
maximum amount of flexibility to
utilize the anchorages as a method for
redirecting crash forces in their vehicle
designs while still ensuring that electric
energy storage/conversion devices do
not become projectiles which can
potentially injure vehicle occupants.
Further, the additional regulatory text
adds clarity and objectivity to the
standard by specifying how the agency
will distinguish between devices that
have remained attached versus those
that have not. Namely, the additional
text clarifies that this standard only
requires that the electric energy storage/
conversion devices maintain a
connection to the vehicle structure at
one or more load transferring point after
it is tested in accordance with the test
procedures in S6.
However, since we are not requiring
all component anchorages to remain
attached to the vehicle at all attachment
locations, we believe that the June 14,
2010 final rule’s conclusion that there is
no need to treat devices inside the
occupant compartment differently from
those outside the occupant
compartment is no longer accurate.
While we agree with petitioners that the
intent of the retention requirement, as
specified in the 2000 final rule, was to
ensure that battery modules would not
become unattached and become flying
projectiles in a crash or subsequent
rollover, this is not the only purpose of
the retention requirement. One of the
purposes of FMVSS No. 305 is to reduce
deaths and injuries during and after a
crash that occur from the intrusion of
electric energy storage/conversion
devices into the occupant compartment.
E:\FR\FM\29JYR1.SGM
29JYR1
jlentini on DSK4TPTVN1PROD with RULES
45442
Federal Register / Vol. 76, No. 146 / Friday, July 29, 2011 / Rules and Regulations
In the June 14, 2010 final rule, the S5.2
requirement that all component
anchorages remain attached to the
vehicle structure at all attachment
locations ensured that the energy
storage/conversion system would not
significantly intrude into the occupant
compartment.
We recognize that, with the new
regulatory text for S5.2 in today’s final
rule, there may be an increased
potential for electric energy storage/
conversion devices to partially detach
from the vehicle structure and intrude
into the occupant compartment. To
address this, we are reintroducing the
requirement that any electric energy
storage/conversion device located
outside the occupant compartment not
intrude into the occupant compartment.
However, we decline to use the term
‘‘passenger compartment airspace’’ as
suggested by the Alliance. A similar
term ‘‘occupant compartment air space’’
was defined by the agency in an
interpretation letter 9 of FMVSS No. 302,
‘‘Flammability of interior materials.’’
Since FMVSS No. 305 addresses safety
from electrolyte spillage, electric shock,
and intrusion of the energy storage
system, and does not address fire safety,
the presence of airspace is not relevant
and we believe that ‘‘occupant
compartment’’ is the more appropriate
term for paragraph S5.2.
We also agree with Honda and the
AIAM that the language of the June 14,
2010 final rule could be interpreted as
unintentionally requiring low mass
components, such as ducts and vents, to
remain attached to the electric energy
storage/conversion systems. As
previously discussed, today’s final rule
adds a new definition for ‘‘electric
energy storage/conversion device,’’
which includes a high voltage battery or
battery pack, capacitor modules, fuel
cell stacks, and rechargeable energy
storage devices used for vehicle
propulsion, but does not include low
mass components, such as ducts, vents,
and wiring harnesses. As the retention
requirements of the final rule are
amended in today’s final rule to apply
to the electric energy storage/conversion
device rather than to the system, these
changes address the concerns raised by
the AIAM and Honda by ensuring that
the retention requirements do not apply
to low mass components.
In conclusion, the regulatory text in
paragraph S5.2 has been amended to
read as follows:
9 Interpretation to Mazda (North America) Inc.—
H. Nayaka: February 15, 1983. An ‘‘occupant
compartment air space’’ is defined as ‘‘the space
within the occupant compartment that normally
contains refreshable air.’’
VerDate Mar<15>2010
16:04 Jul 28, 2011
Jkt 223001
S5.2 Electric energy storage/conversion
device retention. During and after each test
specified in S6 of this standard:
(a) electric energy storage/conversion
devices shall remain attached to the vehicle
by at least one component anchorage,
bracket, or any structure that transfers loads
from the device to the vehicle structure, and
(b) electric energy storage/conversion
devices located outside the occupant
compartment shall not enter the occupant
compartment.
d. Electrical Safety
1. Clarifying the Requirements in
Paragraph S5.3
Paragraph S5.3 of the June 14, 2010
final rule requires that each high voltage
source in a vehicle must meet the
electrical isolation requirements of
subparagraph (a) or the voltage level
requirements of subparagraph (b) after
each test. The subsections state:
(a) The electric isolation between each high
voltage source and the vehicle chassis
electricity-conducting structure must meet
one of the following:
(1) Electrical isolation must be greater than
or equal to 500 ohms/volt for all DC high
voltage sources without continuous
monitoring of electrical isolation during
vehicle operation and for all AC high voltage
sources; or
(2) Electrical isolation must be greater than
or equal to 100 ohms/volt for all DC high
voltage sources with continuous monitoring
of electrical isolation, in accordance with the
requirements of S5.4, during vehicle
operation.
(b) The voltage of the voltage source must
be less than or equal to 30 VAC for AC
components or 60 VDC for DC components.
The Alliance stated that it believes
that the agency has inadvertently
written the electrical safety
requirements in the final rule in a way
that would permit compliance with
S5.3(a)(2) as the sole basis for
complying with S5.3 in total. It noted
that S5.3 states that the vehicle must
meet the electrical isolation
requirements of subparagraph (a) or the
voltage requirements of subparagraph
(b). It further noted that if subparagraph
(a) is chosen, the language permits
compliance to either subparagraph (1) or
subparagraph (2), and if subparagraph
(2) is chosen, there are no isolation
requirements specified for AC high
voltage sources. The Alliance requested
clarification on whether the agency
intended to require 500 ohms/volt
isolation for AC sources in
subparagraph (a) in both the subsidiary
options of subparagraph (a).
NHTSA’s Response: NHTSA agrees
with the Alliance that the regulatory
text in S5.3(a) could be interpreted to
imply that for a vehicle with continuous
monitoring of electrical isolation, only
the DC high voltage components need to
PO 00000
Frm 00046
Fmt 4700
Sfmt 4700
meet the 100 ohms/volt electrical
isolation and that there are no
requirements for AC high voltage
components. This was clearly not the
intent. We are amending the regulatory
text of S5.3(a) to indicate that the
electrical isolation between a given high
voltage source and any electrical chassis
of the vehicle must be greater or equal
to one of the following: (1) 500 ohms/
volt for an AC high voltage source, or (2)
500 ohms/volt for a DC high voltage
source without electrical isolation
monitoring, or (3) 100 ohms/volt for a
DC high voltage source with electrical
isolation monitoring during vehicle
operation. In order to further clarify
paragraph S5.3, we have included
references to specific portions of the test
procedures that apply to the electrical
safety requirements. In addition, the
term ‘‘vehicle chassis electricity
conducting structure’’ in S5.3 has been
replaced by the term ‘‘electrical chassis’’
to maintain consistency with the
changes discussed earlier in this
document. In conclusion, today’s final
rule amends paragraph S5.3 as follows:
S5.3 Electrical safety. After each test
specified in S6 of this standard, each high
voltage source in a vehicle must meet the
electrical isolation requirements of
subparagraph (a) or the voltage level
requirements of subparagraph (b).
(a) The electrical isolation of the high
voltage source, determined in accordance
with the procedure specified in S7.6, must be
greater or equal to one of the following:
(1) 500 ohms/volt for an AC high voltage
source; or
(2) 500 ohms/volt for a DC high voltage
source without electrical isolation
monitoring during vehicle operation; or
(3) 100 ohms/volt for a DC high voltage
source with electrical isolation monitoring,
in accordance with the requirements of S5.4,
during vehicle operation.
(b) The voltages V1, V2, and Vb of the high
voltage source, measured according to the
procedure specified in S7.7, must be less
than or equal to 30 VAC for AC components
or 60 VDC for DC components.
2. Testing Procedures for S5.3(b) Low
Voltage Option
The Alliance also stated in its petition
that S5.3(b) of the final rule adopted a
low-voltage option for providing
electrical isolation, while S7.7 specifies
the procedure for measuring the voltage.
The Alliance petitioned that, for
purposes of clarity, the language
currently specified in S7.6.1 regarding
voltage measurement locations for the
electrical isolation option be added to
S7.7 for the low-voltage option.
NHTSA’s Response: The agency
agrees with the Alliance that the
procedure to measure the voltage in
S7.6.1 should be added to S7.7 for the
E:\FR\FM\29JYR1.SGM
29JYR1
Federal Register / Vol. 76, No. 146 / Friday, July 29, 2011 / Rules and Regulations
purposes of improving clarity. However,
we believe S7.6.1 needs to be modified
to utilize the new definitions adopted
above and to clarify the measurement
procedure before its contents are added
to S7.7. The test procedures in
paragraph S7.6.1 of the June 14, 2010
final rule states:
jlentini on DSK4TPTVN1PROD with RULES
For a vehicle that utilizes an automatic
disconnect between the high voltage source
and the traction system that is physically
contained within the high voltage electric
energy storage/conversion/power generating
system, the electrical isolation measurement
after the test is made from the traction-system
side of the automatic disconnect to the
vehicle chassis electricity-conducting
structure. For a vehicle that utilizes an
automatic disconnect that is not physically
contained within the high voltage electric
energy storage/conversion/power generating
system, the electrical isolation measurement
after the test is made from both the high
voltage source side and from the tractionsystem side of the automatic disconnect to
the vehicle chassis electricity-conducting
structure.
As previously discussed, today’s final
rule has adopted new definitions for
‘‘electric power train’’ and ‘‘electrical
chassis.’’ Therefore, all instances of the
term ‘‘traction-system’’ in S7.6.1 are
replaced by the term ‘‘electric power
train’’ and all instances of the term
‘‘vehicle chassis electricity-conducting
structure,’’ are replaced by the term
‘‘electrical chassis.’’ This final rule also
amends the definition for ‘‘high voltage
source’’ to include electric components
contained in the electric power train
and those connected to it. For high
voltage sources contained within the
electric power train, the regulatory text
of S7.6.1 and S7.7 have been amended
to indicate that the electrical isolation
measurement is made from the side of
the automatic disconnect that is
connected to ‘‘the rest of the electric
powertrain.’’ In addition, the regulatory
text of the June 14, 2010 final rule
S7.6.1 indicates that the ‘‘automatic
disconnect’’ only applies to high voltage
sources within the vehicle’s energy
storage/conversion/power generating
system. We believe that this regulatory
text may be misconstrued, since the
intent of the agency was that the
specifications for the electrical isolation
measurement locations with respect to
the automatic disconnects in S7.6.1
apply to each high voltage source with
automatic disconnects. Therefore, the
regulatory text of S7.6.1 in today’s final
rule is modified as follows and
incorporated into S7.7 as requested by
the Alliance:
For a high voltage source that has an
automatic disconnect that is physically
contained within itself, the electrical
isolation measurement after the test is made
VerDate Mar<15>2010
16:04 Jul 28, 2011
Jkt 223001
from the side of the automatic disconnect
connected to the electric power train or to the
rest of the electric power train if the high
voltage source is a component contained in
the power train. For a high voltage source
that has an automatic disconnect that is not
physically contained within itself, the
electrical isolation measurement after the test
is made from both the high voltage source
side of the automatic disconnect and from
the side of the automatic disconnect
connected to the electric power train or to the
rest of the electric power train if the high
voltage source is a component contained in
the power train.
However, to ensure consistency and
clarity of terminology, today’s final rule
also revises the first sentence in S7.6.1
to indicate that the electric energy
storage/conversion system (rather than
the high voltage source) is connected to
the vehicle’s propulsion system to
enable the propulsion system to be
energized when the vehicle ignition is
in the ‘‘on’’ position. A similar
clarification is made in S7.2 by
replacing ‘‘high voltage system’’ (which
is not defined in the regulatory text)
with ‘‘electric energy storage/conversion
system’’ and ‘‘propulsion motors’’ with
‘‘propulsion system.’’
e. Electrical Isolation Monitoring
While the NPRM did not propose a
requirement for electrical isolation
monitoring, we acknowledged in the
NPRM that the petitioner for rulemaking
requested that FMVSS No. 305 allow for
DC high voltage sources to meet a 100
ohms/volt electrical isolation
requirement when coupled with
electrical isolation monitoring. In the
final rule, based on our analysis of
comments on the NPRM, we required
that each DC high voltage source meet
500 ohms/volt electrical isolation for
vehicles without continuous electrical
isolation monitoring but allowed DC
high voltage sources to meet 100 ohms/
volt electrical isolation if the vehicle
had continuous monitoring of electrical
isolation during vehicle operation. We
required that the system must monitor
its own readiness and provide a warning
display that must be clearly visible from
the driver’s designated seating position
for loss of isolation when tested
according to the test procedure in S8.
The agency stated its belief that
electrical isolation monitoring is
especially needed for electrical
components whose electrical isolation
may degrade over time such as fuel cell
stacks in fuel cell vehicles where the
coolant may increase in conductivity
during vehicle service and thereby
result in a reduction of electrical
isolation. Since it is anticipated that the
100 ohms/volt electrical isolation
requirement for DC high voltage
PO 00000
Frm 00047
Fmt 4700
Sfmt 4700
45443
components would likely be exercised
for the fuel cell stacks and other such
electrical components whose isolation
may degrade over time, we included the
need for isolation monitoring of these
components in the final rule.
In its petitions for reconsideration,
Honda stated that the level of protection
against electric shock should be judged
by the absolute value of electrical
isolation resistance. Honda argued that
whether or not the vehicle is equipped
with an isolation monitor has no
relation to the possibility of electric
shock resulting from touching the high
voltage bus after a crash. Honda
proposed removing entire sections of
S5.4 and S8 related to isolation
monitoring systems. Honda noted that
the 2009 SAE J2578 10 and the 2009 ISO
6469–3 11 draft standards do not require
electrical isolation monitoring for
electrical components with 100 ohms/
volt electrical isolation and requested
that the electrical isolation monitoring
requirements be removed to resolve the
differences between the FMVSS No. 305
and the SAE/ISO standards.
Honda requested that if NHTSA
decides not to remove the electrical
isolation monitoring requirement, it
instead permit periodic electrical
isolation monitoring systems such as
those that do not monitor the electrical
isolation during start-up of vehicle/
system (until main contactor is
connected). Honda stated that the 2010
draft of ISO 6469–3 and the 2006 draft
of ISO 23273–3 permit both continuous
and periodic electrical isolation
measurements during vehicle operation
and that ‘‘periodic’’ systems would also
detect a failure in isolation and
appropriately warn the driver.
Therefore, Honda proposed FMVSS No.
305 include the words ‘‘or periodic’’
after the word, ‘‘continuous’’ in S5.3,
S5.4 and S8.
Further, Honda stated that the
electrical isolation monitoring system
only monitors the entire system during
normal vehicle operation and is not
capable of independently monitoring
each high voltage source. Therefore,
Honda requested that the agency clarify
that the electrical isolation monitoring
system will not be required to
independently monitor each high
voltage source by deleting the words
‘‘For each continuously monitored DC
10 SAE J2578—Recommended practice for general
fuel cell vehicle safety, SAE J2578–2009–01,
Society of Automotive Engineers, https://
standards.sae.org/j2578_200901/.
11 ISO 6469–3—Electrically propelled road
vehicles—Safety specification—Part 3: Protection of
persons against electric shock, 2009, https://
www.iso.org/iso/catalogue_detail?csnumber=45479.
E:\FR\FM\29JYR1.SGM
29JYR1
jlentini on DSK4TPTVN1PROD with RULES
45444
Federal Register / Vol. 76, No. 146 / Friday, July 29, 2011 / Rules and Regulations
high voltage source,’’ from the
regulatory text in S5.4.
Finally, Honda stated that the test
procedure to determine the operation of
isolation monitoring systems does not
allow flexibility in selecting the resistor
that is inserted between the positive
terminal of the high voltage source and
the vehicle chassis electric conducting
structure. Honda noted that, as
prescribed, S8(4) requires inserting a
resistor with resistance equal to the
calculated result 1/(1/(95 times the
working voltage of the high voltage
source)—1/Ri) and does not allow any
flexibility. Honda petitioned to allow
any higher resistor to be used in the test
procedure to determine if the isolation
monitoring system is operating correctly
arguing that the stringency of the test
would not be compromised since higher
resistance would provide a worse case
condition.
NHTSA’s Response—While we agree
with Honda that isolation monitoring is
intended to identify the possibility of
deteriorated isolation that occurs over
time during the normal service life of
the vehicle and that an isolation
monitor is not intended to guard against
the possibility of electric shock resulting
from touching a high voltage source
after a crash, we do not agree that the
requirement for electrical isolation
monitoring should be deleted from the
standard. The requirement that DC high
voltage sources be monitored during
vehicle operation with an isolation
monitoring system that displays a
warning for loss of electrical isolation is
similar to the air bag readiness indicator
required by FMVSS No. 208, ‘‘Occupant
crash protection.’’ Neither the electrical
isolation warning display nor the air bag
readiness indicator provides protection
during or after a crash. However, these
indicators serve to provide the driver
information that the related system may
not be in proper working condition.
Electrical isolation monitoring
addresses a relevant safety concern
because electric vehicles that use the
100 ohms/volt electrical isolation option
to comply with the electrical safety
requirements may likely be powered by
fuel cells which have coolant that can
deteriorate the electrical isolation over
time. The agency made the decision to
require electrical isolation monitoring
based on careful analysis of the
electrical safety concerns associated
with providing adequate electrical
shock protection both during vehicle
operation and following a crash.
We also note that the electrical
isolation and the electrical isolation
monitoring requirements in the June 14,
2010 final rule were consistent with the
joint Alliance/AIAM comments to the
VerDate Mar<15>2010
16:04 Jul 28, 2011
Jkt 223001
NPRM and SAE J1766. The standards
referred to by Honda in its petition (SAE
J2578 and ISO 6469–3) are draft
documents that may be subject to
change. For example, the 2009 draft of
ISO 6469–3 does not require electrical
isolation monitoring while the 2010
version makes provisions for continuous
and periodic electrical isolation
monitoring. As the aforementioned
voluntary standards are still in flux
regarding requiring electrical isolation
monitoring, and as the agency believes
that electrical isolation monitoring
addresses an important safety concern
by warning the driver of a possible
degradation in electrical isolation, we
are denying Honda’s petition to remove
the electrical isolation monitoring
requirements from S5.4 and S8.
However, we agree with Honda’s
petition that the term ‘‘continuous’’ in
the electrical isolation monitoring
system requirement should be clarified.
Since the standard provides a test
procedure and performance criteria for
assessing the operation of the electrical
isolation monitoring system, we believe
there is no need to specify the type of
monitoring system. The only
requirement contained in today’s final
rule is that the monitoring systems meet
the performance criteria in S5.4 when
tested according to the procedure in S8.
Therefore, rather than adding the
additional term ‘‘or periodic,’’ as
suggested by Honda, we are deleting the
specification for the monitoring system
to be ‘‘continuous’’ in S5.3, S5.4, and S8
to address its concern. We are also
modifying the regulatory text of S5.4
slightly to improve clarity.
We agree with Honda that electrical
isolation monitoring systems may only
monitor the whole vehicle system.
However, the regulatory requirements in
S5.4 only apply to those DC high voltage
sources that manufacturers have chosen
to certify to the 100 ohms/volt electrical
isolation requirement and do not
comply with the 500 ohms/volt
electrical isolation requirement.
Therefore, the test procedure in S8
evaluates the performance of the
monitoring system for each DC high
voltage source that is certified to 100
ohms/volt electrical isolation. The
procedures in S8 are intended to test for
the condition when electrical isolation
of each DC high voltage source (certified
to the 100 ohms/volt requirement) falls
below 100 ohms/volt. Therefore, we do
not grant Honda’s request to remove the
phrase ‘‘For each continuously
monitored DC high voltage source’’ from
the regulatory text in S5.4.
Finally, Honda also petitioned for
flexibility in the use of any higher
resistor in the test procedure to
PO 00000
Frm 00048
Fmt 4700
Sfmt 4700
determine if the isolation monitoring
system is operating correctly. It argued
that allowing a higher resistance would
not compromise the stringency of the
requirements since it would provide for
a worse case condition. In the June 14,
2010 final rule, the resistance of the
external resistor applied in the test
procedure detailed in S8 is calculated
such that the combined electrical
isolation resistance of the high voltage
source and the external resistor results
in electrical isolation of 95 ohms/volt
which is 95 percent of the required
electrical isolation. The electrical
isolation monitor is required to display
a warning when the electrical isolation
falls to 95 ohms/volt. If the resistance of
the external resistor applied in the test
is greater than that specified in S8, as
requested by Honda, then we agree that
the combined electrical isolation for
which the monitoring system will need
to display a warning may be greater than
100 ohms/volt, thereby making the
requirement more stringent.
The final rule requires 100 ohms/volt
electrical isolation for monitored DC
high voltage sources. For compliance
purposes, we are assessing the operation
of the monitoring system when the
electrical isolation falls just below the
required value. The final rule does not
preclude manufacturers from having the
isolation monitor warning display come
on at a higher value than the minimum
electrical isolation of 100 ohms/volt.
Therefore, we do not believe it is
necessary to grant Honda’s request to
change S8(4) to include an external
resistor of higher resistance than that
specified by the calculation.
However, we do see merit in
including some flexibility in the
resistance of the external resistor
selected to evaluate the electrical
isolation monitoring system such that it
is easy for the testing personnel to select
an off-the-shelf resistor instead of
having to build a resistor to meet the
exact computed resistance of the
external resistor. Therefore, we are
specifying that the resistance of the
external resistor be such that the
combined electrical isolation is greater
or equal to 95 ohms/volt but less than
100 ohms/volt. This will allow the
agency to test the operation of the
monitoring system when the electrical
isolation falls just below the required
100 ohms/volt, and will provide
manufacturers additional flexibility in
selecting resistors for testing.
f. Electric Energy Storage Device Stateof-Charge
In the June 14, 2010 final rule, we
required that prior to the crash test, the
electric energy storage device be at the
E:\FR\FM\29JYR1.SGM
29JYR1
Federal Register / Vol. 76, No. 146 / Friday, July 29, 2011 / Rules and Regulations
jlentini on DSK4TPTVN1PROD with RULES
maximum state-of-charge recommended
by the manufacturer, as stated in the
vehicle owner’s manual or on a label
that is permanently affixed to the
vehicle; or if the manufacturer has made
no recommendation in the owner’s
manual or on a label permanently
affixed to the vehicle, at a state-ofcharge of not less than 95 percent of the
maximum capacity of the electric energy
storage device; or if the electric energy
storage device(s) is/are rechargeable
only by an energy source on the vehicle,
at any state-of-charge within the normal
operating voltage defined by the vehicle
manufacturer. These state-of-charge
provisions in the June 14, 2010 final
rule were substantively identical to the
original FMVSS No. 305 that existed
before the NPRM in this rulemaking.
In its petition asking the agency to
reconsider these provisions, the
Alliance requested that FMVSS No. 305
be amended to allow testing at ‘‘any
state-of-charge which allows the normal
operation of the power train as
recommended by the manufacturer.’’ In
support of this request, the Alliance
stated that the United Nations Economic
Commission for Europe (UNECE) draft
regulations (ECE R.94 and 95) 12 already
propose to permit testing of electric
vehicles at any state-of-charge. The
Alliance stated that this proposed
change would (1) allow for systems with
external charging capability to be tested
at lower state-of-charge (similar to
hybrid electric vehicles), (2) result in
reduced facility/test personnel risk
(similar to the current use of stoddard
in fuel systems), and (3) further provide
an opportunity for harmonization with
UNECE regulations. Thus, the Alliance
argued that in the interest of safety in
the testing environment and
harmonization, the UNECE allowance
on state-of-charge should be adopted.
Ford also offered comments regarding
the state-of-charge and the FMVSS No.
305 test conditions. Ford stated that
state-of-charge does not affect the energy
storage/conversion system mass,
electrolyte volume or containment
capability and does not affect electrical
isolation. Ford presented theoretical
examples of systems suffering loss of
electrical isolation during the crash test
prescribed in the standard. Using the
electrical isolation test procedure
outlined in the standard, Ford
demonstrated that the loss in electrical
12 ECE R.94—Uniform Provisions Concerning the
Approval of Vehicles with Regard to the Protection
of the Occupants in the Event of a Frontal Collision,
draft modifications of September 2010. ECE R.95—
Uniform Provisions Concerning the Approval of
Vehicles with Regard to the Protection of the
Occupants in the Event of a Lateral Collision, draft
modifications of September 2010.
VerDate Mar<15>2010
16:04 Jul 28, 2011
Jkt 223001
isolation was detected when the system
was energized at 95 percent and 5
percent of the maximum state-of-charge.
Ford agreed with the Alliance that the
lower state-of-charge would reduce
potential risk to test personnel similar to
the use of substitute liquids and gases
in other FMVSSs.
In addition, Honda’s petition stated
that the state-of-charge testing
requirements should be amended to
address new technologies such as plug
in hybrid electric vehicles (PHEVs)
which will become common in the near
future. Honda noted that the regulatory
text indicates that if the manufacturer of
vehicles (such as PHEVs) recommends a
specific maximum state-of-charge, the
test would be conducted at the specified
maximum state-of-charge. However, if
the manufacturer has no
recommendation, the test would be
conducted at a state-of-charge of not less
than 95 percent of the maximum
capacity of the electric energy storage
device.
Honda argued that the state-of-charge
for an electric energy storage device can
vary due to environmental conditions
such as temperature or service life and
that it will not be recommending a
specific state-of-charge in the owner’s
manual or on the label affixed to the
vehicle because the electric energy
storage device is charged appropriately
by an off-board and/or on-board charger
recommended by the manufacturer.
Thus, Honda petitioned to have the
regulatory text of S7.1 changed from
‘‘recommended by the manufacturer, as
stated in the vehicle owner’s manual or
on a label that is permanently affixed to
the vehicle’’ to ‘‘in accordance with the
vehicle manufacturer’s recommended
charging procedures.’’ For those
manufacturers that make no
recommendation, Honda further
petitioned to have the regulatory text of
S7.1(b) changed from ‘‘made no
recommendation in the owner’s manual
or on a label permanently affixed to the
vehicle’’ to ‘‘made no recommendation
for charging procedures.’’
NHTSA’s Response: NHTSA does not
agree with the Alliance and Ford that
the electric energy storage device should
be at any state-of-charge that allows for
the normal operation of the power train
as recommended by the manufacturer.
Specifying the state-of-charge provides a
uniform way of testing and ensures all
electric powered motor vehicles are
tested in a similar manner.
We agree with Ford that the electrical
isolation resistance measurement
remains unchanged for different
operating voltages and that loss in
electrical isolation can be detected by
the method outlined in the standard for
PO 00000
Frm 00049
Fmt 4700
Sfmt 4700
45445
different states of charge. However, we
are concerned that certain electric
components, such as capacitor networks
within the electric power train may not
be tested to their design limits when
tested at a lower state-of-charge. When
the vehicle crash test is conducted at the
maximum state-of-charge, there is
potential for some of the capacitor
voltages to reach their design limits
which may result in an electric short
and hence cause a loss in electrical
isolation. This potential safety hazard
may not occur when the vehicle is
tested at a lower state-of-charge which
results in a lower energy test condition.
We also do not agree with petitioners
that testing at lower state-of-charge to
evaluate electrical safety is similar to
fuel system integrity testing with
stoddard fluid in gasoline powered
vehicles and nitrogen in compressed
natural gas vehicles. While use of
stoddard fluids and nitrogen do not
change the performance of the fuel
containers during and after the test,
using lower state-of-charge may not
evaluate certain electrical components
at their design limits.
We further note that the December
2010 draft of SAE J2929—‘‘Electric and
Hybrid Vehicle Propulsion Battery
System Safety Standard for LithiumBased Rechargeable Cells,’’ requires the
battery state-of-charge to be at the
maximum possible during normal
vehicle operation before the battery
system is tested for mechanical shock
hazard in a vehicle pursuant to FMVSS
No. 305. While the draft SAE J2929 test
applies to different safety concerns, it
does involve the same crash tests as this
standard and utilizes similar state-ofcharge requirements. Therefore, the
agency’s position on the state-of-charge
of the energy storage/conversion system
prior to the crash test is consistent with
the future voluntary industry standard
for battery systems. We are therefore
denying the petition from the Alliance
and Ford to conduct the crash test at
any state-of-charge which allows the
normal operation of the power train as
recommended by the manufacturer.
However, we agree with Honda that
the maximum state-of-charge may vary
based on environmental conditions such
as the age of the battery, temperature
and service life for today’s battery
technologies. Thus, having the label
specify the maximum state-of-charge in
the owner’s manual or a label
permanently affixed to the vehicle may
not provide consumers the information
they need to recharge their vehicle
throughout the vehicle’s life. However,
manufacturers will likely provide
information to consumers on the proper
charging procedures to achieve
E:\FR\FM\29JYR1.SGM
29JYR1
45446
Federal Register / Vol. 76, No. 146 / Friday, July 29, 2011 / Rules and Regulations
jlentini on DSK4TPTVN1PROD with RULES
maximum range, as suggested by Honda.
Therefore, we are modifying the
regulatory text to indicate that the
maximum state-of-charge in accordance
with the vehicle manufacturer’s
recommended charging procedure, as
stated in the vehicle owner’s manual or
on a label that is permanently affixed to
the vehicle, will be used. In the case
where no such recommendation is
provided in the owner’s manual or on
a label permanently affixed to the
vehicle, the test will be conducted with
the electric energy storage/conversion
device charged to 95 percent of its rated
capacity.
g. Physical Barrier Compliance Option
for Electrical Safety
The June 14, 2010 final rule did not
include a physical barrier compliance
option for electrical safety since it was
beyond the scope of the rulemaking. In
addition, the agency stated in the final
rule that it was uncertain whether
indirect contact failure modes would be
sufficiently accounted for by the
protective barrier compliance option
and noted that it had initiated a research
program to better understand the issues.
In its petition for reconsideration, the
Alliance disagreed with the agency’s
concern that the physical barrier option
may not appropriately address electrical
shock from indirect contact. The
Alliance stated its belief that the test
procedure for the protective barrier
compliance option is equally valid for
assessing both direct and indirect
contact. It stated that the basic premise
of the protective barrier compliance
option is that if a person cannot contact
high voltage sources, then there is little
chance of injury from such sources.
The Alliance further stated that there
is worldwide recognition and
acceptance of the barrier option as a
means for providing electrical safety,
and updating FMVSS No. 305, as
requested, would be a key enabler
facilitating the introduction of all forms
of electric-powered vehicles into the
U.S. mainstream vehicle fleet. It argued
that such vehicle technologies are vital
to achieving the current
Administration’s energy and emissions
goals. The Alliance further stated that
given the urgent need for the barrier
option and the fact that the barrier
option in the draft GTR language (the
ELSA document) is fully accepted by
the international community, it is not
necessary to delay a rulemaking
proposal. Accordingly, the Alliance
requested that NHTSA initiate a new
rulemaking to incorporate the barrier
option into FMVSS No. 305, and to
complete this rulemaking with an
urgency that is consistent with the
VerDate Mar<15>2010
16:04 Jul 28, 2011
Jkt 223001
national priorities to improve energy
independence and reduced emissions.
NHTSA’s Response: Our position on
the requested physical barrier option
has not substantively changed since the
June 14, 2010 final rule. As noted in the
June 14, 2010 final rule, NHTSA is
doing research to evaluate the suitability
of including the protective barrier
option in FMVSS No. 305. NHTSA is
aware that other countries have adopted
a similar option in their regulations for
electrical safety, but that does not
eliminate the need for the agency to
obtain the necessary supporting
research to fully understand the
consequences of adding this option as a
means for providing electrical safety in
FMVSS No. 305. Prior to changing any
safety standard, NHTSA must first
ensure that the proposed requirement
provides an adequate level of safety and
does not create an inadvertent safety
risk to the motoring public, or first
responders responding to the scene of a
crash. Upon completion of the agency’s
research, NHTSA will make a decision
whether to include physical barriers as
an option for providing electrical safety
in FMVSS No. 305. If the agency
decides that a proposal for the
protective barrier compliance option has
merit, it will propose performance
requirements, as well as a test
procedure, at that time.
h. Use of Alternative Gas for Testing
Hydrogen Fuel Cell Vehicles
The June 14, 2010 final rule also did
not include a provision for testing
hydrogen fuel cell vehicles using an
inert gas, such as helium. When testing
with an inert gas, the fuel cell stacks are
not energized and consequently will not
generate any electrical energy from
which to measure electrical output. The
final rule stated that the agency was
researching potential crash test
procedures for testing fuel cell vehicles,
but would not address this issue as part
of the June 14, 2010 final rule.
Petitions for reconsideration from the
AIAM and Honda requested the agency
to expedite this research so that a
decision can be made in the near future
for testing hydrogen fuel cell vehicles
with helium-filled fuel containers. The
organizations noted that fuel cell
vehicles will be required to comply with
FMVSS No. 305 by September 1, 2011.
They argued that testing for those
vehicles will then have to be conducted
using hydrogen gas in accordance with
the current regulation, if no changes are
made. The AIAM and Honda further
stated that other FMVSS crash test
procedures (i.e. FMVSS Nos. 208,
‘‘Occupant crash protection,’’ 214, ‘‘Side
impact crash protection,’’ 301, ‘‘Fuel
PO 00000
Frm 00050
Fmt 4700
Sfmt 4700
system integrity,’’ and 303, ‘‘Fuel
system integrity of compressed natural
gas vehicles’’) require filling the fuel
tank with alternative fuel to ensure
safety during and after the crash test and
the use of gasoline, diesel, and
compressed natural gas in such tests is
prohibited. The organizations requested
that the test procedure for FMVSS No.
305 be aligned with the procedures of
other existing crash-related regulations.
Both organizations further reiterated
their original comments to the NPRM
that current Japanese regulations require
the use of helium gas in crash tests, and
prohibit the use of hydrogen.
NHTSA’s Response—As noted in the
June 14, 2010 final rule, the agency has
ongoing research in developing a test
procedure for evaluating the electrical
safety of fuel cell vehicles with an inert
gas and inactive fuel cells and the
agency’s position has not substantively
changed since then. When an inert gas
is used instead of hydrogen in fuel cell
vehicles, some of the electrical
components of the electric power train
may be rendered inactive. Currently, the
agency has not developed a test
procedure to test the electrical safety of
all high voltage sources accurately when
an inert gas is used during testing of fuel
cell vehicles. We note that while the
Japanese regulation and the ELSA
document permit the use of helium gas
in crash tests of hydrogen powered
vehicles, both the Japanese regulation
and the ELSA document do not specify
a test procedure to evaluate the
electrical safety of such vehicles when
an inert gas is used in place of
hydrogen.
Therefore, the agency believes further
work is needed to resolve the identified
issues in testing hydrogen fuel cell
vehicles. While there are currently no
explicit provisions for using an
alternative gas in lieu of hydrogen,
comparable to the fuel system integrity
standards for gasoline or compressed
natural gas powered vehicles, the test
procedures in an FMVSS are those that
the agency will use to determine
compliance to the particular standard.
Manufacturers are not prohibited from
using other test procedures for
compliance certification and may elect
to conduct crash tests of hydrogen fuel
cell vehicles with a less volatile gas
such as helium.
i. Low-Energy Compliance Option for
Electrical Safety
Although the NPRM sought comment
on whether or not the requested lowenergy compliance option for electrical
safety should be included, it did not
include this option in the proposed rule.
After carefully considering the
E:\FR\FM\29JYR1.SGM
29JYR1
Federal Register / Vol. 76, No. 146 / Friday, July 29, 2011 / Rules and Regulations
comments received, the agency did not
include the low-energy compliance
option in the June 14, 2010 final rule as
we remained unconvinced that the
option was necessary and that it would
adequately address the safety concerns
of FMVSS No. 305. In its petition for
reconsideration, the Alliance stated its
continued belief that the low-energy
option has merit and should be
included in FMVSS No. 305. However,
the Alliance also recognized that more
research may be required in order to
fully understand the safety implications
of this option. Given the available
information on the low-energy
compliance option for electrical safety
has not significantly changed, NHTSA’s
position on the low-energy compliance
option remains as expressed in the June
14, 2010 final rule.
V. Rulemaking Analyses and Notices
jlentini on DSK4TPTVN1PROD with RULES
a. Executive Order 12866, Executive
Order 13563, and DOT Regulatory
Policies and Procedures
NHTSA has considered the impact of
this rulemaking action under Executive
Order 12866, Executive Order 13563,
and the Department of Transportation’s
regulatory policies and procedures. This
rulemaking document was not reviewed
by the Office of Management and
Budget under E.O. 12866, ‘‘Regulatory
Planning and Review.’’ It is not
considered to be significant under E.O.
12866 or the Department’s Regulatory
Policies and Procedures (44 FR 11034;
February 26, 1979). NHTSA has
determined that the effects of this final
rule are minor and that a regulatory
evaluation is not needed to support the
subject rulemaking. Today’s final rule
only makes slight changes to the
regulatory text of the June 14, 2010 final
rule to add clarification and does not
impose significant costs beyond those
already required by the June 14, 2010
final rule.
b. Regulatory Flexibility Act
Pursuant to the Regulatory Flexibility
Act (5 U.S.C. 601 et seq., as amended by
the Small Business Regulatory
Enforcement Fairness Act (SBREFA) of
1996), whenever an agency is required
to publish a notice of proposed
rulemaking or final rule, it must prepare
and make available for public comment
a regulatory flexibility analysis that
describes the effect of the rule on small
entities (i.e., small businesses, small
organizations, and small governmental
jurisdictions). No regulatory flexibility
analysis is required if the head of an
agency certifies the rule will not have a
significant economic impact on a
substantial number of small entities.
VerDate Mar<15>2010
16:04 Jul 28, 2011
Jkt 223001
SBREFA amended the Regulatory
Flexibility Act to require Federal
agencies to provide a statement of the
factual basis for certifying that a rule
will not have a significant economic
impact on a substantial number of small
entities.
NHTSA has considered the effects of
this final rule under the Regulatory
Flexibility Act. I certify that this final
rule does not have a significant
economic impact on a substantial
number of small entities. Any small
manufacturers that might be affected by
this final rule are already subject to the
requirements of FMVSS No. 305.
Further, the agency believes the testing
associated with the requirements added
by this final rule are not substantial and
to some extent are already being
voluntarily borne by the manufacturers
pursuant to SAE J1766, SAE J2578, ECE
regulations, and other voluntary
industry standards. Therefore, the
impacts on any small businesses
affected by this rulemaking would not
be substantial.
45447
When a motor vehicle safety standard is in
effect under this chapter, a State or a political
subdivision of a State may prescribe or
continue in effect a standard applicable to
the same aspect of performance of a motor
vehicle or motor vehicle equipment only if
the standard is identical to the standard
prescribed under this chapter.
administrative law 13 addressing the
same aspect of performance, not today’s
rulemaking.
The express preemption provision
described above is subject to a savings
clause under which ‘‘[c]ompliance with
a motor vehicle safety standard
prescribed under this chapter does not
exempt a person from liability at
common law.’’ 49 U.S.C. 30103(e).
Pursuant to this provision, State
common law tort causes of action
against motor vehicle manufacturers
that might otherwise be preempted by
the express preemption provision are
generally preserved. However, the
Supreme Court has recognized the
possibility, in some instances, of
implied preemption of State common
law tort causes of action by virtue of
NHTSA’s rules—even if not expressly
preempted.
This second way that NHTSA rules
can preempt is dependent upon the
existence of an actual conflict between
an FMVSS and the higher standard that
would effectively be imposed on motor
vehicle manufacturers if someone
obtained a State common law tort
judgment against the manufacturer—
notwithstanding the manufacturer’s
compliance with the NHTSA standard.
Because most NHTSA standards
established by an FMVSS are minimum
standards, a State common law tort
cause of action that seeks to impose a
higher standard on motor vehicle
manufacturers will generally not be
preempted. However, if and when such
a conflict does exist—for example, when
the standard at issue is both a minimum
and a maximum standard—the State
common law tort cause of action is
impliedly preempted. See Geier v.
American Honda Motor Co., 529 U.S.
861 (2000).
Pursuant to Executive Order 13132,
NHTSA has considered whether this
rule could or should preempt State
common law causes of action. The
agency’s ability to announce its
conclusion regarding the preemptive
effect of one of its rules reduces the
likelihood that preemption will be an
issue in any subsequent tort litigation.
To this end, the agency has examined
the nature (e.g., the language and
structure of the regulatory text) and
objectives of today’s rule and finds that
this rule merely clarifies the
requirements and definitions contained
in the June 14, 2010 final rule. As such,
NHTSA does not intend that this rule
preempt state tort law that would
effectively impose a higher standard on
49 U.S.C. 30103(b)(1). It is this statutory
command that preempts any nonidentical State legislative and
13 The issue of potential preemption of state tort
law is addressed in the immediately following
paragraph discussing implied preemption.
c. Executive Order 13132 (Federalism)
NHTSA has examined today’s final
rule pursuant to Executive Order 13132
(64 FR 43255; Aug. 10, 1999) and
concluded that no additional
consultation with States, local
governments, or their representatives is
mandated beyond the rulemaking
process. The agency has concluded that
the final rule does not have sufficient
federalism implications to warrant
consultation with State and local
officials or the preparation of a
federalism summary impact statement.
The final rule does not have
‘‘substantial direct effects 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.’’ Today’s final
rule does not impose substantial
additional requirements. Instead, it
clarifies the existing requirements from
the June 14, 2010 final rule.
NHTSA rules can have preemptive
effect in two ways. First, the National
Traffic and Motor Vehicle Safety Act
contains an express preemption
provision:
PO 00000
Frm 00051
Fmt 4700
Sfmt 4700
E:\FR\FM\29JYR1.SGM
29JYR1
45448
Federal Register / Vol. 76, No. 146 / Friday, July 29, 2011 / Rules and Regulations
motor vehicle manufacturers than that
established by today’s rule.
Additionally, in the June 14, 2010 final
rule, the agency did not assert
preemption. Establishment of a higher
standard by means of State tort law
would not conflict with the exemption
announced here. Without any conflict,
there could not be any implied
preemption of a State common law tort
cause of action.
d. National Environmental Policy Act
NHTSA has analyzed this rulemaking
action for the purposes of the National
Environmental Policy Act. The agency
has determined that implementation of
this action will not have any significant
impact on the quality of the human
environment.
e. Executive Order 12988 (Civil Justice
Reform)
When promulgating a regulation,
agencies are required under Executive
Order 12988 to make every reasonable
effort to ensure that the regulation, as
appropriate: (1) Specifies in clear
language the preemptive effect; (2)
specifies in clear language the effect on
existing Federal law or regulation,
including all provisions repealed,
circumscribed, displaced, impaired, or
modified; (3) provides a clear legal
standard for affected conduct rather
than a general standard, while
promoting simplification and burden
reduction; (4) specifies in clear language
the retroactive effect; (5) specifies
whether administrative proceedings are
to be required before parties may file
suit in court; (6) explicitly or implicitly
defines key terms; and (7) addresses
other important issues affecting clarity
and general draftsmanship of
regulations.
Pursuant to this Order, NHTSA notes
as follows. The preemptive effect of
today’s final rule is discussed above.
NHTSA notes further that there is no
requirement that individuals submit a
petition for reconsideration or pursue
other administrative proceeding before
they may file suit in court.
jlentini on DSK4TPTVN1PROD with RULES
f. Privacy Act
Please note that anyone is able to
search the electronic form of all
comments received into any of our
dockets by the name of the individual
submitting the comment (or signing the
comment, if submitted on behalf of an
association, business, labor union, etc.).
You may review DOT’s complete
Privacy Act Statement in the Federal
Register published on April 11, 2000
(65 FR 19477–78), or online at https://
www.dot.gov/privacy.html.
VerDate Mar<15>2010
16:04 Jul 28, 2011
Jkt 223001
g. Paperwork Reduction Act
Under the Paperwork Reduction Act
of 1995 (PRA), a person is not required
to respond to a collection of information
by a Federal agency unless the
collection displays a valid OMB control
number. There are no information
collection requirements associated with
this final rule.
h. National Technology Transfer and
Advancement Act
Under the National Technology
Transfer and Advancement Act of 1995
(NTTAA) (Pub. L. 104–113), ‘‘all Federal
agencies and departments shall use
technical standards that are developed
or adopted by voluntary consensus
standards bodies, using such technical
standards as a means to carry out policy
objectives or activities determined by
the agencies and departments.’’
Voluntary consensus standards are
technical standards (e.g., materials
specifications, test methods, sampling
procedures, and business practices) that
are developed or adopted by voluntary
consensus standards bodies, such as the
Society of Automotive Engineers (SAE).
The NTTAA directs us to provide
Congress, through OMB, explanations
when we decide not to use available and
applicable voluntary consensus
standards. FMVSS No. 305 has
historically drawn largely from SAE
J1766. Prior to this update, FMVSS No.
305 was based on the April 2005 version
of SAE J1766. However, today’s final
rule has made certain amendments to
the standard to reflect the development
of new voluntary consensus standards
that have superseded SAE J1766. Thus,
today’s final rule makes revisions to the
June 14, 2010 final rule that updated
FMVSS No. 305.
i. Unfunded Mandates Reform Act
The Unfunded Mandates Reform Act
of 1995 requires agencies to prepare a
written assessment of the costs, benefits
and other effects of proposed or final
rules that include a Federal mandate
likely to result in the expenditure by
State, local or Tribal governments, in
the aggregate, or by the private sector, of
more than $100 million annually
(adjusted for inflation with base year of
1995). Today’s final rule, which clarifies
the June 14, 2010 final rule, will not
result in expenditures by State, local or
Tribal governments, in the aggregate, or
by the private sector in excess of $100
million annually.
j. Plain Language
Executive Order 12866 requires each
agency to write all rules in plain
language. Application of the principles
PO 00000
Frm 00052
Fmt 4700
Sfmt 4700
of plain language includes consideration
of the following questions:
• Have we organized the material to
suit the public’s needs?
• Are the requirements in the rule
clearly stated?
• Does the rule contain technical
language or jargon that isn’t clear?
• Would a different format (grouping
and order of sections, use of headings,
paragraphing) make the rule easier to
understand?
• Would more (but shorter) sections
be better?
• Could we improve clarity by adding
tables, lists, or diagrams?
• What else could we do to make the
rule easier to understand?
If you have any responses to these
questions, please notify the agency in
writing.
k. Regulation Identifier Number (RIN)
The Department of Transportation
assigns a regulation identifier number
(RIN) to each regulatory action listed in
the Unified Agenda of Federal
Regulations. The Regulatory Information
Service Center publishes the Unified
Agenda in April and October of each
year. You may use the RIN contained in
the heading at the beginning of this
document to find this action in the
Unified Agenda.
VI. Regulatory Text
List of Subjects in 49 CFR part 571
Imports, Motor vehicles, Motor
vehicle safety.
In consideration of the foregoing,
NHTSA amends 49 CFR part 571 as
follows:
PART 571—FEDERAL MOTOR
VEHICLE SAFETY STANDARDS
1. The authority citation for part 571
continues to read as follows:
■
Authority: 49 U.S.C. 322, 30111, 30115,
30117, and 30166; delegation of authority at
49 CFR 1.50.
2. Amend § 571.305 by revising S1,
S2, S3, S4, S5.2, S5.3, S5.4, S7.1, S7.2,
S7.6.1, S7.6.4, S7.6.5, S7.6.6, S7.6.7,
S7.7, and S8 and Figures 1 through 5 as
follows:
■
§ 571.305 Standard No. 305; Electricpowered vehicles: Electrolyte spillage and
electrical shock protection.
S1. Scope. This standard specifies
requirements for limitation of
electrolyte spillage, retention of electric
energy storage/conversion devices, and
protection from harmful electric shock
during and after a crash.
S2. Purpose. The purpose of this
standard is to reduce deaths and injuries
E:\FR\FM\29JYR1.SGM
29JYR1
jlentini on DSK4TPTVN1PROD with RULES
Federal Register / Vol. 76, No. 146 / Friday, July 29, 2011 / Rules and Regulations
during and after a crash that occurs
because of electrolyte spillage from
electric energy storage devices,
intrusion of electric energy storage/
conversion devices into the occupant
compartment, and electrical shock.
S3. Application. This standard
applies to passenger cars, and to
multipurpose passenger vehicles, trucks
and buses with a GVWR of 4,536 kg or
less, that use electrical propulsion
components with working voltages more
than 60 volts direct current (VDC) or 30
volts alternating current (VAC), and
whose speed attainable over a distance
of 1.6 km on a paved level surface is
more than 40 km/h.
S4. Definitions.
Automatic disconnect means a device
that when triggered, conductively
separates a high voltage source from the
electric power train or the rest of the
electric power train.
Electric energy storage device means a
high voltage source that stores energy
for vehicle propulsion. This includes,
but is not limited to, a high voltage
battery or battery pack, rechargeable
energy storage device, and capacitor
module.
Electric energy storage/conversion
device means a high voltage source that
stores or converts energy for vehicle
propulsion. This includes, but is not
limited to, a high voltage battery or
battery pack, fuel cell stack,
rechargeable energy storage device, and
capacitor module.
Electric energy storage/conversion
system means an assembly of electrical
components that stores or converts
electrical energy for vehicle propulsion.
This includes, but is not limited to, high
voltage batteries or battery packs, fuel
cell stacks, rechargeable energy storage
systems, capacitor modules, inverters,
interconnects, and venting systems.
Electric power train means an
assembly of electrically connected
components which includes, but is not
limited to, electric energy storage/
conversion systems and propulsion
systems.
Electrical chassis means conductive
parts of the vehicle whose electrical
potential is taken as reference and
which are: (1) conductively linked
together, and (2) not high voltage
sources during normal vehicle
operation.
Electrical isolation of a high voltage
source in the vehicle means the
electrical resistance between the high
voltage source and any of the vehicle’s
electrical chassis divided by the
working voltage of the high voltage
source.
High voltage source means any
electric component contained in the
VerDate Mar<15>2010
16:04 Jul 28, 2011
Jkt 223001
electric power train or conductively
connected to the electric power train
that has a working voltage greater than
30 VAC or 60 VDC.
Propulsion system means an assembly
of electric or electro-mechanical
components or circuits that propel the
vehicle using the energy that is supplied
by a high voltage source. This includes,
but is not limited to, electric motors,
inverters/converters, electronic
controllers, and associated wire
harnesses and connectors, and coupling
systems for charging rechargeable
energy storage systems.
*
*
*
*
*
S5.2 Electric energy storage/
conversion device retention. During and
after each test specified in S6 of this
standard:
(a) Electric energy storage/conversion
devices shall remain attached to the
vehicle by at least one component
anchorage, bracket, or any structure that
transfers loads from the device to the
vehicle structure, and
(b) Electric energy storage/conversion
devices located outside the occupant
compartment shall not enter the
occupant compartment.
S5.3 Electrical safety. After each test
specified in S6 of this standard, each
high voltage source in a vehicle must
meet the electrical isolation
requirements of subparagraph (a) or the
voltage level requirements of
subparagraph (b).
(a) The electrical isolation of the high
voltage source, determined in
accordance with the procedure specified
in S7.6, must be greater than or equal to
one of the following:
(1) 500 ohms/volt for an AC high
voltage source; or
(2) 500 ohms/volt for a DC high
voltage source without electrical
isolation monitoring during vehicle
operation; or
(3) 100 ohms/volt for a DC high
voltage source with electrical isolation
monitoring, in accordance with the
requirements of S5.4, during vehicle
operation.
(b) The voltages V1, V2, and Vb of the
high voltage source, measured according
to the procedure specified in S7.7, must
be less than or equal to 30 VAC for AC
components or 60 VDC for DC
components.
S5.4 Electrical isolation monitoring.
Each DC high voltage source with
electrical isolation monitoring during
vehicle operation pursuant to S5.3(a)(2)
shall be monitored by an electrical
isolation monitoring system that
displays a warning for loss of isolation
when tested according to S8. The
system must monitor its own readiness
PO 00000
Frm 00053
Fmt 4700
Sfmt 4700
45449
and the warning display must be visible
to the driver seated in the driver’s
designated seating position.
*
*
*
*
*
S7.1 Electric energy storage device
state-of-charge. The electric energy
storage device shall be at the state-ofcharge specified in either subparagraph
(a), (b), or (c):
(a) At the maximum state-of-charge in
accordance with the vehicle
manufacturer’s recommended charging
procedures, as stated in the vehicle
owner’s manual or on a label that is
permanently affixed to the vehicle; or
(b) If the manufacturer has made no
recommendation for charging
procedures in the owner’s manual or on
a label permanently affixed to the
vehicle, at a state-of-charge of not less
than 95 percent of the maximum
capacity of the electric energy storage
device; or
(c) If the electric energy storage
device(s) is/are rechargeable only by an
energy source on the vehicle, at any
state-of-charge within the normal
operating voltage defined by the vehicle
manufacturer.
S7.2 Vehicle conditions. The switch
or device that provides power from the
electric energy storage/conversion
system to the propulsion system is in
the activated position or the ready-todrive position.
*
*
*
*
*
S7.6.1 Prior to any barrier impact
test, the energy storage/conversion
system is connected to the vehicle’s
propulsion system, and the vehicle
ignition is in the ‘‘on’’ (propulsion
system energized) position. Bypass any
devices or systems that do not allow the
propulsion system to be energized at the
time of impact when the vehicle
ignition is on and the vehicle is in
neutral. For a high voltage source that
has an automatic disconnect that is
physically contained within itself, the
electrical isolation measurement after
the test is made from the side of the
automatic disconnect connected to the
electric power train or to the rest of the
electric power train if the high voltage
source is a component contained in the
power train. For a high voltage source
that has an automatic disconnect that is
not physically contained within itself,
the electrical isolation measurement
after the test is made from both the high
voltage source side of the automatic
disconnect and from the side of the
automatic disconnect connected to the
electric power train or to the rest of the
electric power train if the high voltage
source is a component contained in the
power train.
*
*
*
*
*
E:\FR\FM\29JYR1.SGM
29JYR1
Federal Register / Vol. 76, No. 146 / Friday, July 29, 2011 / Rules and Regulations
jlentini on DSK4TPTVN1PROD with RULES
S7.6.4 The voltage(s) is/are
measured as shown in Figure 2, and the
voltage(s) (V1) between the negative
side of the high voltage source and the
electrical chassis.
S7.6.5 The voltage(s) is/are
measured as shown in Figure 3, and the
voltage(s) (V2) between the positive side
of the high voltage source and the
electrical chassis.
S7.6.6 If V1 is greater than or equal
to V2, insert a known resistance (Ro)
between the negative side of the high
voltage source and the electrical chassis.
With the Ro installed, measure the
voltage (V1′) as shown in Figure 4
between the negative side of the high
voltage source and the electrical chassis.
Calculate the electrical isolation
resistance (Ri) according to the formula
shown. Divide Ri (in ohms) by the
working voltage of the high voltage
source (in volts) to obtain the electrical
isolation (in ohms/volt).
S7.6.7 If V2 is greater than V1, insert
a known resistance (Ro) between the
positive side of the high voltage source
and the electrical chassis. With the Ro
installed, measure the voltage (V2′) as
shown in Figure 5 between the positive
side of the high voltage source and the
electrical chassis. Calculate the
electrical isolation resistance (Ri)
according to the formula shown. Divide
VerDate Mar<15>2010
17:45 Jul 28, 2011
Jkt 223001
Ri (in ohms) by the working voltage of
the high voltage source (in volts) to
obtain the electrical isolation (in ohms/
volt).
S7.7 Voltage measurement. For the
purpose of determining the voltage level
of the high voltage source specified in
S5.3(b), voltage is measured as shown in
Figure 1. Voltage Vb is measured across
the two terminals of the voltage source.
Voltages V1 and V2 are measured
between the source and the electrical
chassis. For a high voltage source that
has an automatic disconnect that is
physically contained within itself, the
electrical isolation measurement after
the test is made from the side of the
automatic disconnect connected to the
electric power train or to the rest of the
electric power train if the high voltage
source is a component contained in the
power train. For a high voltage source
that has an automatic disconnect that is
not physically contained within itself,
the electrical isolation measurement
after the test is made from both the high
voltage source side of the automatic
disconnect and from the side of the
automatic disconnect connected to the
electric power train or to the rest of the
electric power train if the high voltage
source is a component contained in the
power train.
PO 00000
Frm 00054
Fmt 4700
Sfmt 4725
S8. Test procedure for on-board
electrical isolation monitoring system.
Prior to any impact test, the
requirements of S5.4 for the on-board
electrical isolation monitoring system
shall be tested using the following
procedure.
(1) The electric energy storage device
is at the state-of-charge specified in
S7.1.
(2) The switch or device that provides
power from the high voltage system to
the propulsion motor(s) is in the
activated position or the ready-to-drive
position.
(3) Determine the isolation resistance,
Ri, of the high voltage source with the
electrical isolation monitoring system
using the procedure outlined in S7.6.2
through S7.6.7.
(4) Insert a resistor with resistance Ro
equal to or greater than 1/(1/(95 times
the working voltage of the high voltage
source)¥1/Ri) and less than 1/(1/(100
times the working voltage of the high
voltage source)¥1/Ri) between the
positive terminal of the high voltage
source and the electrical chassis.
(5) The electrical isolation monitoring
system indicator shall display a warning
visible to the driver seated in the
driver’s designated seating position.
BILLING CODE 4910–59–P
E:\FR\FM\29JYR1.SGM
29JYR1
ER29JY11.008</GPH>
45450
ER29JY11.010</GPH>
45451
VerDate Mar<15>2010
16:04 Jul 28, 2011
Jkt 223001
PO 00000
Frm 00055
Fmt 4700
Sfmt 4725
E:\FR\FM\29JYR1.SGM
29JYR1
ER29JY11.009</GPH>
jlentini on DSK4TPTVN1PROD with RULES
Federal Register / Vol. 76, No. 146 / Friday, July 29, 2011 / Rules and Regulations
VerDate Mar<15>2010
Federal Register / Vol. 76, No. 146 / Friday, July 29, 2011 / Rules and Regulations
16:04 Jul 28, 2011
Jkt 223001
PO 00000
Frm 00056
Fmt 4700
Sfmt 4725
E:\FR\FM\29JYR1.SGM
29JYR1
ER29JY11.011</GPH>
jlentini on DSK4TPTVN1PROD with RULES
45452
Issued on: July 25, 2011.
David L. Strickland,
Administrator.
[FR Doc. 2011–19216 Filed 7–28–11; 8:45 am]
BILLING CODE 4910–59–C
DEPARTMENT OF TRANSPORTATION
National Highway Traffic Safety
Administration
49 CFR Part 575
[Docket No. NHTSA–2010–0025]
RIN 2127–AK51
New Car Assessment Program (NCAP);
Safety Labeling
National Highway Traffic
Safety Administration (NHTSA),
Department of Transportation (DOT).
ACTION: Final rule.
AGENCY:
New passenger vehicles
manufactured on or after September 1,
2007 must be labeled with safety rating
information published by the National
Highway Traffic Safety Administration
(NHTSA) under its New Car Assessment
Program (NCAP). This information is
required by statute to be part of the
jlentini on DSK4TPTVN1PROD with RULES
SUMMARY:
VerDate Mar<15>2010
16:04 Jul 28, 2011
Jkt 223001
Monroney (automobile price sticker)
label. Effective beginning in model year
2011 passenger vehicles, NHTSA
enhanced the NCAP ratings program to
include, among other things, the
incorporation of an overall vehicle score
that is derived from the vehicle’s frontal
crash, side crash, and rollover resistance
ratings. This final rule amends NHTSA’s
regulation on vehicle labeling of safety
rating information to reflect the
enhanced NCAP ratings program.
DATES: The final rule is effective August
29, 2011.
Petitions for Reconsideration: If you
wish to petition for reconsideration of
this rule, your petition must be received
by September 12, 2011.
ADDRESSES: If you wish to petition for
reconsideration of this rule, you should
refer in your petition to the docket
number of this document and submit
your petition to: Administrator,
National Highway Traffic Safety
Administration, 1200 New Jersey
Avenue, SE., West Building,
Washington, DC 20590.
The petition will be placed in the
docket. Anyone is able to search the
electronic form of all documents
received into any of our dockets by the
name of the individual submitting the
PO 00000
Frm 00057
Fmt 4700
Sfmt 4700
45453
comment (or signing the comment, if
submitted on behalf of an association,
business, labor union, etc.). You may
review DOT’s complete Privacy Act
Statement in the Federal Register
published on April 11, 2000 (Volume
65, Number 70; Pages 19477–78).
For access to the docket to read
background documents or comments
received, go to https://
www.regulations.gov and follow the
online instructions for accessing the
docket. You may also visit DOT’s
Docket Management Facility, 1200 New
Jersey Avenue, SE., West Building
Ground Floor, Room W12–140,
Washington, DC 20590–0001 for on-line
access to the docket.
FOR FURTHER INFORMATION CONTACT: For
non-legal issues, you may contact Ms.
Jennifer N. Dang, Office of
Crashworthiness Standards (Telephone:
202–366–1740) (Fax: 202–493–2739).
For legal issues, you may call Mr. Steve
Wood, Office of the Chief Counsel
(Telephone: 202–366–2992) (Fax: 202–
366–3820). You may send mail to both
of these officials at the National
Highway Traffic Safety Administration,
1200 New Jersey Avenue, SE., West
Building, Washington, DC 20590–0001.
SUPPLEMENTARY INFORMATION:
E:\FR\FM\29JYR1.SGM
29JYR1
ER29JY11.012</GPH>
Federal Register / Vol. 76, No. 146 / Friday, July 29, 2011 / Rules and Regulations
]]>Agencies
[Federal Register Volume 76, Number 146 (Friday, July 29, 2011)]
[Rules and Regulations]
[Pages 45436-45453]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2011-19216]
[[Page 45436]]
=======================================================================
-----------------------------------------------------------------------
DEPARTMENT OF TRANSPORTATION
National Highway Traffic Safety Administration
49 CFR Part 571
[Docket No. NHTSA-2011-0107]
RIN 2127-AK80
Federal Motor Vehicle Safety Standards; Electric-Powered
Vehicles; Electrolyte Spillage and Electrical Shock Protection
AGENCY: National Highway Traffic Safety Administration (NHTSA),
Department of Transportation (DOT).
ACTION: Final rule; response to petitions for reconsideration.
-----------------------------------------------------------------------
SUMMARY: This document responds to petitions for reconsideration of a
final rule issued by this agency on June 14, 2010. This final rule
amended the electrical shock protection requirements to facilitate the
development and introduction of fuel cell vehicles (a type of electric-
powered vehicle) and the next generation of hybrid and battery electric
powered vehicles. This document addresses issues raised in the
petitions for reconsideration relating to the scope and applicability
of the standard, the definitions in the standard, the retention
requirements for electric energy storage/conversion systems, the
electrical isolation requirements, the test specifications and
requirements for electrical isolation monitoring, the state-of-charge
of electric energy storage devices prior to the crash tests, a proposed
protective barrier compliance option for electrical safety, the use of
alternative gas to crash test hydrogen fuel cell vehicles, and a
proposed low-energy compliance option for electrical safety.
DATES: The effective date of this final rule is September 1, 2011 with
optional early compliance.
Petitions for reconsideration: Petitions for reconsideration of
this final rule must be received not later than September 12, 2011.
ADDRESSES: Petitions for reconsideration of this final rule must refer
to the docket and notice number set forth above and be submitted to the
Administrator, National Highway Traffic Safety Administration, 1200 New
Jersey Avenue, SE., Washington, DC 20590.
FOR FURTHER INFORMATION CONTACT: For technical issues: Ms. Shashi
Kuppa, Office of Crashworthiness Standards (telephone: 202-366-3827)
(fax: 202-493-2990), NVS-113.
For legal issues: Mr. Jesse Chang, Office of the Chief Counsel
(telephone: 202-366-2992) (fax: 202-366-3820), NCC-112.
The mailing address for these officials is: National Highway
Traffic Safety Administration, 1200 New Jersey Avenue, SE., Washington,
DC 20590.
SUPPLEMENTARY INFORMATION:
Table of Contents
I. Background--June 14, 2010 Final Rule
II. Petitions for Reconsideration
III. Summary of Revisions to the June 14, 2010 Final Rule
IV. Agency Response and Rationale
a. Application
b. Definitions
c. Electric Energy Storage/Conversion System Retention
d. Electrical Safety
e. Electrical Isolation Monitoring
f. Electric Energy Storage Device State-of-Charge
g. Physical Barrier Compliance Option for Electrical Safety
h. Use of Alternative Gas for Testing Hydrogen Fuel Cell
Vehicles
i. Low-Energy Compliance Option for Electrical Safety
V. Rulemaking Analyses and Notices
VI. Regulatory Text
I. Background--June 14, 2010 Final Rule
On June 14, 2010, NHTSA issued a final rule which amended the
electrical shock protection requirements of Federal Motor Vehicle
Safety Standard (FMVSS) No. 305, ``Electric-powered vehicles;
electrolyte spillage and electrical shock protection,'' to facilitate
the development and introduction of fuel cell vehicles, a type of
electric-powered vehicle, and the next generation of hybrid and battery
electric powered vehicles (75 FR 33515, NHTSA Docket No. 2010-0021).
The final rule revised the agency's standard regulating electrolyte
spillage and electrical shock protection for electric-powered vehicles
to align it more closely with the April 2005 version of the Society of
Automotive Engineers (SAE) J1766--``Recommended Practice for Electric
and Hybrid Electric Vehicle Battery Systems Crash Integrity Testing.''
This rule also provided greater flexibility by allowing
manufacturers to meet the requirements of FMVSS No. 305 by designing
their electrically powered vehicles so that, in the event of a crash,
the electric energy storage, conversion, and propulsion systems are
either electrically isolated from the vehicle's chassis or their
voltage is below specified levels considered safe from electric shock
hazards. Since the physiological impacts of direct current (DC) are
less than those of alternating current (AC), the final rule specified
lower electrical isolation requirements for certain DC components (100
ohms/volt) than for AC components (500 ohms/volt).
In addition, the final rule included new definitions, made changes
to existing definitions of terms used in the standard, changed the
energy storage/conversion device retention requirements, specified a
low voltage option for achieving electrical safety, and required
monitoring of the isolation resistance of DC high voltage sources that
comply with the 100 ohms/volt electrical isolation requirement. The
agency also established an effective date on September 1 in the year
after the final rule was published (or September 1, 2011) with optional
early compliance.
II. Petitions for Reconsideration
Subsequently, NHTSA received petitions for reconsideration of the
June 14, 2010 final rule from the Alliance of Automobile Manufacturers
(Alliance),\1\ Technical Affairs Committee of the Association of
International Automobile Manufacturers, Inc. (AIAM) \2\ and Honda Motor
Co., Ltd. (Honda). Ford Motor Company (Ford) also presented an analysis
to the agency in support of the Alliance's petition for reconsideration
regarding the issue of electric energy storage system state-of-charge
prior to the crash tests specified in the standard.\3\ In addition, on
December 21, 2010, the Alliance, AIAM, and Honda submitted a joint
letter as supplementary information to their petitions for
reconsideration stating their support for the definitions used in the
draft documents on electrical safety for a forthcoming global technical
regulation (GTR) on hydrogen fuel cell vehicle safety.
---------------------------------------------------------------------------
\1\ The Alliance is a trade association whose members are: BMW
Group, Chrysler Group LLC, Ford Motor Company, General Motors LLC,
Jaguar Land Rover, Mazda, Mercedes-Benz USA, Mitsubishi Motors,
Porsche, Toyota, and Volkswagen.
\2\ The AIAM petition stated it is a trade association whose
Technical Affairs Committee members include: American Honda Motor
Co., American Suzuki Motor Corp., Aston Martin Lagonda of North
America, Inc., Ferrari North America, Inc., Hyundai Motor America,
Isuzu Motors America LLC, Kia Motors America, Inc., Mahindra &
Mahindra Ltd., Maserati North America, Inc., McLaren Automotive
Ltd., Nissan North America, Inc., Peugeot Motors of America, Subaru
of America, ADVICS North America, Inc., Delphi Corporation, Denso
International America, Inc., and Robert Bosch Corporation. In
January 2011, AIAM was renamed as the Association of Global
Automakers (Global Automakers). Nonetheless, our response to
petitions of the final rule will still refer to AIAM.
\3\ Ford presented an analysis of the state-of-charge of the
energy storage system prior to the crash tests in a meeting with
NHTSA personnel on May 26, 2010. This presentation was posted to the
Docket No. NHTSA-2010-0021 on September 1, 2010.
---------------------------------------------------------------------------
The petitioners generally sought increased clarity by raising
issues
[[Page 45437]]
regarding the definitions, test specifications, and performance
requirements in this rule. Specifically, the petitioners raised
questions regarding the applicability and scope of the standard, the
definitions of terms used, the electric energy storage/conversion
system retention requirements, the electrical isolation requirements,
the requirements and test specifications for electrical isolation
monitoring systems, the electric energy storage device state-of-charge,
the protective barrier as a compliance option for electrical safety,
and the use of alternative gas for testing hydrogen fuel cell vehicles.
III. Summary of Revisions to the June 14, 2010 Final Rule
This document responds to all the petitions for reconsideration of
the June 14, 2010 final rule. Specifically, this final rule makes the
following changes to the June 14, 2010 final rule:
Revises the ``Application'' section to indicate that the
standard applies only to vehicles that use high voltage electrical
components for propulsion power rather than to any vehicle that has
high voltage electrical components.
Clarifies the definitions used in the June 14, 2010 final
rule for electrical isolation, electric energy storage/conversion
system, electric energy storage device, propulsion system, and high
voltage source.
Adds further clarity by including new definitions for
automatic disconnect, electric energy storage/conversion device,
electrical chassis, and electric power train.
Revises the application of retention requirements from
energy storage/conversion ``systems'' to energy storage/conversion
``devices.''
Clarifies the electric energy storage/conversion device
retention requirements to indicate that during and after the test, the
device(s) shall remain attached to the vehicle by at least one
component anchorage, bracket, or any structure that transfers loads
from the device to the vehicle structure and those located outside the
occupant compartment shall not enter the occupant compartment.
Clarifies the electrical safety requirements to specify
that AC high voltage sources with electrical isolation monitoring
require 500 ohms/volt electrical isolation.
Specifies the voltage measurement locations for high
voltage sources with and without automatic disconnects in the test
procedures for determining electrical safety.
Revises the electrical isolation monitoring requirement by
deleting the term ``continuous'' in ``continuous monitoring'' and
including a range in resistance of the external resistor selected in
the test procedure to evaluate the performance of the monitoring
system.
Clarifies the specification for the state-of-charge of
electric energy storage devices before the crash tests to be at the
maximum state-of-charge in accordance with the vehicle manufacturer's
recommended charging procedures, as stated in the vehicle owner's
manual or on a label permanently affixed to the vehicle, or at 95
percent of the maximum capacity of the electric energy storage device
if no such recommendation is made.
Revises the regulatory text and Figures 1-5 to utilize the
new terms added to the definitions section.
IV. Agency Response and Rationale
After reviewing the petitions for reconsideration, NHTSA is
responding to each issue raised by the petitioners as follows.
a. Application
The June 14, 2010 final rule defined the scope of FMVSS No. 305 by
stating the following in paragraph S3 Application:
S3. Application. This standard applies to passenger cars, and to
multipurpose passenger vehicles, trucks, and buses that have a GVWR
of 4,536 kg or less, that use electrical components with working
voltages more than 60 volts direct current (VDC) or 30 volts
alternating current (VAC), and whose speed attainable over a
distance of 1.6 km on a paved level surface is more than 40 km/h.
Both the Alliance and the AIAM noted that in section ``S3
Application'' of the final rule, the agency omitted the word
``propulsion'' and that this was not consistent with the language in
the NPRM.\4\ Both organizations argued that the omission of the word
``propulsion'' could be interpreted to encompass all electrical systems
that are not within the scope of FMVSS No. 305 (e.g. high intensity
discharge (HID) headlamps, engine ignition systems, fuel injectors,
etc).
---------------------------------------------------------------------------
\4\ 72 FR 57266; Notice of Proposed Rulemaking; October 9, 2007.
---------------------------------------------------------------------------
The Alliance proposed that the scope be remedied by adding the word
``propulsion'' in the application section, S3. The AIAM indicated in
its petition that it supported the language proposed by the Alliance.
The language proposed by the Alliance is as follows:
S3 Application. This standard applies to passenger cars, and to
multipurpose passenger vehicles, trucks and buses with a GVWR of
4536 kg or less, that use electrical propulsion components with
working voltages more than 60 volts direct current (VDC) or 30 volts
alternating current (VAC), and whose speed attainable over a
distance of 1.6 km on a paved level surface is more than 40 km/h.
(emphasis in the original)
NHTSA's Response: We agree with the Alliance that by omitting the
word ``propulsion'' in S3 of the final rule, the standard encompasses
vehicles and electrical systems that were not intended for application
of FMVSS No. 305. Since the agency is not aware of any cases of
injuries/fatalities from shock in non-electrically powered vehicles
with other high voltage components such as HID headlamps, ignition
systems, or fuel injectors, this final rule adopts the language for S3
Application as proposed by the Alliance. This new version of the
regulatory text ensures that FMVSS No. 305 will not extend to the
aforementioned vehicles and vehicle components for which the standard
was not intended to apply.
b. Definitions
The June 14, 2010 final rule adopted new definitions into FMVSS No.
305. In a joint letter submitted by the Alliance, AIAM, and Honda, the
organizations acknowledged that while the current FMVSS No. 305
definitions were based on SAE J1766, the subsequent promulgation of
FMVSS No. 305 and the development of an international GTR on hydrogen
fuel cell vehicle safety have largely rendered aspects of the SAE
standard obsolete. The organizations requested that the agency
incorporate, into FMVSS No. 305, the definitions contained in the draft
electrical safety requirements developed by the Electric Safety (ELSA)
working group in September 2010 as part of the draft GTR. Given this
request from the aforementioned organizations, the rapid development of
technology in electrical and fuel cell vehicles resulting in numerous
changes in terminology and their associated definitions, and
significant uncertainty among the relevant stakeholders as to the
proper interpretation of many of the definitions adopted by the June
14, 2010 final rule, today's final rule seeks to clarify and update
many of the definitions through additional language and/or adopting
similar language from the draft ELSA electrical safety document
(henceforth referred to as the ELSA document) where appropriate.\5\ In
the following
[[Page 45438]]
sections, we will address each of the definitions added or amended by
today's final rule in turn.
---------------------------------------------------------------------------
\5\ Electrical Safety Provisions for Vehicles Post Crash ELSA-8-
05 Rev. 01 (Draft agreed during 8th ELSA Meeting, Aug 31-Sept 2,
2010) https://www.unece.org/trans/doc/2010/wp29grsp/ELSA-8-05r1e.pdf.
---------------------------------------------------------------------------
1. Automatic Disconnect
One appropriate area for adopting similar language from the ELSA
document is the definition for ``automatic disconnect.'' Since the June
14, 2010 final rule did not define ``automatic disconnect,'' the agency
is concerned that it may result in ambiguity regarding the location of
voltage measurements taken pursuant to paragraph S7.6.1 (as further
discussed later in this document). Therefore, today's final rule
includes a definition for automatic disconnect, derived from the ELSA
document, which states that ``automatic disconnect'' means a device
that when triggered, conductively separates a high voltage source from
the electric power train or the rest of the electric power train.
2. Electrical Isolation
In the final rule, we defined ``Electrical isolation'' as ``the
electrical resistance between the vehicle high voltage source and any
vehicle conductive structure.'' The Alliance stated that the definition
for ``electrical isolation'' as defined in the final rule could present
difficulties because ``any vehicle conductive structure'' could be
interpreted to include the high voltage source itself, and a high
voltage source cannot be isolated from itself. The Alliance, therefore,
petitioned to revise the definition so that the electrical isolation is
between the vehicle high voltage source and the ``vehicle chassis
electricity-conducting structure.''
NHTSA's Response: The agency agrees that that the language ``any
conductive structure'' should be clarified to indicate which vehicle
components are required to be isolated from the high voltage source.
However, we decline to adopt the Alliance's proposed term, ``vehicle
chassis electricity-conducting structure,'' since it also lacks
sufficient clarification on which vehicle components will be included
by this term. For example, it is unclear whether the term includes
other conducting structures in the vehicle such as the enclosures of
high voltage sources. To address this issue, this final rule clarifies
what the high voltage source is electrically isolated from by including
a definition for a new term that has been proposed in the draft ELSA
document. Based on the language of the ELSA document, a definition for
``electrical chassis'' is included in today's final rule as follows:
Electrical chassis means conductive parts of the vehicle whose
electrical potential is taken as reference and which are: (1)
conductively linked together, and (2) not high voltage sources
during normal vehicle operation.
Since this definition of electrical chassis includes vehicle
designs with multiple electrical chassis, this final rule clarifies the
definition of electrical isolation to mean the electrical resistance
between a given high voltage source and any electrical chassis of the
vehicle. Further, in order to be consistent with the manner in which
electrical isolation is determined in S7.6.6 and S7.6.7 of the
electrical isolation test procedure and with the units of electrical
isolation specified in S5.3(a), today's final rule also clarifies the
definition of electrical isolation of a high voltage source to mean the
electrical isolation resistance of the high voltage source divided by
the working voltage of the high voltage source. Applying these
corrections, along with the new definition of electrical chassis,
today's final rule amends the definition for electrical isolation to
read as follows:
Electrical isolation of a high voltage source in the vehicle
means the electrical resistance between the high voltage source and
any of the vehicle's electrical chassis divided by the working
voltage of the high voltage source.
The agency believes the changes made in today's final rule address
the Alliance's concern about the broad term ``any vehicle conductive
structure.'' Specifically, this definition ensures that the term
``vehicle conductive structure'' is not construed to include the high
voltage source itself as the new definition for ``electrical chassis''
explicitly excludes high voltage sources. In addition, the use of these
definitions more closely aligns FMVSS No. 305 with the definitions
proposed by the ELSA working group and clarifies what types of
components would be considered part of the chassis. For example, under
these definitions, the electrical chassis includes the enclosures of
the high voltage sources which are conductively linked to other
conductive parts of the vehicle whose electrical potential is taken as
a reference.
3. Electric Energy Storage/Conversion/Power Generating System &
Electric Energy Storage Device
Before the NPRM in this current rulemaking, FMVSS No. 305 contained
a definition for the term ``Battery system component.'' In the NPRM,
the agency proposed replacing the definition of ``Battery system
component'' with ``Energy storage system.'' The agency changed the
definition in the final rule after considering the joint Alliance/AIAM
comment to the NPRM to include ``energy conversion system'' as part of
the definition for ``Energy storage system.'' In their comment, the
Alliance/AIAM stated that fuel cell systems were conversion systems and
should also comply with the retention requirements. NHTSA agreed and
redefined ``Energy storage system'' as ``Electric energy storage/
conversion/power generating system.'' The term ``power generating
system'' was also included to align FMVSS No. 305 more closely with the
terminology used in SAE J1766. Thus, the June 14, 2010 final rule
defined ``Electric Energy Storage/Conversion/Power Generating System''
as follows:
Electric energy storage/conversion/power generating system means
the components comprising, but not limited to, the vehicle's high
voltage battery system, capacitor system, or fuel cell system, and
rechargeable energy storage systems. These include, but are not
limited to, the battery or capacitor modules, interconnects, venting
systems, battery or capacitor restraint devices, and electric energy
storage boxes or containers that hold the individual battery or
capacitor modules. Hydrogen system components of fuel cell vehicles,
such as the hydrogen tanks and hydrogen tubes, are not included in
the electric energy storage/conversion system.
We received multiple petitions requesting that the agency
reconsider the ``Electric energy storage/conversion/power generating
system'' definition. The Alliance stated that this definition is overly
broad and includes energy storage systems beyond those used for
propulsion power. The Alliance recommended that the definition be
modified to utilize the following text: Electric energy storage/
conversion/power generating system ``means the electric energy sources
for the propulsion system comprising, but not limited to, the vehicle's
high voltage battery system * * *'' (emphasis in original).
The AIAM and Honda had further concerns about the definition. The
AIAM stated that the definition is not used consistently throughout the
standard or even within the definition itself. For example, the AIAM
noted that the last sentence of the definition for electrical energy
storage/conversion/power generating system (which refers to hydrogen
system components of fuel cell vehicles) is only applicable to the
electric energy storage or conversion system parts of the definition
and not to the power generating system portion. Honda stated that the
combined definition may cause confusion to the reader.
Further, both the AIAM and Honda stated that various requirements
in
[[Page 45439]]
FMVSS No. 305 apply only to portions of the electric energy storage/
conversion/power generating system definition, creating confusion
regarding the applicability of various requirements in the standard.
The AIAM and Honda refer to fuel cell modules as an example of this
potential confusion. They noted that the retention requirements in
S5.2, as written, are applicable only to the electric energy storage
system and electric energy conversion system but are not applicable to
the electric power generating system. According to SAE J1766 (April,
2005), the term ``power generating system components'' is defined as
``the components comprising the high voltage power generating system in
an Electric, Fuel Cell or Hybrid vehicle. These include, but are not
limited to, generators, fuel cell modules, DC/DC converters and
interconnects.'' The AIAM and Honda stated that if the SAE definition
is used to determine the meaning of ``power generating system'' for
purposes of S5.2 retention requirements, it could be concluded that
fuel cell modules are exempt because S5.2 does not list ``power
generating system'' as requiring compliance with the retention
requirements. The AIAM and Honda do not believe that the agency
intended to exclude fuel cell modules from the retention requirements,
considering the potential occupant injury risk in a crash if fuel cell
modules became unattached. For clarity, both the AIAM and Honda
petitioned that the terms ``Electric energy storage system,''
``Electric energy conversion system'' and ``Electric power generating
system'' be defined separately.
NHTSA's Response: We agree with petitioners that the ``Electric
energy storage/conversion/power generating system'' definition should
be clarified in order to avoid confusion as to the applicability of
various requirements in FMVSS No. 305. In order to accomplish this
task, today's final rule utilizes three separate definitions. First, it
renames and makes adjustments to the language in the ``Electric energy
storage/conversion/power generating system'' definition in order to
reference the components that comprise the entire ``Electric energy
storage/conversion system.'' Second, today's final rule also adds a new
definition for ``Electric energy storage/conversion device'' in order
to help distinguish the instances in which the various requirements of
FMVSS No. 305 are to apply to an entire system as opposed to only
component devices. Finally, this rule also retains the ``Electric
energy storage device'' definition with minor revisions in order to
clarify the instances in which the test specifications of this rule
apply to the electric energy storage devices alone.
The agency also agrees with the Alliance petition that the
definition for ``electric energy storage/conversion/power generating
system'' should be specific to systems used for vehicle propulsion in
order to distinguish them from other electric energy storage systems
such as the auxiliary battery that is present on many hybrid/electric
vehicles and is currently not subject to the retention requirements
since it is typically of low mass and does not pose a safety hazard in
the existing fleet. Thus, we have made the appropriate modifications to
the three aforementioned definitions to indicate that the devices or
components covered by each definition are used for vehicle propulsion.
In order to further add clarity to this definition, this final rule
removes the reference to the term, ``power generating systems,'' from
the June 14, 2010 final rule definition of ``Electric energy storage/
conversion/power generating system.'' As ``power generating systems''
was included in the June 14, 2010 final rule definition in order to
more closely align FMVSS No. 305 with the (now obsolete) SAE Standard
J1766, the agency believes that there is no longer a purpose for
including ``power generating systems'' in the ``Electric energy
storage/conversion/power generating system'' definition. Thus, today's
final rule simply defines ``Electric energy storage/conversion
system.''
In addition, we agree with the AIAM that the last sentence of the
``Electric energy storage/conversion/power generating system''
definition in the June 14, 2010 final rule can cause confusion. We
believe that the last sentence of that definition, which states that
``[h]ydrogen system components of fuel cell vehicles, such as the
hydrogen tanks and hydrogen tubes, are not included in the electric
energy storage/conversion system,'' is superfluous. Thus, in further
advancing the goal of clarity in the ``Electric energy storage/
conversion system'' definition, we have deleted the aforementioned
sentence. Under the definition in today's final rule, fuel cells are a
type of energy conversion system and the agency will continue to refer
to high voltage batteries, capacitors, and fuel cell systems as
``energy storage/conversion systems.''
Thus, the final rule defines ``Electric energy storage/conversion
system'' as follows:
Electric energy storage/conversion system means an assembly of
electrical components that stores or converts electrical energy for
vehicle propulsion. This includes, but is not limited to, high
voltage batteries or battery packs, fuel cell stacks, rechargeable
energy storage systems, capacitor modules, inverters, interconnects,
and venting systems.
Additionally, today's final rule adds a new definition for
``Electric energy storage/conversion device.'' We take note that the
retention requirements of S5.2 of the June 14, 2010 final rule apply to
all components that fall under the broader ``Electric energy storage/
conversion system'' definition and that petitioners asked for
clarification to the ``Electric energy storage/conversion system''
definition, in part, to clarify the specific components that will be
subject to the retention requirements of paragraph S5.2. As further
discussed later in this document, petitioners are concerned that
``energy storage/conversion systems'' can include interconnects and
venting systems that are typically of low mass and need not be included
in the retention requirements because they are not a safety risk. Thus,
to make this distinction, today's final rule modifies paragraph S5.2 to
utilize the definition for ``electric energy storage/conversion
device'' and defines this term as follows:
Electric energy storage/conversion device means a high voltage
source that stores or converts energy for vehicle propulsion. This
includes, but is not limited to, a high voltage battery or battery
pack, fuel cell stack, rechargeable energy storage device, and
capacitor module.
Today's final rule also retains and amends the definition of
``Electric energy storage device'' from the June 14, 2010 final rule.
The June 14, 2010 final rule defined ``Electric energy storage device''
as follows:
Electric energy storage device means a high voltage source that
can store energy, such as a battery or capacitor modules.
The term, ``Electric energy storage device,'' is used in the
regulatory text to specify the state of charge of electric energy
storage devices before the vehicle crash test. While closely related to
the term ``Electric energy storage/conversion device,'' it does not
encompass conversion devices such as fuel cell stacks. Today's final
rule makes minor revisions to this definition in order to add clarity
and consistency with the two other definitions discussed in this
section by specifying that the electric energy storage devices under
consideration are used for vehicle propulsion. Thus, the definition of
electric energy storage device in today's final rule is amended as
follows:
[[Page 45440]]
Electric energy storage device means a high voltage source that
stores energy for vehicle propulsion. This includes, but is not
limited to, a high voltage battery or battery pack, rechargeable
energy storage device, and capacitor module.
Paragraphs S1 and S2 of today's final rule have also been amended
to reflect these new definitions.
4. High Voltage Source
The June 14, 2010 final rule included a definition of ``high
voltage source'' which is reproduced below:
High voltage source means any electric component that has a
working voltage greater than 30 VAC or 60 VDC.
The Alliance stated that in common usage, a ``voltage source'' is a
component capable of generating or storing electrical potential energy.
It argued that under the current definition, connectors and wiring
could be construed as voltage sources even though they are not capable
of generating or storing electrical energy. The Alliance petitioned
that the definition of ``high voltage source'' be revised to include
``any electric component that is capable of generating or storing a
voltage greater than 30 VAC or 60 VDC.''
NHTSA's Response: We agree with the Alliance that the current
definition of ``high voltage source'' should be clarified. However, we
cannot agree with the petitioner's proposal to limit the definition of
high voltage sources to only those components that are capable of
generating or storing electrical energy. Through the definition
included in the June 14, 2010 final rule, the agency did intend to
apply the electrical safety requirements to high voltage components,
including wiring and connectors that are part of the vehicle's electric
power train to ensure comprehensive electric shock protection.
However, we acknowledge that the definition in the June 14, 2010
final rule may not sufficiently distinguish the components included by
the ``high voltage source'' definition from those that are not
included. To clarify our intent today's final rule defines a high
voltage source as ``any electric component contained in the electric
power train or conductively connected to the electric power train that
has a working voltage greater than 30 VAC or 60 VDC (emphasis added).''
To further clarify this new definition, today's final rule adds a
definition for ``electric power train'' stating that it refers to ``an
assembly of electrically connected components which includes, but is
not limited to, electric energy storage/conversion systems and
propulsion systems.'' The definition of ``electrical energy storage/
conversion system'' is updated as described above. Further, today's
final rule makes minor revisions to the definition of ``propulsion
system'' to mean ``an assembly of electric or electro-mechanical
components or circuits that propel the vehicle using the energy that is
supplied by a high voltage source. This includes, but is not limited
to, electric motors, inverters/converters, electronic controllers, and
associated wire harnesses and connectors, and coupling systems for
charging rechargeable energy storage systems.''
These definitions adopt similar language from the Definitions and
the General sections of the ELSA document in order to both address the
Alliance, AIAM and Honda's suggestion that the agency adopt the ELSA
definitions where appropriate and to more clearly define the components
that are included under the definition of ``high voltage source.''
c. Electric Energy Storage/Conversion System Retention
In the NPRM, NHTSA proposed adjusting the ``Battery retention''
requirements of paragraph S5.2 to properly reflect the additional
energy storage devices that the updated standard intended to cover. The
adjustment to paragraph S5.2 accomplished this goal by proposing to
replace the word ``battery'' with the words ``energy storage device''
in S5.2 and adjust other portions of the regulatory text accordingly.
In the final rule, we amended the regulatory text based on the
considerations in the NPRM and in response to additional information
from a March 9, 2009 interpretation request from Hyundai. Hyundai
stated that the requirements of S5.2 allowed a battery module located
outside the passenger compartment to become dislodged as long as it
does not enter the occupant compartment, while a module that is located
within the occupant compartment must simply remain in the location in
which it is installed. Hyundai stated that this may not properly
address the intent of the standard in some circumstances.\6\ It argued
that in vehicles such as sport utility vehicles (SUV) or station
wagons, a battery module located inside the occupant compartment that
moves during impact due to the deformation of the floor but remains
firmly attached to its mounting, would technically fail the retention
requirement even though it would not pose a projectile hazard.
---------------------------------------------------------------------------
\6\ 65 FR 57985, FMVSS No. 305 Final Rule, September 27, 2000.
---------------------------------------------------------------------------
The agency elected to respond to Hyundai's interpretation request
in the June 14, 2010 final rule because the NPRM in this rulemaking had
already proposed to amend the language of S5.2. Thus, in the final
rule, the agency responded to that interpretation request stating
``The agency agrees that battery modules located inside the
occupant compartment technically may move a small amount from the
location from which they are installed during the impact tests. The
agency also agrees that battery modules located outside the occupant
compartment that partially move into the occupant compartment
because of structural deformation of the vehicle structure do not
impose a projectile hazard provided that they remain attached to the
mounting structure.\7\ Therefore, the agency concurs that battery
modules located outside the occupant compartment should be treated
in the same manner as those located inside the occupant compartment,
provided that they remain attached to their anchorages.''
---------------------------------------------------------------------------
\7\ 75 FR 33523.
Accordingly, the June 14, 2010 final rule revised the regulatory
---------------------------------------------------------------------------
text to read as follows:
S5.2 Electric energy storage/conversion system retention. All
components of the electric energy storage/conversion system must be
anchored to the vehicle. All component anchorages, including any
brackets or structures that transfer loads from the component to the
vehicle structure, shall remain attached to the vehicle structure at
all attachment locations during and after testing performed pursuant
to the procedures of S6 of this standard.
In its petition for reconsideration of the June 14, 2010 final
rule, the Alliance stated that the final rule's specification that all
component anchorages, shall remain attached to the vehicle structure at
all attachment locations is an overly broad requirement that goes
beyond the intent of assuring that battery system components do not
become separated from the vehicle. The Alliance stated that this
language could be interpreted as prohibiting a plastic tie-wrap used to
position a wiring harness to the vehicle from severing in a crash, a
requirement that is neither practicable nor necessary.
The Alliance and the AIAM further stated that some electric energy
storage/conversion systems, especially those which are located in the
engine compartment are protected from serious damage resulting from the
collision by absorbing the energy into deforming or even breaking
component mountings. The Alliance stated that this was analogous to
other energy management strategies, such as allowing steering
[[Page 45441]]
columns mountings to deform and break to keep the steering column away
from the driver of a vehicle during a severe crash. The Alliance stated
that a battery pack could be mounted to the vehicle at a dozen
attachment points, and the fact that one of these attachments severs
during a crash test would be inconsequential to the secure attachment
of the battery pack to the vehicle, yet violate the language of the
final rule. The AIAM stated that these system retention provisions may,
in some respects, be unnecessarily design restrictive and potentially
contrary to the interests of safety because rather than broadly
mandating that the battery remain attached to the vehicle, the
regulatory text places undue emphasis on the condition of individual
anchorages, brackets and structures.
Both the AIAM and Honda further argued that the intent of S5.2 was
to ensure that the battery modules would not become unattached and
become flying projectiles in a crash or subsequent rollover. Each
referenced the September 27, 2000 final rule establishing FMVSS No. 305
\8\ where the agency stated, ``We note that the intent of the proposed
requirements in S5.2 was to ensure that the battery modules would not
become unattached and become flying projectiles in a crash or
subsequent rollover.'' The AIAM stated that this regulatory goal is
best served by a requirement that broadly focuses on the overall
condition of the battery module (whether it remains attached to the
vehicle and has not intruded into the passenger compartment) rather
than the condition of the individual anchorages.
---------------------------------------------------------------------------
\8\ 65 FR 57985.
---------------------------------------------------------------------------
Finally, the AIAM and Honda also stated that there are many smaller
components that paragraph S5.2 in the June 14, 2010 final rule applies
to, such as ducts or vents, which may become unattached. They argued
that the occupant injury risk from such components of the energy
storage/conversion system is very low, given their small mass and that
there are no comparable requirements for internal combustion engine
(ICE) vehicles. The AIAM and Honda stated that in order to exclude low
mass components of the energy storage/conversion system, such as ducts
and vents, the retention requirements should apply only to energy
storage/conversion devices rather than to energy storage/conversion
systems.
Each of the petitioners had different strategies for amending the
requirements for electric energy storage/conversion system retention.
The Alliance petitioned that in order to avoid unnecessary design
limitations while achieving protection from both physical damage and
electrical shock, the following language be adopted for S5.2 of FMVSS
No. 305:
``The following requirements shall be met during and after
testing performed pursuant to the procedures of S6 of this standard:
1. Energy storage/conversion system components shall remain
secured to the vehicle, and
2. For energy storage/conversion system components located
outside the passenger compartment, such components shall not enter
the passenger compartment airspace.''
The Alliance also requested that if the agency does not agree with the
proposed language, the agency revert to the previous language of S5.2.
The AIAM petitioned the agency to amend S5.2 to read as follows:
``S5.2 Electric energy storage/conversion device(s) retention.
Electric energy storage/conversion devices must remain attached to
the vehicle during and after testing performed pursuant to the
procedures of S6 of this standard.''
Honda petitioned to amend S5.2 as follows:
``S5.2 Electric energy storage/conversion devices(s) retention.
The electric energy storage/conversion device(s) must remain
attached to the vehicle by anchorages, brackets, or structures that
transfer loads from the device(s) to the vehicle structure during
and after testing performed pursuant to the procedures of S6 of this
standard.''
NHTSA's Response: We agree with the comments from the Alliance,
AIAM, and Honda suggesting that the changes to the retention
requirement in the June 14, 2010 final rule may be overly broad. We
acknowledge that increased crash protection for energy storage/
conversion systems can be achieved through the deformation or breaking
of certain component mounting/anchorages to absorb the crash energy. We
further acknowledge that the language in the June 14, 2010 final rule
can be construed to include plastic tie-wraps used to position a wiring
harness which are not consequential towards the overall condition of
the energy storage/conversion systems.
However, we decline to adopt the regulatory text proposed by
petitioners because we are concerned with ensuring that the final
standard is clear and objective. Thus, the agency does not believe that
the proposed language changes from the AIAM and the Alliance are
appropriate as they require that the electric energy storage/conversion
devices remain attached without offering any specifics on how the
agency would distinguish between a device that has ``remained
attached'' and one that has not. The regulatory text proposed by Honda
offers more information on what constitutes ``remaining attached'' by
indicating that the electric energy storage/conversion device must
remain attached via ``anchorages, brackets, or structures that transfer
loads from the device(s) to the vehicle.'' However, this approach
remains unclear as it does not specify how many anchorages, brackets,
or structures that transfer load must remain attached.
Thus, today's final rule addresses the considerations of ensuring
adequate crash protection, creating an objective standard, and enabling
industry designs that utilize anchorages to redirect crash forces by
establishing regulatory text which requires that the electric energy
storage/conversion devices remain attached to the vehicle by at least
one component anchorage, bracket, or any structure that transfer loads
from the component to the vehicle structure. Using this regulatory
text, the agency can afford the manufacturers the maximum amount of
flexibility to utilize the anchorages as a method for redirecting crash
forces in their vehicle designs while still ensuring that electric
energy storage/conversion devices do not become projectiles which can
potentially injure vehicle occupants. Further, the additional
regulatory text adds clarity and objectivity to the standard by
specifying how the agency will distinguish between devices that have
remained attached versus those that have not. Namely, the additional
text clarifies that this standard only requires that the electric
energy storage/conversion devices maintain a connection to the vehicle
structure at one or more load transferring point after it is tested in
accordance with the test procedures in S6.
However, since we are not requiring all component anchorages to
remain attached to the vehicle at all attachment locations, we believe
that the June 14, 2010 final rule's conclusion that there is no need to
treat devices inside the occupant compartment differently from those
outside the occupant compartment is no longer accurate. While we agree
with petitioners that the intent of the retention requirement, as
specified in the 2000 final rule, was to ensure that battery modules
would not become unattached and become flying projectiles in a crash or
subsequent rollover, this is not the only purpose of the retention
requirement. One of the purposes of FMVSS No. 305 is to reduce deaths
and injuries during and after a crash that occur from the intrusion of
electric energy storage/conversion devices into the occupant
compartment.
[[Page 45442]]
In the June 14, 2010 final rule, the S5.2 requirement that all
component anchorages remain attached to the vehicle structure at all
attachment locations ensured that the energy storage/conversion system
would not significantly intrude into the occupant compartment.
We recognize that, with the new regulatory text for S5.2 in today's
final rule, there may be an increased potential for electric energy
storage/conversion devices to partially detach from the vehicle
structure and intrude into the occupant compartment. To address this,
we are reintroducing the requirement that any electric energy storage/
conversion device located outside the occupant compartment not intrude
into the occupant compartment. However, we decline to use the term
``passenger compartment airspace'' as suggested by the Alliance. A
similar term ``occupant compartment air space'' was defined by the
agency in an interpretation letter \9\ of FMVSS No. 302, ``Flammability
of interior materials.'' Since FMVSS No. 305 addresses safety from
electrolyte spillage, electric shock, and intrusion of the energy
storage system, and does not address fire safety, the presence of
airspace is not relevant and we believe that ``occupant compartment''
is the more appropriate term for paragraph S5.2.
---------------------------------------------------------------------------
\9\ Interpretation to Mazda (North America) Inc.--H. Nayaka:
February 15, 1983. An ``occupant compartment air space'' is defined
as ``the space within the occupant compartment that normally
contains refreshable air.''
---------------------------------------------------------------------------
We also agree with Honda and the AIAM that the language of the June
14, 2010 final rule could be interpreted as unintentionally requiring
low mass components, such as ducts and vents, to remain attached to the
electric energy storage/conversion systems. As previously discussed,
today's final rule adds a new definition for ``electric energy storage/
conversion device,'' which includes a high voltage battery or battery
pack, capacitor modules, fuel cell stacks, and rechargeable energy
storage devices used for vehicle propulsion, but does not include low
mass components, such as ducts, vents, and wiring harnesses. As the
retention requirements of the final rule are amended in today's final
rule to apply to the electric energy storage/conversion device rather
than to the system, these changes address the concerns raised by the
AIAM and Honda by ensuring that the retention requirements do not apply
to low mass components.
In conclusion, the regulatory text in paragraph S5.2 has been
amended to read as follows:
S5.2 Electric energy storage/conversion device retention. During
and after each test specified in S6 of this standard:
(a) electric energy storage/conversion devices shall remain
attached to the vehicle by at least one component anchorage,
bracket, or any structure that transfers loads from the device to
the vehicle structure, and
(b) electric energy storage/conversion devices located outside
the occupant compartment shall not enter the occupant compartment.
d. Electrical Safety
1. Clarifying the Requirements in Paragraph S5.3
Paragraph S5.3 of the June 14, 2010 final rule requires that each
high voltage source in a vehicle must meet the electrical isolation
requirements of subparagraph (a) or the voltage level requirements of
subparagraph (b) after each test. The subsections state:
(a) The electric isolation between each high voltage source and
the vehicle chassis electricity-conducting structure must meet one
of the following:
(1) Electrical isolation must be greater than or equal to 500
ohms/volt for all DC high voltage sources without continuous
monitoring of electrical isolation during vehicle operation and for
all AC high voltage sources; or
(2) Electrical isolation must be greater than or equal to 100
ohms/volt for all DC high voltage sources with continuous monitoring
of electrical isolation, in accordance with the requirements of
S5.4, during vehicle operation.
(b) The voltage of the voltage source must be less than or equal
to 30 VAC for AC components or 60 VDC for DC components.
The Alliance stated that it believes that the agency has
inadvertently written the electrical safety requirements in the final
rule in a way that would permit compliance with S5.3(a)(2) as the sole
basis for complying with S5.3 in total. It noted that S5.3 states that
the vehicle must meet the electrical isolation requirements of
subparagraph (a) or the voltage requirements of subparagraph (b). It
further noted that if subparagraph (a) is chosen, the language permits
compliance to either subparagraph (1) or subparagraph (2), and if
subparagraph (2) is chosen, there are no isolation requirements
specified for AC high voltage sources. The Alliance requested
clarification on whether the agency intended to require 500 ohms/volt
isolation for AC sources in subparagraph (a) in both the subsidiary
options of subparagraph (a).
NHTSA's Response: NHTSA agrees with the Alliance that the
regulatory text in S5.3(a) could be interpreted to imply that for a
vehicle with continuous monitoring of electrical isolation, only the DC
high voltage components need to meet the 100 ohms/volt electrical
isolation and that there are no requirements for AC high voltage
components. This was clearly not the intent. We are amending the
regulatory text of S5.3(a) to indicate that the electrical isolation
between a given high voltage source and any electrical chassis of the
vehicle must be greater or equal to one of the following: (1) 500 ohms/
volt for an AC high voltage source, or (2) 500 ohms/volt for a DC high
voltage source without electrical isolation monitoring, or (3) 100
ohms/volt for a DC high voltage source with electrical isolation
monitoring during vehicle operation. In order to further clarify
paragraph S5.3, we have included references to specific portions of the
test procedures that apply to the electrical safety requirements. In
addition, the term ``vehicle chassis electricity conducting structure''
in S5.3 has been replaced by the term ``electrical chassis'' to
maintain consistency with the changes discussed earlier in this
document. In conclusion, today's final rule amends paragraph S5.3 as
follows:
S5.3 Electrical safety. After each test specified in S6 of this
standard, each high voltage source in a vehicle must meet the
electrical isolation requirements of subparagraph (a) or the voltage
level requirements of subparagraph (b).
(a) The electrical isolation of the high voltage source,
determined in accordance with the procedure specified in S7.6, must
be greater or equal to one of the following:
(1) 500 ohms/volt for an AC high voltage source; or
(2) 500 ohms/volt for a DC high voltage source without
electrical isolation monitoring during vehicle operation; or
(3) 100 ohms/volt for a DC high voltage source with electrical
isolation monitoring, in accordance with the requirements of S5.4,
during vehicle operation.
(b) The voltages V1, V2, and Vb of the high voltage source,
measured according to the procedure specified in S7.7, must be less
than or equal to 30 VAC for AC components or 60 VDC for DC
components.
2. Testing Procedures for S5.3(b) Low Voltage Option
The Alliance also stated in its petition that S5.3(b) of the final
rule adopted a low-voltage option for providing electrical isolation,
while S7.7 specifies the procedure for measuring the voltage. The
Alliance petitioned that, for purposes of clarity, the language
currently specified in S7.6.1 regarding voltage measurement locations
for the electrical isolation option be added to S7.7 for the low-
voltage option.
NHTSA's Response: The agency agrees with the Alliance that the
procedure to measure the voltage in S7.6.1 should be added to S7.7 for
the
[[Page 45443]]
purposes of improving clarity. However, we believe S7.6.1 needs to be
modified to utilize the new definitions adopted above and to clarify
the measurement procedure before its contents are added to S7.7. The
test procedures in paragraph S7.6.1 of the June 14, 2010 final rule
states:
For a vehicle that utilizes an automatic disconnect between the
high voltage source and the traction system that is physically
contained within the high voltage electric energy storage/
conversion/power generating system, the electrical isolation
measurement after the test is made from the traction-system side of
the automatic disconnect to the vehicle chassis electricity-
conducting structure. For a vehicle that utilizes an automatic
disconnect that is not physically contained within the high voltage
electric energy storage/conversion/power generating system, the
electrical isolation measurement after the test is made from both
the high voltage source side and from the traction-system side of
the automatic disconnect to the vehicle chassis electricity-
conducting structure.
As previously discussed, today's final rule has adopted new
definitions for ``electric power train'' and ``electrical chassis.''
Therefore, all instances of the term ``traction-system'' in S7.6.1 are
replaced by the term ``electric power train'' and all instances of the
term ``vehicle chassis electricity-conducting structure,'' are replaced
by the term ``electrical chassis.'' This final rule also amends the
definition for ``high voltage source'' to include electric components
contained in the electric power train and those connected to it. For
high voltage sources contained within the electric power train, the
regulatory text of S7.6.1 and S7.7 have been amended to indicate that
the electrical isolation measurement is made from the side of the
automatic disconnect that is connected to ``the rest of the electric
powertrain.'' In addition, the regulatory text of the June 14, 2010
final rule S7.6.1 indicates that the ``automatic disconnect'' only
applies to high voltage sources within the vehicle's energy storage/
conversion/power generating system. We believe that this regulatory
text may be misconstrued, since the intent of the agency was that the
specifications for the electrical isolation measurement locations with
respect to the automatic disconnects in S7.6.1 apply to each high
voltage source with automatic disconnects. Therefore, the regulatory
text of S7.6.1 in today's final rule is modified as follows and
incorporated into S7.7 as requested by the Alliance:
For a high voltage source that has an automatic disconnect that
is physically contained within itself, the electrical isolation
measurement after the test is made from the side of the automatic
disconnect connected to the electric power train or to the rest of
the electric power train if the high voltage source is a component
contained in the power train. For a high voltage source that has an
automatic disconnect that is not physically contained within itself,
the electrical isolation measurement after the test is made from
both the high voltage source side of the automatic disconnect and
from the side of the automatic disconnect connected to the electric
power train or to the rest of the electric power train if the high
voltage source is a component contained in the power train.
However, to ensure consistency and clarity of terminology, today's
final rule also revises the first sentence in S7.6.1 to indicate that
the electric energy storage/conversion system (rather than the high
voltage source) is connected to the vehicle's propulsion system to
enable the propulsion system to be energized when the vehicle ignition
is in the ``on'' position. A similar clarification is made in S7.2 by
replacing ``high voltage system'' (which is not defined in the
regulatory text) with ``electric energy storage/conversion system'' and
``propulsion motors'' with ``propulsion system.''
e. Electrical Isolation Monitoring
While the NPRM did not propose a requirement for electrical
isolation monitoring, we acknowledged in the NPRM that the petitioner
for rulemaking requested that FMVSS No. 305 allow for DC high voltage
sources to meet a 100 ohms/volt electrical isolation requirement when
coupled with electrical isolation monitoring. In the final rule, based
on our analysis of comments on the NPRM, we required that each DC high
voltage source meet 500 ohms/volt electrical isolation for vehicles
without continuous electrical isolation monitoring but allowed DC high
voltage sources to meet 100 ohms/volt electrical isolation if the
vehicle had continuous monitoring of electrical isolation during
vehicle operation. We required that the system must monitor its own
readiness and provide a warning display that must be clearly visible
from the driver's designated seating position for loss of isolation
when tested according to the test procedure in S8.
The agency stated its belief that electrical isolation monitoring
is especially needed for electrical components whose electrical
isolation may degrade over time such as fuel cell stacks in fuel cell
vehicles where the coolant may increase in conductivity during vehicle
service and thereby result in a reduction of electrical isolation.
Since it is anticipated that the 100 ohms/volt electrical isolation
requirement for DC high voltage components would likely be exercised
for the fuel cell stacks and other such electrical components whose
isolation may degrade over time, we included the need for isolation
monitoring of these components in the final rule.
In its petitions for reconsideration, Honda stated that the level
of protection against electric shock should be judged by the absolute
value of electrical isolation resistance. Honda argued that whether or
not the vehicle is equipped with an isolation monitor has no relation
to the possibility of electric shock resulting from touching the high
voltage bus after a crash. Honda proposed removing entire sections of
S5.4 and S8 related to isolation monitoring systems. Honda noted that
the 2009 SAE J2578 \10\ and the 2009 ISO 6469-3 \11\ draft standards do
not require electrical isolation monitoring for electrical components
with 100 ohms/volt electrical isolation and requested that the
electrical isolation monitoring requirements be removed to resolve the
differences between the FMVSS No. 305 and the SAE/ISO standards.
---------------------------------------------------------------------------
\10\ SAE J2578--Recommended practice for general fuel cell
vehicle safety, SAE J2578-2009-01, Society of Automotive Engineers,
https://standards.sae.org/j2578_200901/.
\11\ ISO 6469-3--Electrically propelled road vehicles--Safety
specification--Part 3: Protection of persons against electric shock,
2009, https://www.iso.org/iso/catalogue_detail?csnumber=45479.
---------------------------------------------------------------------------
Honda requested that if NHTSA decides not to remove the electrical
isolation monitoring requirement, it instead permit periodic electrical
isolation monitoring systems such as those that do not monitor the
electrical isolation during start-up of vehicle/system (until main
contactor is connected). Honda stated that the 2010 draft of ISO 6469-3
and the 2006 draft of ISO 23273-3 permit both continuous and periodic
electrical isolation measurements during vehicle operation and that
``periodic'' systems would also detect a failure in isolation and
appropriately warn the driver. Therefore, Honda proposed FMVSS No. 305
include the words ``or periodic'' after the word, ``continuous'' in
S5.3, S5.4 and S8.
Further, Honda stated that the electrical isolation monitoring
system only monitors the entire system during normal vehicle operation
and is not capable of independently monitoring each high voltage
source. Therefore, Honda requested that the agency clarify that the
electrical isolation monitoring system will not be required to
independently monitor each high voltage source by deleting the words
``For each continuously monitored DC
[[Page 45444]]
high voltage source,'' from the regulatory text in S5.4.
Finally, Honda stated that the test procedure to determine the
operation of isolation monitoring systems does not allow flexibility in
selecting the resistor that is inserted between the positive terminal
of the high voltage source and the vehicle chassis electric conducting
structure. Honda noted that, as prescribed, S8(4) requires inserting a
resistor with resistance equal to the calculated result 1/(1/(95 times
the working voltage of the high voltage source)--1/Ri) and does not
allow any flexibility. Honda petitioned to allow any higher resistor to
be used in the test procedure to determine if the isolation monitoring
system is operating correctly arguing that the stringency of the test
would not be compromised since higher resistance would provide a worse
case condition.
NHTSA's Response--While we agree with Honda that isolation
monitoring is intended to identify the possibility of deteriorated
isolation that occurs over time during the normal service life of the
vehicle and that an isolation monitor is not intended to guard against
the possibility of electric shock resulting from touching a high
voltage source after a crash, we do not agree that the requirement for
electrical isolation monitoring should be deleted from the standard.
The requirement that DC high voltage sources be monitored during
vehicle operation with an isolation monitoring system that displays a
warning for loss of electrical isolation is similar to the air bag
readiness indicator required by FMVSS No. 208, ``Occupant crash
protection.'' Neither the electrical isolation warning display
