Document ID: NHTSA-2016-0029-0004
Agency: nhtsa
Document Type: Proposed Rule
Title: Federal Motor Vehicle Safety Standards: Electric-Powered Vehicles; Electrolyte Spillage and Electrical Shock Protection
Posted Date: 2016-03-10T05:00Z

[Federal Register Volume 81, Number 47 (Thursday, March 10, 2016)]
[Proposed Rules]
[Pages 12647-12676]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2016-05187]

-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

National Highway Traffic Safety Administration

49 CFR Part 571

[Docket No. NHTSA-2016-0029]
RIN 2127-AL68

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: Notice of proposed rulemaking (NPRM).

-----------------------------------------------------------------------

SUMMARY: NHTSA is proposing to amend Federal Motor Vehicle Safety 
Standard (FMVSS) No. 305, ``Electric-powered vehicles: Electrolyte 
spillage and electrical shock protection,'' to adopt various electrical 
safety requirements in Global Technical Regulation (GTR) No. 13, 
``Hydrogen and fuel cell vehicles.'' To expand the standard's 
performance requirements beyond post-crash conditions, NHTSA proposes 
to adopt electrical safety requirements to protect against direct and 
indirect contact of high voltage

[[Page 12648]]

sources during everyday operation of electric-powered vehicles. Also, 
NHTSA proposes to adopt an optional method of meeting post-crash 
electrical safety requirements consistent with that set forth in GTR 
No. 13 involving use of physical barriers to prevent direct or indirect 
contact (by occupants or emergency services personnel) with high 
voltage sources. Today's proposal would facilitate the introduction of 
new technologies including hydrogen fuel cell vehicles and 48 volt mild 
hybrid technologies, and responds not only to GTR No. 13 but also to 
petitions for rulemaking from Toyota Motor North America Inc. (Toyota) 
and the Auto Alliance (Alliance).

DATES: Comments must be received on or before May 9, 2016.
    Proposed compliance date: We believe there is widespread 
conformance of vehicles to the proposed requirements. Accordingly, we 
propose that the compliance date for the amendments in this rulemaking 
action would be 180 days after the date of publication of the final 
rule in the Federal Register. We propose to permit optional early 
compliance with the amended requirements.

ADDRESSES: You may submit comments to the docket number identified in 
the heading of this document by any of the following methods:
     Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the online instructions for submitting 
comments.
     Mail: Docket Management Facility, M-30, U.S. Department of 
Transportation, West Building, Ground Floor, Rm. W12-140, 1200 New 
Jersey Avenue SE., Washington, DC 20590.
     Hand Delivery or Courier: West Building Ground Floor, Room 
W12-140, 1200 New Jersey Avenue SE., between 9 a.m. and 5 p.m. Eastern 
Time, Monday through Friday, except Federal holidays.
     Fax: (202) 493-2251.
    Regardless of how you submit your comments, please mention the 
docket number of this document.
    You may also call the Docket at 202-366-9324.
    Instructions: For detailed instructions on submitting comments and 
additional information on the rulemaking process, see the Public 
Participation heading of the Supplementary Information section of this 
document. Note that all comments received will be posted without change 
to http://www.regulations.gov, including any personal information 
provided.
    Privacy Act: Please see the Privacy Act heading under Rulemaking 
Analyses and Notices.

FOR FURTHER INFORMATION CONTACT: For technical issues, you may call 
William J. Sanchez, Office of Crashworthiness Standards (telephone: 
202-493-0248) (fax: 202-493-2990). For legal issues, you may call 
Deirdre Fujita, Office of Chief Counsel (telephone: 202-366-2992) (fax: 
202-366-3820). Address: National Highway Traffic Safety Administration, 
U.S. Department of Transportation, 1200 New Jersey Avenue SE., West 
Building, Washington, DC 20590.

SUPPLEMENTARY INFORMATION:

Table of Contents

I. Executive Summary
II. FMVSS No. 305
III. The Global Technical Regulation
    a. Overview of the Process
    b. Overview of GTR No. 13
    1. Electric Safety Requirements During Normal Vehicle Operation
    2. Electric Safety Requirements Post-Crash Test
    c. How does this proposal differ from GTR No. 13?
IV. Battelle Study and Developments
V. Toyota Petition for Rulemaking
VI. Alliance Petition for Rulemaking
VII. Overview of Proposed Rule
VIII. Proposal Addressing Safety During Normal Vehicle Operations
IX. Proposal Addressing Safety Post-Crash
X. Rulemaking Analyses and Notices
XI. Public Participation

I. Executive Summary

    NHTSA is issuing this NPRM as part of the agency's ongoing effort 
to harmonize vehicle safety standards under the Economic Commission for 
Europe 1998 Global Agreement (``1998 Agreement''). The efforts of the 
U.S. and other contracting parties to the 1998 Agreement culminated in 
the establishment of GTR No. 13, ``Hydrogen and fuel cell vehicles.'' 
NHTSA voted in June 2013 in favor of establishing GTR No. 13. In this 
NPRM, we are proposing requirements based on the electrical safety 
requirements of GTR No. 13. NHTSA will initiate rulemaking in the 
future on other aspects of GTR No. 13 directly pertaining to the fuel 
system integrity of hydrogen fuel cell vehicles.
    One purpose of FMVSS No. 305 is to reduce deaths and injuries from 
electrical shock. The standard requires vehicles with high voltage 
sources to meet certain performance criteria to protect vehicle 
occupants, rescue workers and others who may come in contact with the 
vehicle after a crash. Among other things, FMVSS No. 305 requires that 
after a crash, high voltage sources in a vehicle are either (a) 
electrically isolated from the vehicle's chassis or (b) 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 standard specifies lower minimum 
electrical isolation requirements for certain DC components (100 ohms/
volt) than for AC components (500 ohms/volt).
    GTR No. 13 also has requirements intended to reduce deaths and 
injuries from electrical shock. Unlike FMVSS No. 305, GTR No. 13 has 
requirements that reduce the risk of harmful electric shock during 
normal vehicle operation. This NPRM proposes to adopt those 
requirements to expand FMVSS No. 305's performance requirements beyond 
post-crash conditions. In addition, while the various post-crash 
compliance options in GTR No. 13 are similar to those in FMVSS No. 305, 
GTR No. 13 includes a compliance option for electrical vehicle safety 
that prevents direct and indirect contact of high voltage sources by 
way of ``physical barriers.'' NHTSA is now proposing to amend FMVSS No. 
305 to permit a physical barrier compliance option.\1\
---------------------------------------------------------------------------

    \1\ Our proposed physical barrier option varies slightly from 
GTR No. 13. GTR No. 13 provides contracting parties discretion in 
whether to propose the option in their domestic regulatory process. 
In our proposal today, we are not proposing to adopt GTR No. 13's 
physical barrier option. However, as further discussed, below, we 
are adopting a modified physical barrier option that we believe will 
also afford the compliance flexibility that GTR No. 13 seeks to 
provide, while at the same time providing a level of safety closer 
to the other post-crash compliance options. A small number of minor 
additional provisions are proposed as well. These additional 
provisions would not significantly alter our incorporation of GTR 
No. 13 and are consistent with the goal of incorporating a standard 
that is harmonized with other international standards.
---------------------------------------------------------------------------

    NHTSA tentatively believes that the by-product of adopting a 
physical barrier option would be more than harmonizing vehicle 
standards. Enhanced design innovation, reduced CO2 emissions 
and increased fuel economy would likely result. This proposal would 
facilitate the introduction of 48 volt mild hybrid technologies and 
hydrogen fuel cell vehicles, and responds not only to GTR No. 13 but 
also to petitions for rulemaking from Toyota and the Alliance.
    Petitioner Toyota believes that an additional compliance option 
that includes elements of the physical barrier option in GTR No. 13 is 
needed to allow hydrogen fuel cell vehicles (HFCVs) to be offered for 
sale in the U.S.\2\ HFCVs and other electric powered

[[Page 12649]]

vehicles operate with their DC high voltage sources (e.g. high voltage 
battery) connected to the AC high voltage sources (e.g. electric 
motor). In a moderate to severe crash (e.g., crash speeds at which an 
air bag would deploy), electric powered vehicles are generally designed 
with an automatic disconnect mechanism that activates and breaks the 
conductive link between the electrical energy storage system and the 
rest of the power train. Under these crash conditions in which an 
automatic disconnect mechanism activates, Toyota states that its HFCVs 
would be able to meet the electrical safety requirements of FMVSS No. 
305. However, in low speed crashes where the automatic disconnect 
mechanism is not designed to activate so that the vehicle can be driven 
away after a minor crash (fender-bender), Toyota states that its HFCVs 
would not be able to meet the electrical safety requirements in FMVSS 
No. 305. The petitioner believes that the additional compliance option 
requested in its petition would solve this problem and would not cause 
any reduction in the level of electrical safety now required by FMVSS 
No. 305.
---------------------------------------------------------------------------

    \2\ Subsequent to its submission of the petition for rulemaking, 
Toyota submitted and was granted a temporary exemption from FMVSS 
No. 305 for an HFCV (see grant of petition, January 2, 2015 (80 FR 
101)). Toyota incorporates electrical protection barriers 
(conductively connected to the electric chassis with low resistance) 
and maintains at least a 100 ohms/volt electrical isolation into 
their design. NHTSA granted the petition for exemption on the basis 
that the exemption would make the development or field evaluation of 
a low emission (zero emission) vehicle easier and would not 
unreasonably reduce the safety of the vehicle.
---------------------------------------------------------------------------

    Petitioner Alliance requests a physical barrier compliance option 
to facilitate the production of 48 volt mild hybrid technologies as 
well as hydrogen fuel cell vehicles. The petitioner asks NHTSA to amend 
FMVSS No. 305 to adopt a physical barrier option incorporated in the 
Society of Automotive Engineers (SAE) J1766 Jan 2014,\3\ section 5.3.4, 
for 48 volt mild hybrid systems. The Alliance believes that the 
provisions for physical barriers in section 5.3.4 incorporate the 
requirements of GTR No. 13 and provide for physical barriers that 
ensure equal levels of safety as that afforded by the current FMVSS No. 
305 electrical safety requirements.
---------------------------------------------------------------------------

    \3\ SAE J1766, ``Recommended practice for electric, fuel cell, 
and hybrid electric vehicle crash integrity testing,'' January 2014, 
SAE International, http://www.sae.org.
---------------------------------------------------------------------------

    The petitioner states that while vehicles with 48 volt mild hybrid 
systems use mostly low-voltage components that do not present any 
danger of harmful electric shock, AC voltage sources contained within 
the system can exceed the 30 volt threshold in FMVSS No. 305 for 
consideration as a high voltage source. Since these systems are 
grounded to the vehicle chassis, they cannot meet FMVSS No. 305's 
existing electrical isolation option. The petitioner states that while 
it is feasible to design a 48 volt mild hybrid system that is isolated 
from the chassis and meets FMVSS No. 305's electrical isolation 
requirements, such designs involve more complexity, higher consumer 
costs, and higher mass resulting in reduced fuel economy and increased 
emissions. The petitioner believes that these penalties are 
inappropriate when there would be no incremental safety benefit gained 
beyond that associated with SAE J1766's physical barrier option.
    NHTSA has undertaken this rulemaking after carefully and 
extensively examining the safety issues. The agency previously decided 
against consideration of a physical barrier option earlier in the 
history of FMVSS No. 305, when our knowledge about the option was 
limited.\4\ Commenters to an NPRM to upgrade electrical shock 
protection requirements had asked NHTSA to adopt the option in the 
final rule, for reasons similar to those provided by petitioners Toyota 
and the Alliance. NHTSA declined, citing concerns about the lack of 
notice for the provision, the absence of developed test procedures to 
ensure protection from indirect contact, and uncertainty as to whether 
the option would sufficiently account for indirect contact failure 
modes. NHTSA then decided to undertake a research program (later known 
as the Battelle study, discussed below in this preamble) to better 
understand the issues related to a physical barrier option for 
electrical safety.
---------------------------------------------------------------------------

    \4\ See final rule, 75 FR 33515, June 14, 2010; response to 
petitions for reconsideration, 76 FR 45436, July 29, 2011.
---------------------------------------------------------------------------

    Since that decision in 2010, a number of developments led to 
today's proposal. GTR No. 13 was established, a product of shared data 
and knowledge from governing bodies and international experts around 
the world. The Battelle study was completed and the physical barrier 
countermeasure design was made more robust in response to its findings, 
with SAE revising J1766 in January 2014 to set forth more protective 
safety practices than it had before to address remote albeit lingering 
concerns. Importantly, there have now been years of worldwide 
recognition of the physical barrier option as an acceptable means of 
providing electrical safety in electric powered vehicles, with years of 
experience in design labs and in the field showing no evidence of 
associated safety problems. HFCVs, 48 volt mild hybrid technologies, 
and other vehicle designs have become a reality, and with them abundant 
potential for the development of electrical technologies that a 
physical barrier option in FMVSS No. 305 can facilitate, expedite and 
safeguard.
    We estimate that adopting this NPRM would come at essentially no 
cost to consumers in the U.S. This proposal closely mirrors the 
electrical safety provisions of GTR No. 13, which have been implemented 
by manufacturers in this country.
    NHTSA believes that this NPRM would improve the level of safety 
afforded to the public. Adopting the provisions from GTR No. 13 that 
reduce the risk of harmful electric shock during normal vehicle 
operation would improve FMVSS No. 305 by expanding its performance 
requirements beyond post-crash conditions. The proposed requirements 
would provide post-crash compliance options for new power train 
configurations that ensure that those configurations provide a 
comparable level of post-crash safety compared to existing electric 
vehicles.

Summary of Proposal

    The proposed amendments are summarized as follows. In furtherance 
of implementing GTR No. 13 and in response to the petitions for 
rulemaking--
    a. This NPRM proposes to add electrical safety requirements for 
vehicle performance during everyday (``normal'') vehicle operations (as 
opposed to during and after a crash), to mitigate electric shock due to 
loss in electrical isolation and direct or indirect contact of high 
voltage sources. The electrical safety requirements during normal 
vehicle operations would include requirements for:

    1. Direct contact protection from high voltage sources

    i. IPXXD protection level \5\ for high voltage sources inside 
passenger and luggage compartments. IPXXB protection level for high 
voltage sources not in passenger and luggage compartments.
---------------------------------------------------------------------------

    \5\ IPXXB and IPXXD ``protection levels'' refer to the ability 
of the physical barriers to prevent entrance of a probe into the 
enclosure, to ensure no direct contact with high voltage sources. 
``IPXXB'' is a probe representing a small human finger. ``IPXXD'' is 
a slender wire probe. Protection degrees IPXXD and IPXXB are 
International Electrotechnical Commission specifications for 
protection from direct contact of high voltage sources.
---------------------------------------------------------------------------

    ii. IPXXB protection level for service disconnect that can be 
opened or removed without tools.
    iii. Markings on barriers of high voltage sources that can be 
physically accessed, opened, or removed without the use of tools.

[[Page 12650]]

    iv. Orange color outer covering for cables of high voltage 
sources that are located outside electrical protection barriers.\6\
---------------------------------------------------------------------------

    \6\ An electrical protection barrier is defined in GTR No. 13 as 
the part providing protection from direct contact with high voltage 
sources from any direction of access. These may be physical barriers 
that enclose high voltage sources.

---------------------------------------------------------------------------
    2. Indirect contact protection from high voltage sources

    Exposed conductive parts of electrical protection barriers would 
have to be conductively connected to the chassis with a resistance 
less than 0.1 ohms, and the resistance between two simultaneously 
reachable exposed conductive parts of electrical protection barriers 
that are within 2.5 meters of each other would have to be less than 
0.2 ohms.

    3. Electrical isolation of high voltage sources

    i. 500 ohms/volt or higher electrical isolation for AC high 
voltage sources and 100 ohms/volt or higher for DC high voltage 
sources.
    ii. For conditions where AC and DC bus are connected, AC high 
voltage sources would be permitted to have electrical isolation of 
100 ohms/volt or higher, provided they also have the direct and 
indirect contact protection described in 1 and 2, above.
    iii. There would be an exclusion of 48 volt hybrid vehicles from 
electrical isolation requirements during normal vehicle operation.

    4. Electrical isolation monitoring system for DC high voltage 
sources on fuel cell vehicles.
    5. Electrical safety during charging involving connecting the 
vehicle to an external electric power supply:

    i. Minimum electrical isolation resistance of one million ohm of 
the coupling system for charging the electrical energy storage 
system; and
    ii. Conductive connection of the electric chassis to earth 
ground before and during exterior voltage is applied.

    6. Mitigating driver error by--

    i. Requiring an indication to the driver when the vehicle is in 
active driving mode upon vehicle start up and when the driver is 
leaving the vehicle; and,
    ii. Preventing vehicle movement by its own propulsion system 
when the vehicle charging system is connected to the external 
electric power supply.

    b. This NPRM also proposes to amend FMVSS No. 305's post-crash 
electrical safety requirements. The proposed post-crash electrical 
safety requirements include:

    1. Adding an additional optional method of meeting post-crash 
electrical safety requirements through physical barrier protection 
from high voltage sources. The proposed specifications of this 
optional method of electric safety include requirements ensuring 
that:
    i. High voltage sources would be enclosed in barriers that 
prevent direct human contact with high voltage sources (IPXXB 
protection level),
    ii. Exposed conductive parts of electrical protection barriers 
would be conductively connected to the chassis with a resistance 
less than 0.1 ohms, and the resistance between any two 
simultaneously reachable exposed conductive parts of electrical 
protection barriers that are less than 2.5 meters from each other 
would be less than 0.2 ohms, and
    iii. Voltage between a barrier and other exposed conductive 
parts of the vehicle would be at a low voltage level that would not 
cause electric shock (less than 60 VDC \7\ or 30 VAC).
---------------------------------------------------------------------------

    \7\ VDC is the voltage for direct current sources and VAC is 
voltage for alternating current sources.
---------------------------------------------------------------------------

    2. Permitting an AC high voltage source that is conductively 
connected to a DC high voltage source to meet lower minimum 
electrical isolation requirement of 100 ohms/volt, provided the AC 
high voltage source also has physical barrier protection specified 
in 1, above.

II. FMVSS No. 305

    FMVSS No. 305 currently establishes requirements to reduce deaths 
and injuries during and after a crash that occurs because of 
electrolyte spillage from electric energy storage devices, intrusion of 
electric energy storage/conversion device into the occupant 
compartment, and electrical shock. Among other things, FMVSS No. 305 
requires that during and after the crash tests specified in the 
standard, high voltage sources in the vehicle must be either (a) 
electrically isolated from the vehicle's chassis,\8\ or (b) their 
voltage is below specified levels considered safe from electric shock 
hazards.\9\
---------------------------------------------------------------------------

    \8\ Under this electrical isolation option, since the 
physiological impacts of DC are less than those of AC, the standard 
permits DC high voltage sources with an electrical isolation 
monitoring system to have lower minimum electrical isolation (100 
ohms/volt) than the 500 ohms/volt required for AC high voltage 
sources. This level of electrical isolation limits the current that 
could pass through a human body (that is in contact with the 
vehicle) to no more than 10 milliamperes (mA) DC or 2 mA AC. These 
levels are considered to be safe levels of current and would not 
cause any tissue damage, or fibrillation.
    \9\ Under this low voltage option, electrical components are 
considered to be low voltage and safe from electric shock hazard if 
their voltage is less than or equal to 60 VDC or 30 VAC.
---------------------------------------------------------------------------

    Many of these electrical shock protection requirements were 
established by a June 14, 2010 final rule (75 FR 33515) that revised 
the standard to align it more closely with the April 2005 version of 
SAE J1766. Commenters to the NPRM preceding the June 14, 2010 final 
rule (viz., the Alliance and Global Automakers) requested another 
electrical safety compliance option, called the ``physical barrier 
option,'' for providing greater flexibility to allow introduction of 
advanced power train technologies. In the physical barrier option, high 
voltage sources are enclosed in physical barriers (electrical 
protection barriers) that do not permit entrance of a finger probe into 
the enclosure after the crash test to ensure no direct contact with 
high voltage sources. This option also requires the physical barriers 
to be conductively connected to the electric chassis to ensure no 
electric shock due to indirect contact in the event of loss in 
isolation of a high voltage source.
    In the June 14, 2010 final rule, NHTSA declined to adopt the 
physical barrier option, citing concerns about the sufficiency of 
notice provided for the provision, the absence of developed test 
procedures to ensure protection from indirect contact, and uncertainty 
as to whether the option would sufficiently account for indirect 
contact failure modes. NHTSA stated that it would undertake a research 
program (the Battelle study) to better understand the issues related to 
a physical barrier option for electrical safety.

III. The Global Technical Regulation

a. Overview of the Process

    The United States is a contracting party to the ``1998 Agreement'' 
(the Agreement concerning the Establishing of Global Technical 
Regulations for Wheeled Vehicles, Equipment and Parts which can be 
fitted and/or be used on Wheeled Vehicles). This agreement entered into 
force in 2000 and is administered by the UN Economic Commission for 
Europe's (UN ECE's) World Forum for the Harmonization of Vehicle 
Regulations (WP.29). The purpose of this agreement is to establish 
Global Technical Regulations (GTRs).
    GTR No. 13, ``Hydrogen fuel cell vehicles,'' addresses hydrogen 
fuel cell vehicle technology. NHTSA closely collaborated with experts 
from contracting parties to the 1998 Agreement, particularly Germany 
and Japan, to develop a GTR for hydrogen fueled vehicles that would 
establish levels of safety that are equivalent to or exceeds those for 
conventional gasoline fueled vehicles. The collaborative effort in this 
process led to the establishment of GTR No. 13 in June 2013.
    The U.S. voted on June 27, 2013 in favor of establishing GTR No. 
13. In voting yes to establishing the GTR, NHTSA is obligated to 
``submit the technical Regulation to the process'' used in the U.S. to 
adopt the requirement into our law or regulation. By issuance of this 
NPRM, NHTSA is initiating the process for considering adoption of GTR 
No. 13.

[[Page 12651]]

    Under the terms of the 1998 Agreement, NHTSA is not obligated to 
adopt the GTR after initiating this process. In deciding whether to 
adopt a GTR as an FMVSS, we follow the requirements for NHTSA 
rulemaking, including the Administrative Procedure Act, the National 
Highway and Motor Vehicle Safety Act (Vehicle Safety Act), Presidential 
Executive Orders, and DOT and NHTSA policies, procedures and 
regulations. Among other things, FMVSSs issued under the Vehicle Safety 
Act ``shall be practicable, meet the need for motor vehicle safety, and 
be stated in objective terms.'' 49 U.S.C. 30111.
    This NPRM does not propose the entirety of GTR No. 13 at this time. 
This document only addresses the electrical safety requirements in GTR 
No. 13 (i.e., the electrical isolation requirements, physical barrier 
requirements, etc.). GTR No. 13 also addresses hydrogen fuel system and 
fuel container integrity requirements and the agency's plan is to issue 
a separate proposal to seek comment on incorporating those portions of 
GTR No. 13 into the relevant FMVSSs.

b. Overview of GTR No. 13

    Hydrogen fueled fuel cell vehicles have an electric drive-train 
powered by a fuel cell that generates electric power electrochemically 
using hydrogen. The hydrogen is electrochemically combined with oxygen 
(from air) within the fuel cell system to produce high-voltage electric 
power. The electric power is supplied to the electric drive motors and/
or used to charge batteries and capacitors. HFCVs may also be equipped 
with batteries to supplement the output of fuel cells and may also 
recapture energy during stopping through regenerative braking, which 
recharges batteries and thereby improves efficiency.
    The fuel cell provides DC power while the drive motors typically 
operate on AC. Therefore, the power train has: (a) Inverters to convert 
DC power to AC to run the motors and (b) converters to convert AC power 
generated in the drive motor during regenerative braking to DC to store 
energy in the batteries. In many respects, the electric power train of 
an HFCV is similar to that of electric and hybrid electric vehicles. 
GTR No. 13, in part, specifies electrical safety requirements during 
normal vehicle operation and after a crash test, to protect against 
electric shock in the event of a failure in the high voltage propulsion 
system.
    In general, the portions of GTR No. 13 that are relevant to this 
rulemaking are the electric safety requirements intended to protect 
against the potential for electric shock during (a) normal vehicle 
operation, and (b) after a crash. We discuss these requirements in GTR 
No. 13 in the sections below.
1. Electric Safety Requirements During Normal Vehicle Operation
    These performance requirements in GTR No. 13 are requirements 
intended for protecting vehicle occupants (and others that may interact 
with the vehicle) against electric shock during normal vehicle 
operation.\10\ For the purposes of the GTR, normal vehicle operations 
include those during driving and charging.
---------------------------------------------------------------------------

    \10\ In other words, the focus of this ``in-use'' testing 
(unlike ``post-crash'' testing, discussed later) deals with 
performance criteria that would be assessed without first exposing 
the vehicle to a crash test. This testing is aimed at evaluating 
what the performance of the vehicle would be under normal operating 
conditions.
---------------------------------------------------------------------------

    The GTR requirements apply to all high voltage sources (electric 
components contained or connected to the electric power train that have 
a working voltage greater than 30 VAC or 60 VDC). It requires these 
high voltage sources to have all four of the following measures to 
protect against electric shock during normal vehicle operations: (1) 
Prevent direct contact of high voltage sources (those operating with 
voltage greater than 30 VAC or 60 VDC); (2) prevent indirect contact of 
high voltage sources; (3) electrically isolate the high voltage sources 
from the electric chassis (500 ohms/volt or higher for AC and 100 ohms/
volt or higher for DC sources); and (4) electrical isolation monitoring 
system for HFCVs that warns the driver in the event of loss in 
isolation.
    The GTR also has the following measures to reduce driver errors 
that may result in potential unsafe conditions: (1) Indication to the 
driver when the vehicle is in possible active driving mode at startup 
and when the driver is leaving the vehicle, and (2) prevent vehicle 
movement by its own propulsion system when the vehicle charging system 
is connected to the external electric power supply.
Protection Against Direct Contact With High Voltage Sources
    For protection against direct contact with high voltage sources, 
the GTR has different requirements based on the location of the high 
voltage source (i.e., if it is in the passenger or luggage compartment 
of the vehicle or not).
    The GTR requires high voltage sources inside the passenger 
compartment or luggage compartment to be enclosed in protection systems 
such as solid insulators, electrical protection barriers, and 
enclosures that cannot be opened, disassembled, or removed without the 
use of tools and that provide protection degree IPXXD. Protection 
degree IPXXD is an International Electrotechnical Commission (IEC) 
specification for protection from direct contact of high voltage 
sources. IPXXD protection is verified when a standard probe (rigid test 
wire shown in Figure 1), 100 millimeters (mm) long and 1 millimeter 
(mm) in diameter, does not contact high voltage components when probed 
to enter an electrical protection barrier or enclosure.\11\
---------------------------------------------------------------------------

    \11\ IEC60529 Second edition 1989-11 + Am. 1 1999-11, EN60529, 
``Degrees of protection provided by enclosures.''
[GRAPHIC] [TIFF OMITTED] TP10MR16.000

    For high voltage sources not in passenger or luggage 
compartments,\12\ the GTR requires that they be enclosed in protection 
systems such as solid insulators, electrical protection barriers, and 
enclosures that cannot be opened, disassembled, or removed without the 
use of tools, and that provide a protection degree of IPXXB (as opposed 
to IPXXD, referenced above). Protection degree IPXXB is an IEC 
specification for protection from direct contact of high

[[Page 12652]]

voltage sources. IPXXB protection is verified when a standard probe 
(resembling a small human finger), 80 mm long and 12 mm in diameter, 
does not contact high voltage components when probed to enter an 
electrical protection barrier or enclosure.\13\ (See Figure 2 below.)
---------------------------------------------------------------------------

    \12\ GTR No. 13 specifies direct contact protection requirements 
for high voltage connectors (including vehicle inlet) separately.
    \13\ IEC60529 Second edition 1989-11 + Am. 1 1999-11, EN60529, 
``Degrees of protection provided by enclosures.'' This test probe 
designed to simulate a small human finger (12 mm) conforms to ISO 
20653 ``Road vehicles--Degrees of protection (IP-Code)--Protection 
of electrical equipment against foreign objects, water, and access 
(IPXXB).''
[GRAPHIC] [TIFF OMITTED] TP10MR16.001

    In addition to barriers preventing direct physical contact with 
high voltage sources, GTR No. 13 also requires protections for the 
``service disconnect.'' \14\ These provisions protect emergency 
personnel, persons performing service/maintenance on the vehicle, and 
vehicle occupants. The GTR requires that a service disconnect (which 
can be opened, disassembled or removed without tools) be enclosed by 
protection systems with protection degree IPXXB when the service 
disconnect is opened, disassembled, or removed.
---------------------------------------------------------------------------

    \14\ A service disconnect is a device for deactivation of an 
electrical circuit when conducting checks and services of the 
electric battery, fuel cell stack, or other high voltage sources.
---------------------------------------------------------------------------

    Further, the GTR requires that high voltage sources be labeled 
using the symbol shown in Figure 3, below. The interior of the symbol 
is yellow and the border and arrow symbol are black. This requirement 
aims to provide a standardized warning regarding the presence of high 
voltage sources within an enclosure that can be physically accessed, 
opened or removed without the use of tools. The GTR specifies that the 
labels need to be on or near electric energy storage/conversion devices 
and on electrical protection barriers or enclosures of high voltage 
sources that can be physically accessed, opened, or removed without the 
use of tools and that are not located underneath the vehicle floor. For 
connecters of high voltage sources, the GTR makes this requirement 
optional.
[GRAPHIC] [TIFF OMITTED] TP10MR16.002

    In the same vein, the GTR requires cables to have a standardized 
warning that high voltage cables are present. The GTR requires that 
cables for high voltage sources, which are not located within 
enclosures, must have an orange outer covering for identification.
Protection Against Indirect Contact With High Voltage Sources
    Indirect contact of high voltage sources \15\ may occur when a high 
voltage source experiences a loss in electrical isolation and the 
physical barrier or enclosure gets electrically energized. This type of 
contact could also lead to electrical shock. To address this concern, 
the GTR requires, first, that exposed conductive parts (parts which may 
become electrically energized under electrical isolation failure and 
which can be contacted by a human, such as electrical protection 
barriers and enclosures) be conductively connected to the electrical 
chassis such that the resistance between all exposed conductive parts 
and the electrical chassis is less than 0.1 ohms when there is current 
flow of at least 0.2 amperes (A).\16\ This would ensure that in the 
event of loss in electrical isolation, no dangerous voltage potentials 
are produced between exposed conductive parts and the electrical 
chassis, and therefore very low levels of current would flow through a 
human body contacting different parts of the vehicle.\17\
---------------------------------------------------------------------------

    \15\ Contact of a conductive part which is energized due to loss 
in electrical isolation of a high voltage source is an indirect 
contact of the high voltage source.
    \16\ GTR No. 13 considers this requirement to be met if visual 
inspection indicates that a conductive connection has been 
established by welding. NHTSA has concerns about this provision and 
is requesting comments on it.
    \17\ Since current flows through the path of least resistance, 
most of the current flow would be through the chassis rather than 
through the human body which has a significantly higher resistance.
---------------------------------------------------------------------------

    Second, GTR No. 13 requires that vehicles whose rechargeable energy 
storage systems are charged by conductively connecting to an external 
grounded electric power supply have a device that conductively connects 
the electrical chassis to the earth ground during charging. This 
ensures that if there is a loss in electrical isolation of a high 
voltage source during charging and the vehicle chassis is contacted by 
a human, the magnitude of current

[[Page 12653]]

flowing through the person is very low and in the safe zone.\18\
---------------------------------------------------------------------------

    \18\ Current will flow through the path of least resistance and 
therefore most of the current resulting from a loss of electrical 
isolation would flow through the ground connection rather than 
through the human body.
---------------------------------------------------------------------------

Protection by Electrical Isolation
    GTR No. 13 affords different electrical isolation requirements for 
AC and DC high voltage sources based on whether they are conductively 
isolated from each other or conductively linked together.
    For AC and DC high voltage sources that are conductively isolated 
from each other, GTR No. 13 requires isolation resistance between the 
high voltage source and the electrical chassis to be a minimum value of 
100 ohms/volt of the working voltage for DC high voltage sources, and a 
minimum value of 500 ohms/volt of the working voltage for AC high 
voltage sources. This requirement is similar to the post-crash 
electrical isolation requirement currently in FMVSS No. 305. It ensures 
that in the event high voltage sources are contacted, the current 
flowing through the body is less than or equal to 10 mA DC or 2 mA AC--
which is considered to be safe.\19\
---------------------------------------------------------------------------

    \19\ See IEC TS 60479-1 and TS 60479-2 Effects of Current on 
Human Beings and Livestock--Part 1: General Aspects, 2005-07, 
Reference Nos. CEI/IEC/TS 60479-1:2005.
---------------------------------------------------------------------------

    For AC and DC high voltage sources that are conductively connected, 
GTR No. 13 affords two options. The first option is the vehicle may 
maintain an isolation resistance between the high voltage sources and 
the electrical chassis at no less than 500 ohms/volt of the working 
voltage. The second option is it may provide an isolation resistance 
between the high voltage sources and the electrical chassis of no less 
than 100 ohms/volt of the working voltage and provide physical barrier 
protection for the AC high voltage sources to prevent both direct and 
indirect contact, as discussed above. (Note that a ``physical barrier'' 
approach would be a new concept in FMVSS No. 305.)
    In addition, GTR No. 13 specifies electrical isolation requirements 
for charging electric vehicles whose rechargeable energy storage system 
are charged by conductively connecting to an external power supply. GTR 
No. 13 requires that the isolation resistance between the electrical 
chassis and high voltage sources conductively connected to the vehicle 
inlet which connects to the external power supply to be at least 1 
million (M) ohms when the charge coupler is disconnected. This 
requirement is in accordance with IEC61851-1-2010 \20\ and 
International Standards Organization (ISO) 6469-2 \21\ which prescribe 
electrical isolation for electric vehicles that connect to the power 
grid for charging. A typical minimum allowable isolation requirement 
for a grounded product connected to the power grid is 1000 ohms/volt, 
which computes to 1M ohms.
---------------------------------------------------------------------------

    \20\ IEC 61851-1:2010 Electric vehicle conductive charging 
system--Part 1: General requirements, available at https://webstore.iec.ch/publication/6029.
    \21\ ISO 6469-2:2009 Electrically propelled road vehicles--
Safety specifications--Part 2: Vehicle operational safety means and 
protection against failures. Available at http://www.iso.org/iso/catalogue_detail?csnumber=45478.
---------------------------------------------------------------------------

Protection by Electrical Isolation Monitoring System
    GTR No. 13 also contains provisions for monitoring the electrical 
isolation under certain conditions. In fuel cell vehicles, GTR No. 13 
requires DC high voltage sources (other than the coupling system for 
charging) to have an on-board electrical isolation monitoring system, 
together with a warning to the driver if the isolation resistance drops 
below the minimum required value of 100 ohms/volt. FMVSS No. 305 
specifies a similar requirement except that FMVSS No. 305 applies this 
provision to vehicles that are certified to the 100 ohms/volt 
electrical isolation option \22\ (rather than to fuel cell vehicles 
specifically).
---------------------------------------------------------------------------

    \22\ As discussed above, AC high voltage sources are required 
under FMVSS No. 305 to have at least 500 ohms/volt of electrical 
isolation. DC high voltage sources may have an electrical isolation 
of 100 ohms/volt or greater provided that they meet conditions such 
as having an electrical isolation monitoring system meeting the 
requirements of the standard.
---------------------------------------------------------------------------

Protection by Mitigating Driver Error
    GTR No. 13 also has provisions for mitigating the likelihood of 
driver error in operating electric vehicles. First, GTR No. 13 requires 
that at least a momentary indication be given to the driver when the 
vehicle is in possible active driving mode.\23\ Second, when leaving 
the vehicle, the driver shall be informed by an optical or audible 
signal if the vehicle is still in possible active driving mode. The 
third requirement is that for vehicles where the on-board rechargeable 
energy storage/conversion device can be charged externally, vehicle 
movement by its own propulsion system shall not be possible when the 
external electric power supply is physically connected to the vehicle 
inlet.
---------------------------------------------------------------------------

    \23\ I.e., the vehicle mode when application of pressure to the 
accelerator pedal or release of the brake system causes the electric 
power train to move the vehicle.
---------------------------------------------------------------------------

    The first requirement does not apply to vehicles with an internal 
combustion engine that directly or indirectly provides the vehicle's 
propulsion on startup. Since electric powered vehicles operate quietly, 
an indication of the vehicle in possible active driving mode would 
assist the driver in reducing operational errors that could have safety 
implications. The third requirement prevents the charger from getting 
ripped out of the vehicle inlet during charging that could cause 
electrical arcing.
2. Electric Safety Requirements Post-Crash Test
    The post-crash \24\ electrical safety requirements in GTR No. 13 
apply to all high voltage sources (electric components contained or 
connected to the electric power train that have a working voltage 
greater than 30 VAC or 60 VDC). GTR No. 13 does not specify the type of 
crash test and how it is conducted. This is left to each contracting 
party to develop appropriate crash tests. After the crash test, to 
provide adequate protection against electric shock, GTR No. 13 affords 
three potential options that a vehicle manufacturer may use to protect 
against potential human contact with high voltage sources. GTR No. 13 
specifically gives contracting parties the choice not to provide the 
physical barrier option in their final domestic regulation.
---------------------------------------------------------------------------

    \24\ In terms of ``post-crash'' we are referring to assessing a 
vehicle's electrical safety provisions (electrical isolation, 
physical barrier, etc.) after the vehicle is exposed to specified 
crash forces in a crash test. This is different from the 
aforementioned ``in-use'' (or ``normal operating conditions'') 
requirements where the vehicle is evaluated for conformance with a 
performance requirement without first being exposed to crash 
testing.
---------------------------------------------------------------------------

Reduce the Voltage Levels of the High Voltage Sources Such That They 
Are No Longer High Voltage Sources
    Reducing the high voltage sources' voltage to a level below what is 
considered a ``high voltage source'' means there is no further need to 
protect against electrical shock from those sources. Thus, in this 
option, GTR No. 13 requires that the voltages of each high voltage 
source be reduced to less than or equal to 30 VAC or 60 VDC within 60 
seconds after the impact. A version of this option for electrical 
safety is currently in FMVSS No. 305.
Use a Physical Barrier and Other Techniques To Prevent Direct/Indirect 
Contact \25\ With High Voltage Sources
---------------------------------------------------------------------------

    \25\ To reiterate, this option is one that contracting parties 
may choose not to propose. In other words, a contracting party that 
voted in favor of this GTR may submit this GTR to their domestic 
rulemaking process affording only two options for protecting against 
post-crash electrical shock (i.e., reducing the high voltage 
sources' voltage so that they are no longer considered high voltage; 
and maintaining the required levels of electrical isolation of the 
high voltage sources).
---------------------------------------------------------------------------

    The physical barrier option protects against electrical shock by 
preventing

[[Page 12654]]

any human contact (direct or indirect) with the high voltage sources. 
The physical barrier option for post-crash is similar to the physical 
barrier option that GTR No. 13 affords for its normal vehicle operation 
requirement. The requirements state that (post-crash) the vehicle needs 
to prevent both direct and indirect human contact with high voltage 
sources through the use of: (1) Physical barriers (i.e., prevent a 
finger probe test device from contacting any high voltage source); and 
(2) low resistance conductive connection of the physical barriers to 
the electrical chassis (i.e., the resistance between all exposed 
conductive parts and the electrical chassis has to be less than 0.1 
ohms when there is a current flow of at least 0.2 A \26\). The only 
major difference is that GTR No. 13 uses protection degree IPXXB (i.e., 
the IPXXB finger probe) for its post-crash requirements (rather than 
IPXXD).\27\ As noted earlier, FMVSS No. 305 currently contains no 
similar provision for electric shock protection through physical 
barriers.
---------------------------------------------------------------------------

    \26\ GTR No. 13 considers this requirement to be met if visual 
inspection indicates that conductive connection has been established 
by welding. The minimum resistance requirement is only evaluated in 
case of doubt.
    \27\ Here the post-crash requirements in the GTR use IPXXB 
because it is assumed unlikely that, post-crash, someone would use a 
wire to probe the enclosure.
---------------------------------------------------------------------------

Electrically Isolate the High Voltage Sources
    This option protects against electric shock by ensuring that a 
sufficient level of electrical isolation resistance is provided for the 
high voltage source. GTR No. 13 provides two different sets of 
requirements (based on whether the vehicle's AC and DC high voltage 
sources are conductively connected) for vehicles electing to use this 
option to protect against electric shock.
    If the AC and DC high voltage sources are conductively isolated 
from each other, then the minimum electrical isolation of a high 
voltage source to the chassis is 500 ohms/volt for AC components and 
100 ohms/volt for DC components of the working voltage.
    If AC and DC high voltage sources are conductively connected, GTR 
No. 13 requires that electrical isolation of AC and DC high voltage 
sources be no less than 500 ohms/volt of the working voltage, or the 
electric isolation of those sources be no less than 100 ohms/volt 
provided that the AC high voltage sources (in addition to the minimum 
100 ohms/volt electrical isolation) meet the reduced voltage level 
requirements discussed above (first option), or meet the physical 
protection requirements discussed above in the second option.
    We note that while currently FMVSS No. 305 contains different 
requirements for AC high voltage sources and DC high voltage sources, 
it does not distinguish requirements based on whether the AC and DC 
high voltage sources are conductively linked. Thus, while the 
requirements in GTR No. 13 for AC and DC sources that are not 
conductively connected are the same as those currently in FMVSS No. 
305, the alternative requirements for conductively connected AC and DC 
sources are not.

c. How does this proposal differ from GTR No. 13?

    This NPRM proposes to add electrical safety requirements during 
normal vehicle operation in GTR No. 13 into FMVSS No. 305. The proposal 
also adds a modified version of physical barrier protection that is 
specified in GTR No. 13 as a compliance option for meeting post-crash 
electrical safety requirements. However, this NPRM does not propose to 
adopt all the specifications in GTR No. 13. The differences in 
electrical safety requirements and associated test procedures in the 
proposal and that in GTR No. 13, along with an explanation for these 
differences, are provided below. Comments are requested on NHTSA's 
views.
Physical Barrier Protection During Normal Vehicle Operation
    This NPRM proposes to adopt GTR No. 13's physical barrier 
protection requirement during normal vehicle operation for direct 
contact. However, for indirect contact protection, we propose to use 
the proposed post-crash indirect contact protection requirements 
described above (which include two additional requirements described 
above in addition to that specified in GTR No. 13).
Verification of Physical Barrier Protection During Normal Vehicle 
Operations
    GTR No. 13 considers indirect contact protection requirements 
during normal vehicle operations to be met if a galvanic connection 
\28\ has been established by welding between exposed conductive parts 
and the electrical chassis.
---------------------------------------------------------------------------

    \28\ A galvanic connection is a conductive connection.
---------------------------------------------------------------------------

    For conditions where the DC and AC high voltage sources are 
connected during normal vehicle operations, GTR No. 13 permits the AC 
high voltage sources to have a minimum electrical isolation of 100 
ohms/volt provided the AC high voltage sources have either: (a) Double 
or more layers of solid insulators or electrical protection barriers 
that meet the requirements for indirect contact protection; or (b) 
Mechanically robust protections that have sufficient durability over 
vehicle service life such as motor housings, electronic converter cases 
or connectors.
    These methods of verification consist of mere visual inspection and 
do not provide sufficient objectivity for use in an FMVSS. Therefore, 
the agency's proposal does not consider indirect contact protection 
requirements to be met if galvanic connection has been established 
between exposed conductive parts and the electric chassis. The agency 
is also not proposing visual inspection methods to permit AC high 
voltage sources that are connected to a DC high voltage source to have 
minimum electrical isolation of 100 ohms/volt during normal vehicle 
operation.
High Voltage Markings
    GTR No. 13 requires marking (yellow high voltage symbol) for 
enclosures and barriers of high voltage sources (electrical protection 
barriers) that can be physically accessed, opened, or removed without 
the use of tools. These markings are not required for electrical 
protection barriers located underneath the vehicle floor.
    NHTSA tentatively concludes that the exclusion is without merit. 
GTR No. 13 does not provide a justification for exempting electrical 
protection barriers located underneath the vehicle floor from the high 
voltage marking requirement. There is also no definition of ``vehicle 
floor'' in GTR No. 13. NHTSA does not believe electrical protection 
barriers located under the vehicle floor should be excluded because it 
is possible that the high voltage sources enclosed by these barriers 
may be accessed in a rollover crash or during vehicle maintenance.
Direct Contact Protection of Connectors
    GTR No. 13 specifies direct contact protection requirements for 
high voltage connectors separately. Per GTR No. 13, connectors do not 
need to meet IPXXB protection if they are located underneath the 
vehicle floor and are provided with a locking mechanism, or require the 
use of tools to separate the

[[Page 12655]]

connector, or the voltage reduces to below 30 VAC or 60 VDC within one 
second after the connector is separated. NHTSA does not believe 
connectors of high voltage sources should be excluded. If connectors 
are high voltage sources and if they can be accessed, opened, or 
removed without the use of tools, regardless of whether they are 
located under the floor, they should be required to meet the same 
requirements for voltage markings and direct contact protection as 
electric protection barriers. Additionally, the agency notes that 
``vehicle floor'' and ``connector'' are not defined in GTR No. 13. 
Therefore, NHTSA would not exclude connectors of high voltage sources.
Post-Crash Physical Barrier Protection Option
    GTR No. 13 specifies that individual contracting parties of the 
1998 agreement may elect to propose the physical barrier protection 
from direct and indirect contact of high voltage sources and live 
parts. According to GTR No. 13, for protection against direct contact, 
high voltage sources and live parts are required to have protection 
degree IPXXB. For protection against indirect contact, GTR No. 13 
requires that the resistance between all exposed conductive parts and 
electrical chassis be lower than 0.1 ohm when there is current flow of 
at least 0.2 A.
    The physical barrier protection option in this NPRM includes the 
same provisions for direct and indirect contact protection as that in 
GTR No. 13 but adds two additional requirements for indirect contact 
protection (from SAE J1766 January 2014).
    This first additional requirement is that the resistance between 
any two simultaneously reachable exposed conductive parts of the 
electrical protection barriers that are less than 2.5 meters from each 
other is less than 0.2 ohms. This additional requirement protects 
against indirect contact of high voltage sources when two electrical 
protection barriers are contacted simultaneously. The second additional 
requirement is that the voltages between an electrical protection 
barrier enclosing a high voltage source and other exposed conductive 
parts are less than or equal to 30 VAC or 60 VDC. This additional 
requirement is included in SAE J1766 January 2014 to provide additional 
protection from indirect contact of high voltage sources, addressing 
the issues raised in the Battelle research of the physical barrier 
protection option.
Verification of Post-Crash Indirect Contact Protection
    GTR No. 13 states that a high voltage source is considered to have 
post-crash indirect contact protection if the electrical protection 
barrier enclosing the high voltage source has a galvanic connection to 
the chassis by welding. This method of verification is a mere visual 
inspection and lacks the objectivity needed for an FMVSS. This NPRM 
does not include this method of verification and instead proposes to 
use the test procedure in GTR No. 13 whereby a current of 0.2 A is 
passed through the connection to determine its resistance.
Physical Barrier Protection of AC High Voltage Sources That Are 
Connected to DC High Voltage Sources
    This NPRM proposes to adopt the physical barrier protection 
requirement for direct contact specified in GTR No. 13 for both post-
crash and during normal vehicle operation. However, for indirect 
contact protection, the proposal uses the proposed post-crash indirect 
contact protection requirements described above (which include two 
additional requirements described above in addition to that specified 
in GTR No. 13).
Optional Procedures for Evaluating Electrical Isolation Post-Crash
    FMVSS No. 305's test procedure for measuring electrical isolation 
of high voltage sources is similar to that in GTR No. 13. However, GTR 
No. 13 permits the crash tests to be conducted without energizing the 
electric power train while FMVSS No. 305 does not. In conditions where 
the high voltage sources are not energized during the crash test, GTR 
No. 13 permits measuring electrical isolation resistance of high 
voltage sources by other means, including using a megohmmeter.\29\ Yet, 
GTR No. 13 does not specify a test procedure to measure isolation 
resistance using a megohmmeter.
---------------------------------------------------------------------------

    \29\ A megohmmeter is a specialized ohmmeter that is primarily 
used to determine electrical isolation resistance. This device 
operates by applying a voltage or current to the item being tested. 
Because externally applied voltages or currents can disrupt its 
measurement (and/or cause damage to the instrument) the megohmmer is 
used to test items that are under an inactive and fully de-energized 
state.
---------------------------------------------------------------------------

    NHTSA is not proposing to conduct the crash test without energizing 
the electric power train and so is not permitting the use of the 
megohmmeter. NHTSA stated its position on this matter in final rules 
published on June 14, 2010 (75 FR 33515), July 29, 2011 (76 FR 45436), 
and January 16, 2015 (80 FR 2320). In the January 16, 2015 final rule, 
NHTSA noted that the agency's research on the feasibility of using a 
megohmmeter for measuring electrical isolation presented certain 
technical questions that need to be resolved (i.e., the research showed 
that megohmmeters could accurately measure electrical isolation 
resistance of DC high voltage sources in an inactive state but did not 
consistently do so for AC high voltage sources).
    Additionally, electrical isolation resistance measurement with a 
megohmmeter is only possible when the electrical power train is not 
energized, such as when an inert gas is used in hydrogen containers of 
a fuel cell vehicle. NHTSA will address the issue of the use of inert 
gas in hydrogen containers of fuel cells vehicles when conducting crash 
tests in a future proposal to incorporate into FMVSSs the fuel system 
and fuel container integrity requirements of hydrogen fuel cell 
vehicles in GTR No. 13. The agency will address in that rulemaking the 
use of alternative methods of measuring isolation resistance in 
conditions where the electric power train is not energized in crash 
tests.
Procedures for Measuring Voltage Post-Crash
    FMVSS No. 305 specifies that all post-crash voltage measurements 
for determining voltage and electrical isolation of high voltage 
sources with respect to the electric chassis be made after a minimum of 
5 seconds after the vehicle comes to rest following impact. GTR No. 13 
specifies that for determining post-crash electrical isolation of high 
voltage sources, the voltage measurements be made after a minimum of 5 
seconds after ``impact.'' GTR No. 13 also specifies that for 
determining post-crash voltage (for assessing compliance with the low 
voltage option), the voltage measurements be made after a minimum of 5 
seconds and no later than 60 seconds after impact.
    The agency is not proposing to change the timing of voltage 
measurement post-crash in FMVSS No. 305 to harmonize with GTR No. 13. 
The ``after impact'' interval specified in GTR No. 13 appears less 
objective than FMVSS No. 305's measure and adopting the GTR No. 13 
specified time for post-crash voltage measurement may reduce the 
objectivity of the test. Further, all-in-all we believe this difference 
in the timing of voltage measurement in FMVSS No. 305 and GTR No. 13 is 
minor.

[[Page 12656]]

Miscellaneous Differences Between the Proposed Regulatory Text and GTR 
No. 13
    There is some unnecessary or redundant text in some sections of GTR 
No. 13 that we have not included in this proposal, to make the 
regulatory text more concise. An example of this is in the electrical 
isolation option for post-crash electrical safety, under conditions 
when the AC and DC high voltage sources are connected. GTR No. 13 
specifies that the vehicle meet one of the following requirements: (1) 
Electrical isolation of the DC and AC high voltage sources from the 
chassis be no less than 500 ohm/volt; (2) electrical isolation of the 
DC and AC high voltage sources from the chassis be no less than 100 
ohm/volt and the AC high voltage sources also have physical barrier 
protection; or (3) electrical isolation of the AC and DC high voltage 
sources from the chassis be no less than 100 ohm/volt and the AC high 
voltage source is considered as a low voltage source. We believe that 
the option (3) requirement above is unnecessary, because if the AC high 
voltage source is considered as a low voltage source, it already meets 
the low voltage electrical isolation option. Thus, we determined it is 
not necessary to provide option (3).

IV. Battelle Study and Developments

    NHTSA initiated a research program in 2010, using Battelle as a 
contractor, to better understand the safety implications of using a 
physical barrier to protect against electric shock. The objectives of 
the research were to: (a) Determine failure modes associated with 
electrical protection barriers that could potentially result in 
electric shock to occupants in the vehicle or to rescue workers due to 
direct or indirect contact, (b) evaluate the practicability and 
feasibility of test procedures in what was then a draft version \30\ of 
GTR No. 13 for direct and indirect contact protection.
---------------------------------------------------------------------------

    \30\ The electrical safety requirements in the 2010 draft 
version of GTR No. 13 are the same as those in the GTR No. 13 that 
was established on June 27, 2013. Henceforth, we refer to the draft 
version as the adopted GTR.
---------------------------------------------------------------------------

    As discussed below (and in our supporting technical document) \31\ 
the Battelle research indicates that the physical barrier protection 
specified in GTR No. 13 would protect against electric shock when there 
is a single point failure in the electrical safety systems. However, if 
there were multiple failures in the electrical safety systems specified 
in GTR No. 13 for normal vehicle operating conditions,\32\ the Battelle 
research indicates that a person could receive an electric shock when 
they contact the high voltage sources in certain specific ways.
---------------------------------------------------------------------------

    \31\ Along with this document, we have placed in the docket a 
supporting technical document providing further information on our 
analysis of the Battelle research and GTR No. 13.
    \32\ Under GTR No. 13, during normal vehicle operation, all high 
voltage sources contained or connected to the power train are 
required to be electrically isolated from the chassis (with minimum 
electrical isolation of 500 ohms/VAC or 100 ohms/VDC) and enclosed 
by physical barriers that prevent direct human contact. The physical 
barriers enclosing these high voltage sources are required to be 
conductively connected to the chassis (with resistance less than 0.1 
ohms) to provide indirect contact shock protection.
---------------------------------------------------------------------------

    The Battelle study \33\ identified various scenarios of electrical 
safety system failures, including direct contact of high voltage 
source, indirect contact of live parts of high voltage sources, loss in 
conductive connection between electrical protection barrier and 
chassis, and a combination of these failures. Direct contact of a high 
voltage source could occur in the event of a crash that results in 
mechanical failure of protection barriers or penetration of electrical 
insulation that would allow fingers or conductive tools to enter 
protection barriers and contact the high voltage sources within the 
barrier. Indirect contact of high voltage sources could occur in the 
event of a crash in which an electrical protection barrier is energized 
due to loss in electrical isolation of the high voltage source within 
the barrier.
---------------------------------------------------------------------------

    \33\ Hydrogen Fuel Cell Vehicle--Electrical Protective Barrier 
Option, Final Report, DOT HS 812134, May 2015. Available at http://www.nhtsa.gov/Research/Crashworthiness/Alternative%20Energy%20Vehicle%20Systems%20Safety%20Research and in 
the docket for this NPRM.
---------------------------------------------------------------------------

    To illustrate failure modes associated with electric protection 
barriers, Battelle used the schematic shown in Figure 4 below in which 
a high voltage source (shown on the left side of the figure) is 
isolated from the vehicle chassis by resistances RiH and 
RiL on the positive and negative side, respectively, and 
enclosed in an electrical protection barrier (EPB1). The 
high voltage source may be either DC or AC and may represent a variety 
of components such as a fuel cell, battery, motor, or capacitor.
    Also shown in Figure 4 are electrical wirings from the positive 
side of the high voltage source to its negative side to complete the 
circuit. The schematic shows two electric protection barriers 
(EPB2 and EPB3) enclosing the wirings on the 
positive and negative side, respectively, and a body with resistance 
Rb contacting these two protection barriers. All three 
electrical protection barriers in the figure are conductively connected 
to the electrical chassis with resistances RCh, 
RChH, and RChL.
    For normal vehicle operation, GTR No. 13 requires RiH 
and RiL resistances to provide electrical isolation of at 
least 500 ohms/VAC or 100 ohms/VDC. It also requires the electrical 
wiring to be insulated. Further, it requires the three electrical 
protection barriers (EPB1, EPB2, and 
EPB3) to have protection degree IPXXD or IPXXB and be 
conductively connected to the chassis such that the resistances 
RCh, RChH, and RChL are less than 0.1 
ohms. The lowest possible value of body resistance Rb is 500 
ohms.\34\
---------------------------------------------------------------------------

    \34\ IEC TC-60479-I, ``Effects of current on human beings and 
livestock--Part I--General Aspects,'' 2005.

---------------------------------------------------------------------------

[[Page 12657]]

[GRAPHIC] [TIFF OMITTED] TP10MR16.003

    Battelle's analysis of the schematic in Figure 4 identified 
scenarios of direct contact and indirect contact of high voltage 
sources. Direct contact occurs when the electrical protection barriers 
EPB2 and/or EPB3 are breached or penetrated and 
the body contacts the wiring enclosed within. Indirect contact occurs 
when EPB2 and/or EPB3 are energized due to loss 
of electrical isolation of the high voltage source within the barrier 
and the body contacts the electrical protection barriers as shown in 
Figure 4. Examples of direct and indirect contact scenarios are 
presented below:
     Case 1--Direct contact of high voltage source without 
electric shock hazard. Protection barrier EPB2 is 
compromised and the body directly contacts the electrical wiring from 
the positive side, and also contacts the electrical protection barrier 
EPB3 enclosing the wiring on the negative side of the high 
voltage source (Figure 5). In this case, as long as the resistance 
RiL or RiH is greater than or equal to 500 ohms/
VAC or 100 ohms/VDC, the current through the body (shown by dashed 
lines) will be within safe limits.
[GRAPHIC] [TIFF OMITTED] TP10MR16.004

     Case 2--Direct contact of a high voltage source with 
electric shock hazard. Electrical protection barriers EPB2 
and EPB3 of the wiring on the positive and negative side of 
the high voltage source are compromised and the body contacts the 
positive and negative wiring (Figure 6). For the worst Case 2 
condition, a body resistance Rb equal to 500 ohms (lowest 
possible) is used. For a DC high voltage source of 350V, the minimum 
resistance value for RiL and RiH is 35,000 ohms. 
Since the body resistance Rb is significantly lower than the 
electrical isolation RiL and RiH,

[[Page 12658]]

current through the body (shown by dashed lines) is not limited and the 
body would experience electric shock.
[GRAPHIC] [TIFF OMITTED] TP10MR16.005

     Case 3--Indirect contact of high voltage source without 
electric shock hazard. The wiring on the positive side of the high 
voltage source loses electrical isolation to the electrical protection 
barrier, EPB2, and the body contacts the electrical 
protection barriers EPB2 and EPB3 of the positive 
and negative wiring (Figure 7). Similar to Case 1, as long as the 
isolation resistance RiL or RiH is greater than 
or equal to 500 ohms/VAC or 100 ohms/VDC, the current through the body 
(shown by dashed lines) will be within safe limits.
[GRAPHIC] [TIFF OMITTED] TP10MR16.006

     Case 4--Indirect contact of high voltage source with 
possibility of electric shock. The electric wiring of the positive and 
negative sides of the high voltage source lose electrical isolation to 
the protective barriers EPB2 and EPB3, 
respectively, and the body contacts the two protective barriers 
EPB2 and EPB3 (Figure 8). Since RCh, 
RChH and RChL are all very low values (less than 
0.1 ohms according to GTR No.13), this condition would result in a 
short circuit of the high voltage source that could activate and open a 
short circuit fuse that is generally equipped in electric

[[Page 12659]]

propulsion vehicles. If a fuse activates, then no current will flow and 
so no electrical shock would occur. However, if the fuse does not 
activate, and if the electrical isolation RiL and 
RiH are reduced to low levels and the chassis resistance is 
not significantly low compared to the body resistance, then the current 
through the body contacting the protective barriers (shown by dashed 
line) may not be within safe limits and the body could experience 
electric shock. This scenario is further discussed in the Alliance 
petition for rulemaking (infra) and in the supporting technical 
document of this NPRM.
[GRAPHIC] [TIFF OMITTED] TP10MR16.007

    Battelle identified additional scenarios, including those regarding 
loss in electrical isolation RiL and/or RiH and 
loss of electrical bonding of the protective barriers with the 
chassis.\35\ These scenarios showed that, for vehicles that meet the 
electrical isolation and physical barrier protection requirement in GTR 
No. 13 during normal vehicle operation, electric shock is not possible 
when there is only a single point of failure in the electrical safety 
systems. However, electric shock is possible when at least two or three 
failures of electrical safety systems occur and a human body comes into 
contact with two compromised protective barriers on opposite sides of 
the high voltage source to complete the circuit. For example, in Case 
2, electric shock could occur if two electrical protection barriers on 
the positive and negative side of the high voltage source are 
compromised and a body contacts the positive and negative side of a 
high voltage source by entering the two compromised protection 
barriers. In Case 4, electric shock could occur only if at least four 
electric safety features (loss in electrical isolation of electrical 
protection barriers EPB2 and EPB3 which are on the positive and 
negative side of the high voltage source and loss in electrical 
isolation RiH and RiL of the high voltage source) are compromised and 
the body contacts both compromised barriers, EPB2 and EPB3.
---------------------------------------------------------------------------

    \35\ Details of these scenarios are presented in the Battelle 
final report, DOT HS 812 134, May 2015, which is available in the 
docket of this NPRM.
---------------------------------------------------------------------------

    To address the concern of electric shock from indirect contact, GTR 
No. 13 specifies that the physical barriers enclosing high voltage 
sources should be conductively connected with low resistance (less than 
0.1 ohms) to the electrical chassis, so that if one segment of the high 
voltage source should lose electrical isolation, all contactable 
surfaces of the vehicle chassis and protective barriers will be at the 
same voltage and thereby prevent electric shock to a person touching 
two different protective barriers or parts of the electrical chassis.
    Battelle also evaluated the maximum resistance (0.1 ohms) of the 
electric bonds between electrical protection barriers and the 
electrical chassis that is specified in GTR No. 13. Battelle found that 
in the event of multiple electrical safety system failures (loss in 
electrical isolation of both segments of the high voltage source to 
their electrical protection barriers) and a person touching both the 
barriers to complete the circuit, the resistance of 0.1 ohms between 
the protective barrier and electrical chassis would not be sufficient 
to prevent electric shock to the person contacting the protective 
barriers.\36\
---------------------------------------------------------------------------

    \36\ This issue is further explained in the supporting technical 
document in the docket of this NPRM.
---------------------------------------------------------------------------

V. Toyota Petition for Rulemaking

    On December 23, 2013, Toyota submitted a petition for rulemaking to 
amend FMVSS No. 305 by adding an additional compliance option for 
electrical safety to allow HFCVs to be offered for sale in the US. 
Toyota notes that the requested compliance option includes elements of 
the electrical protection barrier that is currently in GTR No. 13. 
Toyota notes that many countries, including the European Union, Japan, 
and South Korea, already include electrical protection barrier as a 
compliance option for electrical safety in their standards.
    Toyota explains its reasons for petitioning as follows.\37\ FMVSS 
No. 305

[[Page 12660]]

requires compliance with electrical safety requirements following 
impacts ``at any speed up to and including'' the specified test speeds. 
Toyota notes that for electric powered vehicles, including fuel cell 
vehicles, the DC high voltage sources (e.g. high voltage battery) will 
be connected to the AC high voltage sources (e.g. electric motor) 
during normal vehicle operation and in low speed crashes where the 
automatic disconnect does not operate.\38\ In such conditions, when the 
AC and DC high voltage sources are connected, the isolation resistance 
at the AC high voltage source is in parallel with the isolation 
resistance of the DC high voltage source. Therefore, even if the 
electrical isolation provided for the AC high voltage source is 
significantly greater than the required 500 ohms/volt, the effective 
isolation resistance measured at the AC high voltage source can be, at 
most, as high as that provided for the DC high voltage source.
---------------------------------------------------------------------------

    \37\ Honda Motor Co. Ltd. and American Honda Motor Co. Inc. 
(Honda) echoed these concerns in its comments on NHTSA's notice of 
receipt of Toyota's exemption petition, supra. See Docket No. NHTSA-
2014-0068.
    \38\ Toyota noted that the automatic disconnect mechanism is not 
activated in low speed crashes, such as minor fender benders that 
may occur in a parking lot and in conditions where the inverters in 
the fuel cell auxiliary system may continue to operate.
---------------------------------------------------------------------------

    Toyota explains that in current battery electric vehicles, 
manufacturers are able to provide electrical isolation for the high 
voltage battery in excess of 500 ohms/volt, even though FMVSS No. 305 
permits DC high voltage sources to have 100 ohms/volt with an 
electrical isolation monitoring system. On the other hand, it is 
difficult to maintain electrical isolation greater than 500 ohms/volt 
for the fuel cell stack in an HFCV due to the presence of fuel cell 
coolant.\39\ Therefore, when the DC and AC high voltage sources are 
connected in an HFCV, it may not be possible to achieve the required 
500 ohms/volt electrical isolation for AC high voltage sources.
---------------------------------------------------------------------------

    \39\ The fuel cell coolant may get ionized during repeated 
operation and may reduce the electrical isolation provided.
---------------------------------------------------------------------------

    Toyota states that NHTSA said in the June 14, 2010 final rule (75 
FR 33515) that the agency was issuing the final rule to facilitate the 
development and introduction of fuel cell vehicles. One provision 
provided by the final rule was to specify lower minimum electrical 
isolation requirements for DC than AC high voltage sources (500 ohms/
volt for AC and 100 ohms/volt for DC sources). Toyota further asserts 
that this flexibility offered for HFCVs is not useful unless a 
provision is made for the condition when the AC and DC high voltage 
sources are connected, such as after a low speed crash.\40\ Since such 
a provision is currently not available, HFCVs are essentially required 
to provide electrical isolation levels at or in excess of 500 ohms/volt 
at the fuel cell stacks.
---------------------------------------------------------------------------

    \40\ FMVSS No. 305 requires that the electrical safety 
requirements in FMVSS No. 305 be met after front, rear, and side 
crash tests that include low speeds. In such conditions (which 
includes ``fender benders''), the automatic disconnect is designed 
to remain closed so that the vehicle remains operational and so the 
driver can continue driving the vehicle.
---------------------------------------------------------------------------

    Toyota asks that NHTSA adopt an alternative provision for 
electrical safety through isolation of high voltage sources that 
involves electrical protection barriers to address post-crash 
conditions where the AC and DC high voltage sources are connected. The 
petitioner suggests adopting GTR No. 13's specification that the 
electrical isolation of the high voltage source may be greater or equal 
to 100 ohms/volt for an AC high voltage source if that AC source is 
conductively connected to a DC high voltage source, provided that the 
AC high voltage source meets the specified post-crash physical barrier 
protection requirements in GTR No. 13.\41\ The petitioner suggests 
specific regulatory text for the requirements and test procedures that 
are based on the specifications in GTR No. 13 for modifying FMVSS No. 
305 to include the petitioner's requested compliance option.
---------------------------------------------------------------------------

    \41\ The requirements for post-crash physical barrier protection 
option for electrical safety in GTR No. 13 are that after a crash 
test, high voltage sources have protection level IPXXB and that the 
resistance between all exposed conductive parts and the electrical 
chassis be lower than 0.1 ohm when there is a current flow of at 
least 0.2 amperes.
---------------------------------------------------------------------------

    Toyota also requests that NHTSA amend S6.4 of FMVSS No 305 which 
requires vehicles to satisfy all of the post-crash performance 
requirements ``after being rotated on its longitudinal axis to each 
successive increment of 90 degrees . . . . .'' to indicate that 
compliance with electrical isolation and physical barrier protection 
requirements would be evaluated after the vehicle is rotated a full 360 
degrees. Toyota notes that the vehicle conditions related to the 
electrical isolation and physical barrier protection requirements do 
not change at various increments of a rollover and that it would be 
unreasonably dangerous for laboratory personnel to conduct the 
specified tests with the vehicle at 90 degree increments.

VI. Alliance Petition for Rulemaking

    On November 10, 2014, the Alliance submitted a petition for 
rulemaking to update and upgrade FMVSS No. 305 to incorporate a 
physical barrier compliance option to provide protection against 
electric shock. The Alliance states that the implementation of a 
physical barrier compliance option is especially critical to facilitate 
both the introduction of complying HFCVs as well as 48 volt mild hybrid 
technologies.\42\ The petitioner also believes the amendments would 
enable safe design innovation for all electrified vehicles, as well as 
reduce CO2 emissions and increase fuel economy.
---------------------------------------------------------------------------

    \42\ 48 volt mild hybrid systems are generally internal 
combustion engines and a 48 volt battery equipped with an electric 
machine (one motor/generator in a parallel configuration) allowing 
the engine to be turned off whenever the car is coasting, braking, 
or stopped, yet restart quickly. These mild hybrids may employ 
regenerative braking and some level of power assist to the internal 
combustion engine, but do not have an exclusive electric-only mode 
of propulsion.
---------------------------------------------------------------------------

    The Alliance states that the physical barrier compliance option is 
essential for FMVSS No. 305 certification of HFCVs in low speed crashes 
where the automatic disconnect is not designed to operate. The Alliance 
also states that in such crashes, the DC high voltage source can 
impinge on the AC high voltage sources through the inverter, making it 
impractical to achieve 500 ohms/volt electrical isolation for the AC 
high voltage source.
    The Alliance explains that while it would seem that 48 volt mild 
hybrid systems would not be within the intended scope of FMVSS No. 
305,\43\ these systems typically convert DC voltage into three-phase AC 
voltage that can exceed the 30 VAC voltage threshold for consideration 
as a high voltage source in FMVSS No. 305.\44\ The

[[Page 12661]]

Alliance states that these 48 volt mild hybrid systems are grounded to 
the vehicle chassis and so cannot viably meet the existing isolation 
resistance option as well as the pretest measurement for isolation 
resistance. The Alliance notes that while it is feasible to design a 48 
volt mild hybrid system that meets FMVSS No. 305 electrical isolation 
requirements, isolated systems inherently involve more complexity, 
higher consumer costs, and higher mass resulting in reduced fuel 
economy and increased emissions. The Alliance suggests that these 
results are particularly inappropriate since there is no incremental 
safety benefit provided by an isolated system compared to physical 
barriers. The Alliance states that as a result, it is requesting 
modifications to FMVSS No. 305 to permit the introduction 48 volt mild 
hybrid systems and HFCVs into the U.S.
---------------------------------------------------------------------------

    \43\ FMVSS No. 305 considers electrical sources operating at 
voltages greater than or equal to 30 VAC or 60 VDC as high voltage 
sources that are subject to FMVSS No. 305 electrical safety 
requirements.
    \44\ We have also considered information provided by Mercedes-
Benz in a briefing to the agency on June 2, 2015. As explained by 
Mercedes-Benz, the AC-DC inverter converts the DC current from the 
48 V battery into AC for the 3-phase AC motor. Mercedes-Benz showed 
that the voltage between the electrical chassis and each of the 
phases of the AC electric motor is switched DC voltage (voltage 
between 0 and 48 volts). Since that voltage is less than 60 volts, 
it is considered low DC voltage under FMVSS No. 305. However, 
Mercedes-Benz noted that the voltage between two phases of the AC 
motor is AC, and may be slightly greater than 30 VAC under certain 
circumstances, which can be considered a high voltage AC source 
under the standard. Mercedez-Benz explained its view that physical 
barrier protection around the AC motor, and around cables from the 
inverter to the motor, would mitigate human contact with these AC 
high voltage sources, and thereby mitigate the likelihood of 
electric shock. Additionally, the presenter showed that electrical 
protection barriers enclosing the AC high voltage sources could be 
conductively connected to the chassis with resistance less than 0.1 
ohms, and thereby provide electric shock protection from indirect 
contact of the high voltage sources. See the memorandum in the 
docket for this NPRM on Mercedes-Benz, Daimler AG, input on 48 V 
mild hybrid systems.
---------------------------------------------------------------------------

    The Alliance notes that in NHTSA's July 29, 2011, response to 
petitions for reconsideration of the 2010 final rule,\45\ NHTSA 
deferred consideration of the physical barrier protection option 
pending additional research. The Alliance states that the agency's 
research on the physical barrier option \46\ showed that electric shock 
from indirect contact in a crash could only be possible, if the 
following conditions were met (see Case 4 described above and 
illustrated in Figure 8):
---------------------------------------------------------------------------

    \45\ 76 FR 45436.
    \46\ ``Hydrogen Fuel Cell Vehicle--Electrical Protective Barrier 
Option,'' DOT HS 812134, May 2015, is available at http://www.nhtsa.gov/Research/Crashworthiness/Alternative%20Energy%20Vehicle%20Systems%20Safety%20Research and in 
the docket for this NPRM.
---------------------------------------------------------------------------

    (1) A loss of electrical isolation within the enclosure of a high 
voltage source,
    (2) a loss of electrical isolation within a second (different) high 
voltage source enclosure,
    (3) these two distinct losses in isolation (specified in (1) and 
(2)) occur on opposite rails (positive and negative) of the high 
voltage source,
    (4) the overcurrent devices do not automatically open the circuit 
as a result of the simultaneous loss of isolation on the positive and 
negative rails to ground (the Alliance states that the normal design 
practice is for the overcurrent devices to automatically open under the 
circumstances outlined in (3)),
    (5) a person has access to these two enclosures in the crashed 
vehicle, and
    (6) a person touches these two enclosures simultaneously.
    The Alliance believes that the likelihood of each of the above 6 
events occurring is remote and that the simultaneous occurrence of 
these events in real world situations is even more remote and 
exceedingly small. The Alliance believes that the other scenarios 
identified in the Battelle final report as having potential safety 
concerns similarly require multiple failures in the system to occur, 
followed by what the petitioner believes to be unlikely human contacts 
and a lack of fuses or other electrical safety protection. 
Nevertheless, the Alliance states that, despite the extremely low 
likelihood of a safety issue from any of the scenarios in the final 
Battelle report, the updated version of SAE J1766 (January 2014) \47\ 
includes performance requirements that safeguard against all safety 
critical scenarios identified in the Battelle report.
---------------------------------------------------------------------------

    \47\ SAE J1766, ``Recommended practice for electric, fuel cell, 
and hybrid electric vehicle crash integrity testing,'' January 2014, 
SAE International, http://www.sae.org.
---------------------------------------------------------------------------

    The Alliance expresses its support of the December 23, 2013 
petition for rulemaking from Toyota to modify FMVSS No. 305 to 
facilitate the sale of HFCVs in the U.S. (petition discussed infra) and 
notes that the January 2014 version of SAE J1766 also includes 
provisions for a modified isolation requirement for AC systems with 
physical barriers, as Toyota requests in its petition for rulemaking. 
The Alliance states that SAE J1766 January 2014 also has provisions for 
a ``stand-alone'' physical barrier protection compliance option that is 
needed for facilitating the development of 48 volt mild hybrid systems, 
since electrical components of these systems are conductively connected 
to the chassis and so cannot viably satisfy electrical isolation 
requirements. The Alliance believes that this ``stand-alone'' physical 
barrier compliance option provides sufficient protection to address 
potential (although unlikely, states the petitioner) safety critical 
scenarios identified in the Battelle report.
    The Alliance asserts that while FMVSS No. 305 only evaluates 
electrical safety in post-crash condition, auto manufacturers also 
design for high voltage safety under normal operating conditions. The 
petitioner states that providing physical barriers is the most common 
method of protection against high voltage contact in the automotive 
industry, as well as other industries that use high voltage electric 
circuits. The Alliance believes it is reasonable that this method of 
protection against electric shock hazard can also be used for post-
crash shock protection provided these physical barriers remain intact 
post-crash, and that either the voltage between exposed conductive 
parts is below 30 VAC or 60 VDC, or resistance between exposed 
conductive parts of the barriers and electrical chassis is below 
specified resistance levels.
    The Alliance states it is urgent to update FMVSS No. 305 to 
facilitate the introduction of HFCVs and 48 volt mild hybrid technology 
vehicles that are necessary to accommodate compliance with Corporate 
Average Fuel Economy (CAFE) standards. Consequentially, the petitioner 
states that it is not additionally requesting adoption of the low 
energy compliance option that is also included in SAE J1766 January 
2014. Instead the petitioner requests that the low energy compliance 
option be considered for the electric vehicle safety (EVS) GTR that is 
currently in process.
    SAE J1766 January 2014 also changes the time criterion for 
initiating verification of post-crash electrical safety from 5 seconds 
after the vehicle comes to rest (similar to the specification currently 
in FMVSS No. 305) to 10 seconds after initial impact. The Alliance 
states that given the urgency necessary to facilitate the introduction 
of HFCVs and 48 volt mild hybrid technology, it is limiting its 
petition for rulemaking to only include the post-crash physical barrier 
protection compliance option in SAE J1766 January 2014 into FMVSS No. 
305.
    Specifically, the Alliance requests including section 5.3.4 of SAE 
J1766 January 2014 into FMVSS No. 305. This section provides two 
options for post-crash electrical safety by means of physical barriers.
    The first option (Option 1 for physical barrier protection) is 
similar to the post-crash physical barrier protection option for 
electrical safety in GTR No. 13,\48\ but includes an additional 
requirement that the resistance between the high voltage source 
enclosed by the physical barrier and the exposed conductive parts of 
the electrical protection barrier be greater than 0.01 ohms/volt for DC 
high voltage sources and 0.05 ohms/volt for AC high voltage sources.
---------------------------------------------------------------------------

    \48\ Protection against direct contact with high voltage sources 
is provided by protection degree IPXXB and protection against 
indirect contact of high voltage sources is provided by requiring 
the resistance between exposed conductive parts and the electrical 
chassis to be lower than 0.1 ohm when there is a current flow of at 
least 0.2 amperes.
---------------------------------------------------------------------------

    The second option for electrical safety through electrical 
protection barriers (Option 2 for physical barrier protection) in SAE 
J1776 January 2014

[[Page 12662]]

is through protection from direct contact by protection degree IPXXB, 
and that the voltage between the electrical protection barrier and 
other exposed conductive parts and the electrical chassis is less than 
or equal to 30 VAC for AC high voltage sources and 60 VDC for DC high 
voltage sources. The Alliance states that Option 2 is similar to the 
low voltage option already in FMVSS No. 305.
    The Alliance supplemented its petition by a submission dated 
October 20, 2015, which provided an analysis of its proposal for 
electrical safety through physical barriers.\49\ Figure 9, below, 
presents the circuit diagram the petitioner provided for the 
representation of a high voltage source (e.g., battery) with voltage of 
1,000 VAC or 1,500 VDC, enclosed in physical barriers that are 
conductively connected to the electrical chassis with resistance less 
than or equal to 0.1 ohms. The circuit diagram also has a 
representation of a human body with a minimum resistance of 500 ohms 
\50\ contacting protective barriers enclosing opposite rails of the 
high voltage source. The resistances R1 and R2 in 
Figure 9 represent the resistance between the high voltage source and 
the protective physical barriers that enclose it. This circuit diagram 
is a representation of the indirect contact Battelle scenario, Case 4, 
in the event that electrical isolation of the high voltage source to 
the chassis is lost and RiH and RiL are equal to 
zero.
---------------------------------------------------------------------------

    \49\ The Alliance analysis of the physical barrier protection 
option proposed for electrical safety (October 2014) is in the 
docket of this NPRM.
    \50\ According to IEC TC-60479-I, ``Effects of current on human 
beings and livestock--Part I--General Aspects,'' 2005, the lowest 
possible electrical resistance of a human body is 500 ohms.
[GRAPHIC] [TIFF OMITTED] TP10MR16.008

    According to Option 1 of the electrical protection barrier in the 
Alliance submission, the combined resistance \51\ of R1 and R2 is 
required to be less than or equal to 0.05 ohms/VAC or 0.01 ohms/VDC. 
Under Option 2, the voltage difference between barrier #1 and barrier 
#2 is required to be less than or equal to 30 VAC or 60 VDC. The 
Alliance observes that its analysis using the model in Figure 9 
demonstrates that the proposed physical barrier protection option 
provides equivalent levels of safety as the electrical isolation option 
\52\ currently in FMVSS No. 305 in all the safety critical scenarios 
identified in the Battelle study, including the scenario Case 4 for 
indirect contact.
---------------------------------------------------------------------------

    \51\ R1 and R2 resistances are in a parallel configuration.
    \52\ The current through the body Ib (shown in Figure 9) is less 
than or equal to 10 mA of direct current or 2 mA of alternating 
current.
---------------------------------------------------------------------------

    The Alliance also states that the Option 1 electrical protection 
barrier is the same as that of Option 2 since the conditions that meet 
the Option 1 requirements also meet the Option 2 requirements. The 
Alliance acknowledges that it is difficult to measure the resistance 
between a high voltage source and the exposed conductive parts of the 
electrical protection barrier that encloses the high voltage source, as 
is needed to evaluate the Option 1 electrical protection barrier.\53\ 
The Alliance recommends that NHTSA incorporate Option 2 (direct contact 
protection degree IPXXB and voltage between electrical protection 
barrier and exposed conductive parts less than or equal to 30 VAC or 60 
VDC) into FMVSS No. 305 since its analysis indicates that compliance 
with Option 1 would also entail compliance with Option 2.
---------------------------------------------------------------------------

    \53\ The resistance level is too low to measure accurately and 
in order to access a high voltage source enclosed in the physical 
barrier, some disassembly of the barrier may be required in some 
cases.
---------------------------------------------------------------------------

    The Alliance specifies the following test procedures from Appendix 
C in SAE J1766 January 2014: (1) Section C.1 for verifying IPXXB 
protection degree of physical barriers, which is similar to the 
procedure in GTR No. 13, (2) Section C.2.1 for verifying that the 
resistance between electrical protection barriers and electrical 
chassis is less than 0.1

[[Page 12663]]

ohms, and (3) Section C.2.3 to verify that the voltage difference 
between any two exposed conductive parts of the electric chassis 
(including physical barriers) is less than or equal to 30 VAC or 60 
VDC. The Alliance also specifies Section C.2.2 in SAE J1766 January 
2014 for verifying that the resistance between a high voltage source 
and the electrical chassis \54\ is greater than or equal to 0.05 ohms/
VAC or 0.01 ohms/VDC. We note, however, that section C.2.2 does not 
provide a specific method of measurement and instead states, ``The 
measurement may be performed by any means that provides sufficient 
accuracy for the post-crash situation.''
---------------------------------------------------------------------------

    \54\ Since the resistance between a protective physical barrier 
and the electrical chassis is required to be less than or equal to 
0.1 ohm (a very low value), the resistance between a high voltage 
source and the physical barrier would be the same as or only 
slightly lower than the resistance between the high voltage source 
and the electrical chassis.
---------------------------------------------------------------------------

    These test procedures are further discussed in a later section 
analyzing the petitions for rulemaking to modify FMVSS No. 305.

VII. Overview of Proposed Rule

    NHTSA is initiating rulemaking to consider adopting GTR No. 13 into 
FMVSS No. 305, as appropriate under the Vehicle Safety Act, and to 
address the issues raised by the Alliance and Toyota in their 
respective petitions. We request comment on the decisions put forth in 
this NPRM, including those regarding minor additional provisions that 
the agency is considering to address the concerns of the petitioners.
    NHTSA believes that this NPRM would improve the level of safety 
afforded to the public. Adopting the provisions from GTR No. 13 that 
reduce the risk of harmful electric shock during normal vehicle 
operation would improve FMVSS No. 305 by expanding its performance 
requirements beyond post-crash conditions. The proposed requirements 
would provide post-crash compliance options for new power train 
configurations that ensure that those configurations provide a 
comparable level of post-crash safety compared to existing electric 
vehicles.
    The proposed amendments are summarized as follows. In furtherance 
of implementing GTR No. 13 and in response to the petitions for 
rulemaking--
    a. This NPRM proposes to add electrical safety requirements for 
vehicle performance during normal vehicle operations (as opposed to 
during and after a crash), to mitigate electric shock due to loss in 
electrical isolation and direct or indirect contact of high voltage 
sources. The electrical safety requirements during normal vehicle 
operations would include requirements for:

1. Direct Contact Protection From High Voltage Sources

    i. IPXXD protection level for high voltage sources inside 
passenger and luggage compartments. IPXXB protection level for high 
voltage sources not in passenger and luggage compartments.
    ii. IPXXB protection level for service disconnect that can be 
opened or removed without tools.
    iii. Markings on barriers of high voltage sources that can be 
physically accessed, opened, or removed without the use of tools.
    iv. Orange color outer covering for cables of high voltage 
sources that are located outside electrical protection barriers.

2. Indirect Contact Protection From High Voltage Sources

    Exposed conductive parts of electrical protection barriers would 
have to be conductively connected to the chassis with a resistance 
less than 0.1 ohms, and the resistance between two simultaneously 
reachable exposed conductive parts of electrical protection barriers 
that are within 2.5 meters of each other would have to be less than 
0.2 ohms.

3. Electrical Isolation of High Voltage Sources

    i. 500 ohms/volt or higher electrical isolation for AC high 
voltage sources and 100 ohms/volt or higher for DC high voltage 
sources
    ii. For conditions where AC and DC bus are connected, AC high 
voltage sources would be permitted to have electrical isolation of 
100 ohms/volt or higher, provided they also have the direct and 
indirect contact protection described in 1 and 2, above.
    iii. There would be an exclusion of 48 volt hybrid vehicles from 
electrical isolation requirements during normal vehicle operation.

4. Electrical Isolation Monitoring System for DC High Voltage Sources 
on Fuel Cell Vehicles

5. Electrical Safety During Charging Involving Connecting the Vehicle 
to an External Electric Power Supply

    i. Minimum electrical isolation resistance of one million ohms 
of the coupling system for charging the electrical energy storage 
system; and
    ii. Conductive connection of the electric chassis to earth 
ground before and during exterior voltage is applied.

6. Mitigating Driver Error by--

    i. Requiring an indication to the driver when the vehicle is in 
active driving mode upon vehicle start up and when the driver is 
leaving the vehicle; and,
    ii. Preventing vehicle movement by its own propulsion system 
when the vehicle charging system is connected to the external 
electric power supply.
    b. This NPRM proposes to amend FMVSS No. 305's post-crash 
electrical safety requirements. The post-crash electrical safety 
requirements would include:

    1. Adding an additional optional method of meeting post-crash 
electrical safety requirements through physical barrier protection 
from high voltage sources. The proposed specifications of this 
optional method of electric safety include requirements ensuring 
that:
    i. High voltage sources would be enclosed in barriers that 
prevent direct human contact with high voltage sources (IPXXB 
protection level),
    ii. Exposed conductive parts of electrical protection barriers 
would be conductively connected to the chassis with a resistance 
less than 0.1 ohms, and the resistance between two simultaneously 
reachable exposed conductive parts of electrical protection barriers 
that are less than 2.5 meters from each other would be less than 0.2 
ohms, and
    iii. Voltage between a barrier and other exposed conductive 
parts of the vehicle would be at a low voltage level that would not 
cause electric shock (less than 60 VDC or 30 VAC).
    2. Permitting an AC high voltage source that is conductively 
connected to a DC high voltage source to meet lower minimum 
electrical isolation requirement of 100 ohms/volt provided the AC 
high voltage source also has physical barrier protection specified 
in 1, above.

VIII. Proposal Addressing Safety During Normal Vehicle Operations

    We first discuss the proposed requirements for vehicle performance 
during normal vehicle operations, followed by those for performance 
post-crash.

a. Direct Contact Protection From High Voltage Sources

    GTR No. 13 specifies safety measures to ensure that high voltage 
sources cannot be contacted. This safety measure is to enclose high 
voltage sources in physical barriers (electrical protection barriers) 
to prevent direct human contact. NHTSA is proposing to include in FMVSS 
No. 305 the direct contact protection requirements specified in GTR No. 
13 for the passenger and luggage compartments and other areas.\55\
---------------------------------------------------------------------------

    \55\ GTR No. 13 assesses the potential for direct contact with 
high voltage components using test probes specified in ISO 20653.
---------------------------------------------------------------------------

    NHTSA is proposing to assess protection against direct contact with 
high voltage sources contained inside the passenger and luggage 
compartments using a 1.0 mm diameter and 100 mm long test wire probe 
(IPXXD). This test probe ensures that any gaps in the protective 
barriers are

[[Page 12664]]

no larger than 1 mm and that any live components contained within are 
no closer to the gap than 100 mm. This ensures that body parts, 
miscellaneous tools or other slender conductive items typically present 
in a passenger or luggage compartment cannot penetrate any gaps/seams 
in the protective enclosures and contact high voltage components 
contained within.
    For assessing protection against direct contact with high voltage 
sources in areas other than the passenger and luggage compartments 
under normal operating conditions, NHTSA is proposing to use the test 
probe IPXXB, representing a test finger. In areas other than the 
passenger and luggage compartments, the barrier would not likely 
contact tools and other slender conductive items. Therefore, protection 
using the test wire probe IPXXD would not be necessary and the test 
finger probe IPXXB would be appropriate to prevent inadvertent contact 
with high voltage components contained in the protective enclosures, by 
persons such as mechanics.
    GTR No 13 also requires that a service disconnect that can be 
opened, disassembled, or removed without tools requires IPXXB 
protection when it is opened, disassembled, or removed. NHTSA is 
proposing to include this requirement into FMVSS No. 305, as well as a 
definition for a service disconnect.
    NHTSA is proposing marking (yellow high voltage symbol) for 
enclosures and barriers of high voltage sources that can be physically 
accessed, opened, or removed without the use of tools, similar to GTR 
No. 13. As explained earlier in this preamble, we are not excluding 
some barriers as GTR No. 13 does.
    NHTSA is proposing that cables for high voltage sources which are 
not located within electrical protection barriers to be identified by 
an orange color outer covering, similar to GTR No. 13. However, as 
explained earlier in this preamble, we are not excluding some 
connectors as GTR No. 13 does.
    As noted earlier in this preamble, GTR No. 13 specifies direct 
contact protection requirements for high voltage connectors separately, 
and has exclusions with which we do not agree. Per GTR No. 13, 
connectors do not need to meet IPXXB protection if they are located 
underneath the vehicle floor and are provided with a locking mechanism, 
or require the use of tools to separate the connector, or the voltage 
reduces to below 30 VAC or 60 VDC within one second after the connector 
is separated. For the reasons given earlier, NHTSA does not believe 
that the exclusions are warranted and does not anticipate adopting them 
in a final rule.

b. Indirect Contact Protection From High Voltage Sources

    Under GTR No. 13, exposed conductive parts (parts that can be 
contacted with the test probes, IPXXD or IPXXB, and become electrically 
energized under electrical isolation failure conditions) have to be 
protected against indirect contact during normal vehicle operation. GTR 
No. 13 requires electrical protection barriers or enclosures of high 
voltage sources to be conductively connected to the electrical chassis 
with resistance of no more than 0.1 ohms during normal vehicle 
operations. This requirement would provide protection from electric 
shock by shunting \56\ any harmful electrical currents to the vehicle 
chassis should any electrically charged components lose isolation 
within the protective barrier.
---------------------------------------------------------------------------

    \56\ Shunting is when a low-resistance connection between two 
points in an electric circuit forms an alternative path for a 
portion of the current. If a human body contacts an electrical 
protection barrier that is energized due to loss in electrical 
isolation of a high voltage source enclosed in the barrier, most of 
the current would flow through the chassis rather than through the 
human body because the current path through the chassis has 
significantly lower resistance (less than 0.1 ohm) than the 
resistance of the human body (greater or equal to 500 ohm).
---------------------------------------------------------------------------

    For indirect contact protection, we propose to apply the same 
indirect contact protection requirements and test procedures as would 
apply under post-crash conditions (see discussion in next section, 
below). The proposed indirect contact protection requirements would be 
for exposed conductive parts of electrical protection barriers to be 
conductively connected to the chassis with a resistance less than 0.1 
ohms and that the resistance between two simultaneously reachable 
exposed conductive parts of electrical protection barriers that are 
within 2.5 meters of each other be less than 0.2 ohms. These 
resistances would be measured by passing a current of at least 0.2 A 
between exposed conductive parts and the electrical chassis. For the 
reasons previously discussed, NHTSA is not including GTR No. 13's 
provision that permits visual inspection of welds as a method of 
assessing compliance of indirect contact protection.

c. Electrical Isolation of High Voltage Sources

    This NPRM would require that under normal operating conditions, all 
high voltage sources of the power train and those connected to the 
power train have sufficient electrical isolation resistance measured 
against the electrical chassis to ensure that current flowing through a 
human body in contact with the vehicle is not dangerous.
    For conditions where DC and AC high voltage sources are isolated 
from each other, DC high voltage sources would be required to have a 
minimum electrical isolation of 100 ohms/volt and AC high voltage 
sources would be required to have a minimum of 500 ohms/volt.
    For conditions where DC and AC high voltage sources are connected, 
AC and DC high voltage sources would be permitted to have a minimum 
electrical isolation of 100 ohms/volt, provided the AC high voltage 
source has direct and indirect contact protection in a. and b. above.
    We proposed to exclude 48 volt hybrid vehicles from these 
electrical isolation requirements during normal vehicle operation. 
Since electric components in 48 volt mild hybrid systems are 
conductively connected to the electric chassis, these systems would not 
be able to comply with electrical isolation requirements both during 
normal vehicle operations and after a crash. Therefore, we believe that 
the ``normal use'' requirements in GTR No. 13 need to be modified to 
permit the introduction of 48 volt mild hybrid systems.
    The United Nations Economic Commission for Europe Regulation 100 
(ECE R.100) \57\ normal operation requirements were modified on June 
10, 2014 to facilitate the development and sale of 48 volt mild hybrid 
systems. Under these changes, 48 volt mild hybrid systems that are 
conductively connected to the electrical chassis are exempt from the 
in-use electrical isolation requirements. However, electrical 
protection barriers are still required during normal vehicle operations 
for high voltage components of these 48 volt mild hybrid systems so as 
to provide direct and indirect contact protection. As discussed in a 
later section for post-crash electrical safety requirements, we believe 
that these 48 volt mild hybrid systems with electrical protection 
barriers for all high voltage components in the system would not pose 
concerns regarding electric shock. Therefore, NHTSA proposes to include 
a similar exclusion from in-use electrical isolation requirements for 
48 volt mild hybrid systems that are conductively connected to the 
electrical chassis.
---------------------------------------------------------------------------

    \57\ Uniform Provisions Concerning the Approval of Vehicles with 
Regard to Specific Requirements for the Electric Power Train, ECE 
R.100-02, June 24, 2014.

---------------------------------------------------------------------------

[[Page 12665]]

d. Electrical Isolation Monitoring System for DC High Voltage Sources 
on Fuel Cell Vehicles

    GTR No. 13 requires that DC high voltage sources (other than the 
coupling system for charging) in HFCVs have an on-board electrical 
isolation monitoring system, together with a warning to the driver if 
the isolation resistance drops below the minimum required value of 100 
ohms/volt. Similarly, FMVSS No. 305 currently specifies that DC high 
voltage sources that comply with electrical safety requirements by the 
electrical isolation of 100 ohms/volt must have an electrical isolation 
monitoring system to warn the driver. SiCnce most HFCVs would comply 
with the electrical isolation requirements in FMVSS No. 305 using the 
100 ohms/volt option,\58\ these HFCVs, which must have an electrical 
isolation monitoring system under GTR No. 13, would also be required by 
FMVSS No. 305 to have the monitoring system.
---------------------------------------------------------------------------

    \58\ In fuel cell vehicles, the presence of fuel cell coolant 
may not permit electrical isolation levels of 500 ohms/volt of the 
DC source.
---------------------------------------------------------------------------

    Nonetheless, to ensure that the intent of GTR No. 13 and FMVSS No. 
305 are met, the agency is proposing to amend FMVSS No. 305 to indicate 
expressly that each DC high voltage source in fuel cell vehicles would 
need to be equipped with an electrical isolation monitoring system.

e. Protection From Electric Shock During Charging

    GTR No. 13 requires electric vehicles whose rechargeable energy 
storage system are charged by conductively connecting to an external 
power supply to have a device to enable conductive connection of the 
electrical chassis to the earth ground during charging. Additionally, 
GTR No. 13 requires the isolation resistance between the high voltage 
source and the electrical chassis to be at least 1 million ohms when 
the charge coupler is disconnected. The first requirement ensures that 
in the event of electrical isolation loss during charging, a person 
contacting the vehicle does not form a ground loop with the chassis and 
sustain significant electric shock. The second requirement ensures that 
the magnitude of current through a human body when a person contacts a 
vehicle undergoing charging is low and in the safe zone. NHTSA believes 
these two normal use charging safety requirements are warranted and 
proposes to include them in FMVSS No. 305.

f. Mitigating Driver Error

    Consistent with GTR No. 13, we propose amending FMVSS No. 305 to 
add requirements that mitigate the likelihood of driver error in 
operating electric vehicles. First, we propose requiring vehicles to 
provide an indication to the driver when the vehicle is in an active 
driving mode upon vehicle start up and when the driver is leaving the 
vehicle.\59\ Second, we propose requiring vehicles to prevent vehicle 
movement by its own propulsion system when the vehicle charging system 
is connected to the external electric power supply.
---------------------------------------------------------------------------

    \59\ We note that an NPRM issued on FMVSS No. 114, ``Theft 
protection and rollaway prevention'' (76 FR 77183) proposes to 
require vehicles with keyless ignition controls to provide an 
audible warning to the driver exiting the vehicle while the 
propulsion system is operating. We request comment on whether the 
FMVSS No. 114 requirement, if adopted, would satisfy this provision 
in the GTR.
---------------------------------------------------------------------------

IX. Proposal Addressing Safety Post-Crash

    FMVSS No. 305 requires that after a crash, each high voltage source 
in the vehicle are either electrically isolated from the vehicle's 
chassis, or their voltage is reduced to levels considered safe from 
electric shock hazards (i.e., less than 30 VAC or less than 60 VDC).
    As noted in earlier sections, GTR No. 13 specifies that vehicles 
may meet regulatory requirements by having no high voltage levels (see 
(a) below), meet physical barrier protection requirements (see (b)) 
below, or meet electrical isolation requirements (see (c) below):

    a. Voltage levels: The voltages of the high voltage source must 
be less than or equal to 30 VAC or 60 VDC within 60 seconds after 
the impact. (This option for electrical safety is currently in FMVSS 
No. 305.)
    b. Electrical protection barrier: The physical protection 
requirement is an option each contracting party of the 1998 
agreement may elect to adopt. The provision is similar to the 
electrical safety requirements during normal operations except that 
the protection degree IPXXB applies rather than IPXXD. (The 
provision for electrical protection through physical barriers is 
currently not in FMVSS No. 305.)
    i. Protection from direct contact: Protection from direct 
contact of high voltage sources with protection degree IPXXB 
required.
    ii. Protection from indirect contact: The resistance between all 
exposed conductive parts and electrical chassis is required to be 
less than 0.1 ohms when there is a current flow of at least 0.2 
A.\60\
---------------------------------------------------------------------------

    \60\ GTR No. 13 considers this requirement to be met if visual 
inspection indicates that conductive connection has been established 
by welding. The minimum resistance requirement is only evaluated in 
case of doubt.
---------------------------------------------------------------------------

    c. Electrical isolation:
    i. If the AC and DC high voltage sources are conductively 
isolated from each other, then the minimum electrical isolation of a 
high voltage source to the chassis is 500 ohms/volt for AC 
components and 100 ohms/volt for DC components of the working 
voltage.
    ii. If AC and DC high voltage sources are conductively 
connected, the minimum electrical isolation of AC and DC high 
voltage sources must be--
     500 ohms/volt of the working voltage, or
     100 ohms/volt of the working voltage with the AC high 
voltage sources meeting the physical protection requirements in (b) 
or have no high voltage as specified in (a).

    (FMVSS No. 305 does not distinguish AC and DC high voltage sources 
that are conductively connected from those that are isolated. Thus, the 
method above for complying with electrical isolation requirements when 
AC and DC high voltage sources are connected post-crash (see c. ii. 
above) is not now available in FMVSS No. 305.)

Proposal

    This NPRM proposes to amend the isolation resistance compliance 
option in FMVSS No. 305 to harmonize with GTR No. 13. We are proposing 
to add an optional method of meeting post-crash electrical isolation 
requirements for an AC high voltage source that is connected to a DC 
high voltage source. In such condition, the required minimum electrical 
isolation for the AC high voltage source is 100 ohms/volt provided the 
AC high voltage source meets the post-crash physical barrier protection 
requirements.
    We are also proposing to add a physical barrier protection option 
for post-crash electrical safety that includes requirements specifying 
that:

    i. High voltage sources must be enclosed in barriers that 
prevent direct human contact with high voltage sources (IPXXB 
protection level),
    ii. Electrical protection barriers must be conductively 
connected to the chassis with a resistance less than 0.1 ohms, and 
the resistance between two simultaneously reachable exposed 
conductive parts of electrical protection barriers that are less 
than 2.5 meters of each other must be less than 0.2 ohms, and
    iii. Voltage between a barrier and other exposed conductive 
parts of the vehicle must be at a low voltage level that would not 
cause electric shock (less than 60 VDC or 30 VAC).

Electrical Isolation Resistance Option

    Currently, FMVSS No. 305's electrical isolation option requires 
that vehicles with high voltage sources meet different isolation 
requirements based on whether the vehicle is an AC or a DC high voltage 
source. Electric powered vehicles are required to electrically isolate 
AC and DC high voltage sources from the chassis with electrical 
isolation no less than 500 ohms/volt, but the DC high voltage source 
can have electrical isolation no less than 100 ohms/volt if

[[Page 12666]]

the DC high voltage source has an electrical isolation monitoring 
system.
    GTR No. 13 differs from FMVSS No. 305 by distinguishing between 
situations where AC and DC high voltage are conductively isolated from 
each other or are conductively connected. GTR No. 13 states that when 
AC and DC high voltage sources are isolated from each other, the AC 
high voltage sources need to maintain electrical isolation no less than 
500 ohms/volt and DC sources need to maintain electrical isolation no 
less than 100 ohms/volt. This is similar to FMVSS No. 305.\61\
---------------------------------------------------------------------------

    \61\ We note that GTR No. 13 permits DC high voltage sources to 
have 100 ohms/volt minimum electrical isolation without specifying 
that the DC high voltage sources must be equipped with an electrical 
isolation monitoring system. While this appears to differ from FMVSS 
No. 305, we do not believe there is a practical difference. The only 
vehicles needing to use FMVSS No. 305's 100 ohms/volt electrical 
isolation compliance option for DC high voltage sources are fuel 
cell vehicles. In this NPRM, the agency is proposing to require all 
DC high voltage sources of fuel cell vehicles to be equipped with an 
electrical isolation monitoring system. Therefore, while we propose 
to adopt the post-crash electrical isolation requirements for DC 
high voltage sources in GTR No. 13 into FMVSS No. 305 to further 
harmonization efforts, we do not believe there would be an effect on 
vehicle design or safety.
---------------------------------------------------------------------------

    When the AC and DC sources are conductively connected, GTR No. 13 
affords three different methods for these high voltage sources to 
achieve compliance:
    (1) All AC and DC sources maintain minimum electrical isolation of 
500 ohms/volt (this is basically the approach of FMVSS No. 305);
    (2) AC high voltage sources that are linked to a DC high voltage 
source may have a minimum of 100 ohms/volt instead of 500 ohms/volt if 
the AC high voltage source also has physical barrier protection from 
direct and indirect contact of high voltage sources; \62\ or
---------------------------------------------------------------------------

    \62\ FMVSS No. 305 does not distinguish when the AC and DC 
sources are connected from when AC and DC sources are separated. The 
standard specifies that all AC high voltage sources must have a 
minimum electrical isolation of 500 ohms/volt. The condition 
involving connected AC and DC high voltage sources is germane to the 
Toyota petition.
---------------------------------------------------------------------------

    (3) all AC and DC sources maintain a minimum isolation resistance 
of 100 ohms/volt and all AC sources meet low-voltage requirements in 
GTR No. 13.

Need for Amendment

    After reviewing the Toyota petition and other information, NHTSA 
understands petitioners' concern about FMVSS No. 305's electrical 
isolation requirements for AC high voltage sources under the conditions 
when the AC and DC bus are conductively connected. We tentatively 
believe that an amendment is warranted to facilitate the manufacture of 
fuel cell and other vehicles.
    If FMVSS No. 305 were not amended, the electrical isolation for 
fuel cell stacks would need to be 500 ohms/volt or greater to comply 
with FMVSS No. 305, which may not be technically feasible.

Proposal for Electrical Isolation Option

    In consideration of the above, NHTSA is proposing to add an option 
that would permit an AC high voltage source that is connected to a DC 
high voltage source post-crash to have electrical isolation no less 
than 100 ohms/volt provided the high voltage source also meets physical 
barrier protection requirements. Specifically, the electrical isolation 
option for electrical safety in the proposal requires that the 
electrical isolation of a high voltage source be greater than or equal 
to one of the following:
    (1) 500 ohms/volt for an AC high voltage source; or
    (2) 100 ohms/volt for an AC high voltage source if it is 
conductively connected to a DC high voltage source, but only if the AC 
high voltage source meets the physical barrier protection requirements; 
or
    (3) 100 ohms/volt for a DC high voltage source.
    NHTSA tentatively believes that adding this option into the 
existing FMVSS No. 305 requirements essentially harmonizes with the 
electrical isolation option in GTR No. 13. When an AC and DC high 
voltage source are conductively connected, the electrical isolation 
measured will be the same for both high voltage sources and 
approximately equal to the lower electrical isolation measurement of 
the two. Accordingly, the combined electrical isolation of conductively 
connected AC and DC high voltage sources can be greater than or equal 
to 500 ohm/volt only if the electrical isolation of each AC and DC high 
voltage sources are greater than or equal to 500 ohms/volt. Therefore 
the first option for electrical isolation in GTR No. 13 when an AC and 
DC high voltage source are conductively connected is redundant to what 
is already in FMVSS No. 305 since it is equivalent to the electrical 
isolation requirement when the AC and DC high voltage sources are 
conductively isolated from each other. The third option for electrical 
isolation in GTR No. 13 is unnecessary because if an AC high voltage 
source meets low voltage requirements, there is no need to meet the 
electrical isolation requirements.
    We note, however, that the physical barrier protection requirement 
in the proposed regulatory language to accommodate a lower electrical 
isolation level for a AC high voltage source that is conductively 
connected to a DC high voltage source is not the same as that specified 
in GTR No. 13. The physical barrier protection requirement is an option 
each contracting party of the 1998 agreement may elect to adopt. As 
explained in the following section, although our proposal in this 
document chooses not to adopt the physical barrier option in GTR No. 13 
per se, we are proposing to adopt a modified physical barrier option. 
Based on the information from the Battelle research, the Alliance 
petition, the Toyota petition and other sources, we tentatively believe 
that our proposed physical barrier option will afford the compliance 
flexibility that the manufacturers desire while providing a level of 
safety that is more comparable to the other post-crash electric shock 
compliance options.

Physical Barrier Protection

Need for Amendment
    The Alliance petition for rulemaking requested updates to FMVSS No. 
305 for facilitating the development and sale of not only HFCVs but 
also 48 volt mild hybrid vehicles. Because 48 volt batteries are 
considered low voltage, the 48 volt mild hybrid systems are designed 
with conductive connection to the electric chassis and so are unable to 
provide electrical isolation. While most parts of the 48 volt mild 
hybrid system would be considered low voltage per the measurement to 
the chassis, the voltage between different phases of the 3-phase AC 
motor can be slightly greater than 30 VAC and so would be considered a 
high voltage source.

The Alliance Petition

    The agency has considered the information provided by the Alliance 
and by Mercedes-Benz \63\ and tentatively concludes that without an 
electrical protection barrier option, 48 volt mild hybrids will not be 
a practical consideration for improving fuel economy. In the absence of 
such an option, these systems will need to be electrically isolated 
from the chassis and thereby result in higher mass, reduced fuel 
economy, increased emissions, and higher consumer costs.
---------------------------------------------------------------------------

    \63\ We discussed the Mercedes-Benz information earlier in this 
preamble, in the section describing the Alliance's petition for 
rulemaking, supra. 48 V Systems--Powerful Innovative Technologies 
for 2020 FC Targets, Mercedes-Benz, Daimler AG, June 2, 2015. 
Available in the docket for this NPRM.
---------------------------------------------------------------------------

    Regarding the Battelle study, we first begin by noting that we 
agree with the Alliance's analysis that for electric

[[Page 12667]]

powered vehicles that meet the electrical isolation and physical 
barrier protection requirement in GTR No. 13 during normal vehicle 
operation, there is a very low likelihood that the various safety 
critical scenarios identified in the Battelle report with electric 
shock potential would occur. The scenarios would only be possible if 
multiple failures of safety systems occurred, along with human contact 
to very specific locations. Be that as it may, the Alliance petition 
also suggested modifications to the electrical protection barrier 
provisions in GTR No. 13, which it states provide the same level of 
protection as the electrical isolation option for electrical safety in 
FMVSS No. 305 along with protection from the safety critical scenarios 
identified in the Battelle report.
    The physical barrier protection option in the Alliance petition 
specifies two optional methods of providing physical barrier protection 
from direct and indirect contact of high voltage sources. The first 
method (Option 1) requires an AC or DC high voltage source to have:
    1. Direct contact protection degree IPXXB,
    2. All exposed conductive parts of electrical protection barriers 
are conductively connected to electrical chassis with resistance less 
than 0.1 ohms, and
    3. The electrical isolation between the high voltage source and the 
electrical protection barrier enclosing it is greater than or equal to 
0.05 ohms/VAC or 0.01 ohms/VDC.
    The second method (Option 2) requires an AC or DC high voltage 
source to have:
    1. Direct contact protection degree IPXXB.
    2. The voltage between the electrical protection barrier and other 
exposed conductive parts is low voltage (30 VAC or 60 VDC).

Technical Analysis

    The physical barrier protection provides electrical safety via 
electrical protection barriers that are placed around high voltage 
components to insure that there is no direct or indirect human contact 
with live high voltage sources during normal vehicle operation or after 
a vehicle crash. For protection against contact with live parts in 
post-crash conditions, a test probe designed to simulate a small human 
finger (12 mm) conforming to ISO 20653 ``Road vehicles--Degrees of 
protection (IP-Code)--Protection of electrical equipment against 
foreign objects, water, and access (IPXXB)'' is specified in GTR No. 
13.\64\ The agency notes that protection against direct contact of high 
voltage sources is currently not specified in FMVSS No. 305 and so 
adding such a provision into FMVSS No. 305 would further enhance 
protection from electric shock. The IPXXB finger probe is utilized in 
other standards \65\ for protecting electrical maintenance personnel 
from inadvertently contacting high voltage during servicing of 
electrical equipment. Therefore, NHTSA tentatively believes protection 
level using the simulated human finger probe (IPXXB) to prohibit 
inadvertent contact by passengers and first responders with high 
voltage components contained within protective enclosures is 
appropriate.\66\
---------------------------------------------------------------------------

    \64\ IEC60529 Second edition 1989-11 + Am. 1 1999-11, EN60529, 
``Degrees of protection provided by enclosures.''
    \65\ For example, IEC 60479, ``Low voltage switchgear and 
control gear assemblies,'' uses IPXXB level protection for 
preventing contact with high voltage sources by maintenance 
personnel. The voltage levels considered in IEC 60479 are similar to 
those in automotive application.
    \66\ The use of the IPXXB finger probe as opposed to the IPXXD 
wire probe for evaluating direct contact protection after a crash 
test is appropriate. The IPXXD is intended to evaluate contact with 
high voltage sources inside the passenger or luggage compartment 
during normal vehicle operation to ensure that body parts, 
miscellaneous tools or other slender conductive items typically 
encountered in a passenger or luggage compartment cannot penetrate 
any gaps/seams in the protective enclosures and contact high voltage 
components contained within.
---------------------------------------------------------------------------

    NHTSA reviewed \67\ the Alliance's proposal for a post-crash 
electrical protection barrier option for FMVSS No. 305 and confirmed 
that the electric current Ib through the body (with minimum resistance 
of 500 ohms) in Figure 9, supra, is less than or equal to 10 mA DC or 
less than or equal to 2 mA AC under various scenarios, as long as the 
three requirements for the Alliance-suggested Option 1 for post-crash 
physical barrier protection are met. These are: 1. Direct contact 
protection degree IPXXB, 2. all exposed conductive parts are 
conductively connected to electrical chassis with resistance less than 
0.1 ohms, and 3. the combined resistance of R1 and 
R2 and the resistance of the conductive connection of the 
electrical protection barrier to the chassis is greater than or equal 
to 0.05 ohms/VAC or 0.01 ohms/VDC. When all three conditions in the 
Option 1 physical barrier protection suggested by Alliance are met, the 
agency's analysis showed that in the event of loss in electrical 
isolation, the body current is limited to safe levels under the various 
safety critical scenarios identified in the Battelle study. The 
agency's analysis also confirmed that when the above conditions are 
met, the voltage between barrier #1 and barrier #2 in Figure 9 is less 
than or equal to 30 VAC or 60 VDC, as the Alliance noted.\68\
---------------------------------------------------------------------------

    \67\ Supporting technical document in the docket of this NPRM.
    \68\ For example, an analysis of the circuit in Figure 9 was 
conducted using the following values for the components in the 
circuit: Vb = 1000 VDC, bonding resistance bond #1 and bond #2 equal 
to 0.1 ohm, R1 and R2 resistances equal to 20 ohms, and body 
resistance equal to 500 ohms. This resulted in a combined resistance 
of R1 and R2 and bonding resistance to chassis 
of 10.05 ohms (or 0.01005 ohms/volt electrical isolation from the 
chassis) and current through the body of 9.95 mA (<10 mA considered 
as safe level of current). The analysis also showed that in this 
example, the voltage between barrier #1 and barrier #2 is equal to 
4.97 volt (<60 volt is considered to be low voltage). This is 
further explained in the supporting technical document in the docket 
of this NPRM.
---------------------------------------------------------------------------

    The specification that the conductive connection between a 
protection barrier and the chassis be less than 0.1 ohm provides 
protection from electric shock by shunting any harmful electrical 
currents through the vehicle chassis (rather than through a human 
contacting the protection barrier) should any electrically charged 
components lose isolation within the protective barrier. The 0.1 ohms 
resistance level for electrical bonding (or conductive connection) is 
well established in international standards both in and out of the 
automotive industry (e.g. MIL_B_5087, NASA Technical Standard NSA-STD-
P023 ``Electrical Bonding for NASA Launch Vehicles, Payloads, and 
Flight Equipment,'' ISO6469, ECE-R100, and IEC 60335-1 ``Household and 
Similar Electrical Appliances'' Part 1: General Requirements). For 
these reasons, NHTSA accepts that the resistance of the conductive 
connection between the protective barrier and the electrical chassis be 
less than 0.1 ohms.
    However, the agency sought clarification on the indirect contact 
protection requirement of Option 1 suggested by the Alliance, which 
states that, ``The resistance between exposed conductive parts of the 
electrical protection barrier(s) and the electrically conductive 
chassis is less than 0.1 ohms where there is a current flow of at least 
0.2 A.'' NHTSA noted that the maximum allowable resistance for the 
electrical chassis was not specified and asked the Alliance how its 
suggested Option 1 would afford adequate indirect contact protection 
when exposed conductive parts of two electrical protection barriers 
were contacted simultaneously instead of simultaneous contact of an 
electrical protection barrier and the chassis.

[[Page 12668]]

    In response,\69\ the Alliance acknowledged that the effective 
resistance between two exposed conductive parts of the electrical 
protection barriers was not well defined in its proposal. The 
petitioner stated that in order to address the fact that there are no 
resistance specifications for the electrically conductive chassis, it 
recommends the addition of a performance requirement that limits the 
maximum resistance between any two exposed conductive parts of the 
electrical protection barriers to less than 0.2 ohms (which corresponds 
to the requirement that maximum resistance between the protective 
physical barrier and the electrical chassis is less than 0.1 ohms). The 
Alliance also stated that the resistance measurements between any two 
exposed conductive parts of the electrical protection barriers should 
be limited to those that can be simultaneously contacted by a human. 
The petitioner stated its belief that limiting the resistance 
measurement to a distance of 2.5 meter \70\ would ensure that any 
surfaces that can be simultaneously contacted by a human be subjected 
to the proposed performance requirements. The petitioner noted that 
such a distance limitation would significantly reduce the test burden 
(number of test points) while maintaining the same level of safety. 
Accordingly, the Alliance offered the following modification to the 
text in SAE J1766 regarding indirect contact protection requirements 
and requested that NHTSA seek comment on it in an NPRM.
---------------------------------------------------------------------------

    \69\ Alliance's response to NHTSA's questions is in the docket 
of this NPRM.
    \70\ This distance specification was obtained from IEC 60364-4-
41. ``Low-voltage electrical installations--Part 4-4--Protection 
against electric shock.'': Annex B (Obstacles and Placing out of 
Reach), and ISO6469-3,:2011, ``Electrically propelled road 
vehicles--Safety specifications--Part 3: Protection of persons 
against electric shock.''

    [Petitioner's suggested requirement] S5.3.4(2)--The bonding 
resistance between any exposed conductive parts of the electrical 
protection barriers and the vehicle's electrical chassis shall not 
exceed 0.1 ohms. This requirement is deemed satisfied if the 
galvanic connection has been made by welding and the weld is intact 
after each of the specified crash tests. In addition, the bonding 
resistance between any two simultaneously reachable exposed 
conductive parts of the electrical protection barriers in a distance 
of 2.5 meters shall not exceed 0.2 ohms. See C.2.1 for the 
---------------------------------------------------------------------------
applicable test procedure.

    The agency tentatively concludes that this modification responds to 
NHTSA's concern about the lack of resistance specification for the 
electrical chassis and the lack of low resistance specification between 
two electrical protection barriers that can be contacted 
simultaneously.\71\ However, we note that the requirement in the 
suggested S5.3.4(2) above is for the resistance to be less than or 
equal to 0.1 ohms and 0.2 ohms, while SAE J1766 January 2014 and GTR 
No. 13 specify that the resistance be less than 0.1 ohms. For purposes 
of harmonization with GTR No. 13, the agency proposes to use ``less 
than 0.1 ohms'' and ``less than 0.2 ohms.''
---------------------------------------------------------------------------

    \71\ NHTSA's analysis using 0.2 ohm resistance (instead of 0.1 
ohm) between two protective barriers along with IPXXB protection and 
isolation between high voltage source and the protective barrier of 
0.01 ohm/VDC or 0.05 ohm/VAC results in safe current levels through 
the body (10 mA DC or 2 mA AC). See details of NHTSA's analysis in 
the supporting technical document in the docket of this NPRM.
---------------------------------------------------------------------------

    The proposed modification suggested by the Alliance also states, 
``This requirement is deemed satisfied if the galvanic connection has 
been made by welding and the weld is intact after each of the specified 
crash tests.'' We believe that such a method of assessing compliance of 
indirect contact protection by visually inspecting the welding lacks 
objectivity that is needed for FMVSS. Therefore, NHTSA proposes not 
including this method for evaluating compliance. Instead, the agency 
proposes to include the test procedure in GTR No. 13 and SAE J1766 
January 2014 that determines the resistance between an electrical 
protection barrier and the chassis and between two electrical 
protection barriers by passing through a current of at least 0.2 A. 
NHTSA seeks comment on its proposal not to include assessing compliance 
of a conductive connection by means of visual inspection.
    The agency's review had also indicated that the Alliance's proposed 
Option 2 for physical barrier protection (direct contact protection 
degree IPXXB and the voltage between barrier #1 and barrier #2 is less 
than or equal to 30 VAC or 60 VDC) does not guarantee that the current 
through the body is less than 10 mA DC and 2 mA AC for all 
scenarios.\72\ NHTSA requested that the Alliance provide clarification 
on this matter. The Alliance responded \73\ that FMVSS No. 305 already 
recognizes these low voltage thresholds, both with respect to the 
applicability of the standard and with respect to the electrical safety 
provisions of the standard. The Alliance also noted that GTR No. 13 and 
numerous other government regulations and industry standards recognize 
these low voltage threshold levels for automotive applications.\74\ The 
Alliance observed that for voltage below or equal to 30 VAC and 60 VDC, 
the potential body current is below the let-go limit \75\ and below the 
limit for electric shock with non-reversible harm. The Alliance stated 
that it is for these reasons that voltage levels below 30 VAC and 60 
VDC are designated worldwide as low voltage without safety concern.\76\
---------------------------------------------------------------------------

    \72\ For example, an analysis of the circuit in Figure 9 was 
conducted using the following values for the components in the 
circuit: Vb = 1000 VDC, bonding resistance bond #1 and bond #2 equal 
to 0.1 ohm, R1 and R2 resistances equal to 1.6 ohms, and body 
resistance equal to 500 ohms. This resulted in a combined resistance 
of R1 and R2 and bonding resistance to chassis 
of 0.85 ohms (or 0.00085 ohms/volt electrical isolation from 
chassis) and current through the body of 117 mA (>10 mA is 
considered an unsafe level of current). The analysis also showed 
that in this example, the voltage between barrier #1 and barrier #2 
is equal to 58.52 volt (<60 volt is considered to be low voltage). 
This is further explained in the supporting technical document in 
the docket of this NPRM.
    \73\ Alliance's response to NHTSA's questions is in the docket 
of this NPRM.
    \74\ Electrical safety requirements in Europe, Japan, and Korea 
and SAE J1766 recognize voltage levels less than or equal to 30 VAC 
or 60 VDC as low voltage.
    \75\ Maximum value of touch current at which a person holding 
electrodes can let go of the electrodes.
    \76\ The Alliance also noted its belief that the indirect 
contact scenarios identified in the Battelle study are extremely 
rare and that in setting appropriate safety measures, the 
probability of faults, probability of contact with live parts, and 
the ratio of touch voltage and fault voltage needs to be considered.
---------------------------------------------------------------------------

    NHTSA tentatively agrees with the clarification provided by the 
Alliance that voltage levels at or lower than 30 VAC and 60 VDC are 
already specified as low voltage in FMVSS No. 305 and at these voltage 
levels, the potential body current is below the limit for electric 
shock. Currently, the European Union, Japan, and Korea, permit 
compliance for electrical safety using the electrical protection 
barrier option in GTR No. 13 and NHTSA is not aware of any incidence of 
electrical shock during normal operation and after a crash.
    The Alliance suggested adopting Option 2 for physical barrier 
protection rather than Option 1 because it is difficult to measure 
electrical isolation between the high voltage source and exposed 
conductive parts of its electrical protection barrier, which is needed 
to assess compliance with Option 1.\77\ Additionally, the agency's 
analysis confirms that of the Alliance's, that if the three conditions 
of Option 1 are met, the two conditions of Option 2 would also be met 
and in the event of loss of electrical isolation, the current through a 
body contacting electrical protection barriers is within safe levels

[[Page 12669]]

(same level of safety as that afforded by post-crash electrical 
isolation requirements).
---------------------------------------------------------------------------

    \77\ The Alliance did not specify a test procedure to determine 
electrical isolation between the high voltage source and its 
electrical protection barrier.
---------------------------------------------------------------------------

NHTSA's Proposal for Physical Barrier Protection

    In consideration of the above technical analysis, the agency is 
proposing to combine Alliance's suggested Option 1 and Option 2 
requirements for electrical protection barriers. Specifically, the 
agency proposes the following requirements for an electrical protection 
barrier of a high voltage source:
    (1) Direct contact protection degree IPXXB,
    (2) indirect contact protection (electrical protection barriers are 
conductively connected to the chassis with resistance less than 0.1 
ohms and resistance between two electrical protection barriers that are 
accessible within 2.5 meters is less than 0.2 ohms), and
    (3) low voltage of 30 VAC or 60VDC between the electrical 
protection barrier and other exposed conductive parts.
    The first two conditions are specified in GTR No. 13 and (1) and 
(3) together is the same as Option 2 suggested by the Alliance. We 
concur that there is merit to the third condition since FMVSS No. 305 
already recognizes voltages less than or equal to 30 VAC and 60 VDC as 
low voltage. Our technical analysis confirms that the proposed post-
crash physical barrier protection option (with the first two 
requirements in GTR No. 13 and an additional third requirement that 
electrical protection barriers be low voltage) affords the same level 
of safety as the post-crash electrical isolation option currently in 
FMVSS No. 305.
    NHTSA seeks comment on the proposed inclusion of the physical 
barrier protection option into FMVSS No. 305. NHTSA also seeks comment 
on its proposed physical barrier protection requirements which combine 
the requirements in GTR No. 13 and Option 2 in the Alliance petition. 
The agency also seeks comment on the proposed test procedures for 
assessing physical barrier protection.

Toyota's Request for Amending Post-Crash Test Procedure

    In its December 23, 2013 petition for rulemaking, Toyota requests 
that NHTSA amend S6.4 of FMVSS No. 305, which requires a vehicle to 
satisfy all of the post-crash performance requirements ``after being 
rotated on its longitudinal axis to each successive increment of 90 
degrees. . . .'' Toyota recommends that the tests to evaluate 
electrical isolation and physical barrier protection requirements be 
performed after the vehicle is rotated a full 360 degrees. Toyota 
states that the vehicle conditions related to these requirements do not 
change at various increments of a rollover, and it would be 
increasingly dangerous for laboratory personnel to conduct the 
specified tests with the vehicle at other 90 degree increments.
    NHTSA has evaluated Toyota's request and is denying it. NHTSA does 
not agree with Toyota's assessment that the vehicle conditions related 
to electrical safety requirements do not change at various increments 
of rollover. Post-crash direct contact protection is assessed by first 
opening, disassembling, or removing electrical protection barriers, 
solid insulator, and connectors without the use of tools, and then the 
IPXXB probe is used to determine if high voltage sources can be 
contacted. This evaluation may yield different results for the 
different attitudes of the vehicle. For example, high voltage sources 
may be more accessible when the vehicle is rotated 90 degrees than when 
upright. NHTSA is not aware of unreasonably dangerous conditions to 
laboratory personnel in conducting the specified tests with the vehicle 
at 90 degree increments. Toyota did not provide any supporting data to 
substantiate its case. NHTSA seeks comment on this issue.

X. Rulemaking Analyses and Notices

Executive Order 12866 and DOT Regulatory Policies and Procedures

    This rulemaking document was not reviewed by the Office of 
Management and Budget under E.O. 12866. It is not considered to be 
significant under E.O. 12866 or the Department's Regulatory Policies 
and Procedures. The amendments proposed by this NPRM would have no 
significant effect on the national economy, as the requirements are 
already in voluntary industry standards and international standards 
that current electric powered vehicles presently meet.
    This NPRM proposes to update FMVSS No. 305 to incorporate the 
electrical safety requirements in GTR No. 13. This proposal also 
responds to petitions for rulemaking from Toyota and the Alliance to 
facilitate the introduction of fuel cell vehicles and 48 volt mild 
hybrid technologies into the vehicle fleet. The proposal adds 
electrical safety requirements in GTR No. 13 that involves electrical 
isolation and direct and indirect contact protection of high voltage 
sources to prevent electric shock during normal operation of electric 
powered vehicles. Today's proposal also provides an additional optional 
method of meeting post-crash electrical safety requirements in FMVSS 
No. 305 that involves physical barriers of high voltage sources to 
prevent electric shock due to direct and indirect contact with live 
parts. Since there is widespread conformance with the requirements that 
would apply to existing vehicles, we anticipate no costs or benefits 
associated with this rulemaking.

Regulatory Flexibility Act

    NHTSA has considered the effects of this NPRM under the Regulatory 
Flexibility Act (5 U.S.C. 601 et seq., as amended by the Small Business 
Regulatory Enforcement Fairness Act (SBREFA) of 1996). I certify that 
this NPRM would not have a significant economic impact on a substantial 
number of small entities. Any small manufacturers that might be 
affected by this NPRM are already subject to the requirements of FMVSS 
No. 305. Further, the agency believes the testing associated with the 
requirements added by this NPRM are not substantial and to some extent 
are already being voluntarily borne by the manufacturers pursuant to 
SAE J1766. Therefore, there will be only a minor economic impact.

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.

Executive Order 13132 (Federalism)

    NHTSA has examined today's NPRM 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 proposal does not have sufficient federalism implications to 
warrant consultation with State and local officials or the preparation 
of a federalism summary impact statement. The proposal 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.''
    NHTSA rules can have preemptive effect in two ways. First, the 
National Traffic and Motor Vehicle Safety Act contains an express 
preemption provision:
    When a motor vehicle safety standard is in effect under this 
chapter, a State or a political subdivision of a State may

[[Page 12670]]

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. 49 U.S.C. 30103(b)(1).
    It is this statutory command that preempts any non-identical State 
legislative and administrative law \78\ addressing the same aspect of 
performance, not today's rulemaking, so consultation would be 
inappropriate.
---------------------------------------------------------------------------

    \78\ The issue of potential preemption of state tort law is 
addressed in the immediately following paragraph discussing implied 
preemption.
---------------------------------------------------------------------------

    Second, the Supreme Court has recognized the possibility, in some 
instances, of implied preemption of State requirements imposed on motor 
vehicle manufacturers, including sanctions imposed by State tort law. 
That possibility is dependent upon there being an actual conflict 
between a FMVSS and the State requirement. If and when such a conflict 
exists, the Supremacy Clause of the Constitution makes the State 
requirements unenforceable. See Geier v. American Honda Motor Co., 529 
U.S. 861 (2000), finding implied preemption of state tort law on the 
basis of a conflict discerned by the court,\79\ not on the basis of an 
intent to preempt asserted by the agency itself.
---------------------------------------------------------------------------

    \79\ The conflict was discerned based upon the nature (e.g., the 
language and structure of the regulatory text) and the safety-
related objectives of FMVSS requirements in question and the impact 
of the State requirements on those objectives.
---------------------------------------------------------------------------

    NHTSA has considered the nature (e.g., the language and structure 
of the regulatory text) and objectives of today's NPRM and does not 
discern any existing State requirements that conflict with the rule or 
the potential for any future State requirements that might conflict 
with it. Without any conflict, there could not be any implied 
preemption of state law, including state tort law.

Executive Order 12988 (Civil Justice Reform)

    With respect to the review of the promulgation of a new regulation, 
section 3(b) of Executive Order 12988, ``Civil Justice Reform'' (61 FR 
4729; Feb. 7, 1996), requires that Executive agencies make every 
reasonable effort to ensure that the regulation: (1) Clearly specifies 
the preemptive effect; (2) clearly specifies the effect on existing 
Federal law or regulation; (3) provides a clear legal standard for 
affected conduct, while promoting simplification and burden reduction; 
(4) clearly specifies the retroactive effect, if any; (5) specifies 
whether administrative proceedings are to be required before parties 
file suit in court; (6) adequately defines key terms; and (7) addresses 
other important issues affecting clarity and general draftsmanship 
under any guidelines issued by the Attorney General. This document is 
consistent with that requirement.
    Pursuant to this Order, NHTSA notes as follows. The issue of 
preemption is discussed above. NHTSA notes further that there is no 
requirement that individuals submit a petition for reconsideration or 
pursue other administrative proceedings before they may file suit in 
court.

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 http://www.dot.gov/privacy.html.

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 NPRM.

National Technology Transfer and Advancement Act

    Section 12(d) of the National Technology Transfer and Advancement 
Act of 1995 (NTTAA), Public Law 104-113, as amended by Public Law 107-
107 (15 U.S.C. 272), directs the agency to evaluate and use voluntary 
consensus standards in its regulatory activities unless doing so would 
be inconsistent with applicable law or is otherwise impractical. 
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) with 
explanations when the agency decides not to use available and 
applicable voluntary consensus standards. The NTTAA does not apply to 
symbols.
    FMVSS No. 305 has historically drawn largely from SAE J1766, and 
does so again for this current rulemaking, which proposes revisions to 
FMVSS No. 305 to facilitate the development of fuel cell and 48 volt 
mild hybrid technologies. It is based on GTR No. 13 and the latest 
version of SAE J1766 January 2014.

Unfunded Mandates Reform Act

    Section 202 of the Unfunded Mandates Reform Act of 1995 (UMRA), 
Public Law 104-4, requires Federal 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). Adjusting this amount by the 
implicit gross domestic product price deflator for the year 2013 
results in $142 million (106.733/75.324 = 1.42). This NPRM would not 
result in a cost of $142 million or more to either State, local, or 
tribal governments, in the aggregate, or the private sector. Thus, this 
NPRM is not subject to the requirements of sections 202 of the UMRA.

Executive Order 13609 (Promoting Regulatory Cooperation)

    The policy statement in section 1 of Executive Order 13609 
provides, in part: The regulatory approaches taken by foreign 
governments may differ from those taken by U.S. regulatory agencies to 
address similar issues. In some cases, the differences between the 
regulatory approaches of U.S. agencies and those of their foreign 
counterparts might not be necessary and might impair the ability of 
American businesses to export and compete internationally. In meeting 
shared challenges involving health, safety, labor, security, 
environmental, and other issues, international regulatory cooperation 
can identify approaches that are at least as protective as those that 
are or would be adopted in the absence of such cooperation. 
International regulatory cooperation can also reduce, eliminate, or 
prevent unnecessary differences in regulatory requirements.
    The agency participated in the development of GTR No. 13 to 
harmonize the standards of fuel cell vehicles. As a signatory member, 
NHTSA is proposing to incorporate electrical safety requirements and 
options specified in GTR No. 13 into FMVSS No. 305.

Regulation Identifier Number

    The Department of Transportation assigns a regulation identifier 
number (RIN) to each regulatory action listed in the Unified Agenda of 
Federal

[[Page 12671]]

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.

Plain Language

    Executive Order 12866 requires each agency to write all rules in 
plain language. Application of the principles 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 write to us 
with your views.

XI. Public Participation

How do I prepare and submit comments?

    Your comments must be written and in English. To ensure that your 
comments are correctly filed in the Docket, please include the docket 
number of this document in your comments.
    Your comments must not be more than 15 pages long. (49 CFR 553.21). 
We established this limit to encourage you to write your primary 
comments in a concise fashion. However, you may attach necessary 
additional documents to your comments. There is no limit on the length 
of the attachments.
    Comments may also be submitted to the docket electronically by 
logging onto the Docket Management System Web site at http://www.regulations.gov. Follow the online instructions for submitting 
comments.
    Please note that pursuant to the Data Quality Act, in order for 
substantive data to be relied upon and used by the agency, it must meet 
the information quality standards set forth in the OMB and DOT Data 
Quality Act guidelines. Accordingly, we encourage you to consult the 
guidelines in preparing your comments. OMB's guidelines may be accessed 
at http://www.whitehouse.gov/omb/fedreg/reproducible.html.

How can I be sure that my comments were received?

    If you wish Docket Management to notify you upon its receipt of 
your comments, enclose a self-addressed, stamped postcard in the 
envelope containing your comments. Upon receiving your comments, Docket 
Management will return the postcard by mail.

How do I submit confidential business information?

    If you wish to submit any information under a claim of 
confidentiality, you should submit three copies of your complete 
submission, including the information you claim to be confidential 
business information, to the Chief Counsel, NHTSA, at the address given 
above under FOR FURTHER INFORMATION CONTACT. In addition, you should 
submit a copy, from which you have deleted the claimed confidential 
business information, to the docket at the address given above under 
ADDRESSES. When you send a comment containing information claimed to be 
confidential business information, you should include a cover letter 
setting forth the information specified in our confidential business 
information regulation. (49 CFR part 512)

Will the agency consider late comments?

    We will consider all comments received before the close of business 
on the comment closing date indicated above under DATES. To the extent 
possible, we will also consider comments that the docket receives after 
that date. If the docket receives a comment too late for us to consider 
in developing a final rule (assuming that one is issued), we will 
consider that comment as an informal suggestion for future rulemaking 
action.

How can I read the comments submitted by other people?

    You may read the comments received by the docket at the address 
given above under ADDRESSES. The hours of the docket are indicated 
above in the same location. You may also see the comments on the 
Internet. To read the comments on the Internet, go to http://www.regulations.gov. Follow the online instructions for accessing the 
dockets.
    Please note that even after the comment closing date, we will 
continue to file relevant information in the docket as it becomes 
available. Further, some people may submit late comments. Accordingly, 
we recommend that you periodically check the Docket for new material. 
You can arrange with the docket to be notified when others file 
comments in the docket. See www.regulations.gov for more information.

List of Subjects in 49 CFR Part 571

    Imports, Motor vehicles, Motor vehicle safety.

    In consideration of the foregoing, NHTSA proposes to amend 49 CFR 
part 571 as follows:

PART 571--FEDERAL MOTOR VEHICLE SAFETY STANDARDS

0
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 1.95.

0
2. In Sec.  571.305:
0
a. Revise S1 and S2;
0
b. Under S4:
0
i. Add in alphabetical order definitions for ``Charge connector'', 
``Direct contact'', ``Electrical protection barrier'', ``Exposed 
conductive part'', ``External electric power supply'', ``Fuel cell 
system'', ``Indirect contact'', ``Live part'', ``Luggage compartment'', 
``Passenger compartment'', and ``Possible active driving mode'';
0
ii. Revise the definition of ``Propulsion system''; and
0
iii. Add in alphabetical order definitions for ``Protection degree 
IPXXB'', ``Protection degree IPXXD'', ``Service disconnect'', and 
``Vehicle charge inlet'';
0
c. Revise S5.3 and S5.4; and
0
d. Add S5.4.1, S5.4.1.1, S5.4.1.1.1, S5.4.1.2, S5.4.1.3, S5.4.1.4, 
S5.4.2, S5.4.2.1, S5.4.2.2, S5.4.3, S5.4.3.1, S5.4.3.2, S5.4.3.3, 
S5.4.4, S5.4.5, S5.4.6, S5.4.6.1, S5.4.6.2, S5.4.6.3, S9, S9.1, S9.2, 
S9.3, and figures 6, 7a, 7b, and 8.
    The revisions and additions read as follows:

Sec.  571.305  Standard No. 305; Electric-powered vehicles: electrolyte 
spillage and electrical shock protection.

    S1. Scope. This standard specifies requirements for limitation of 
electrolyte spillage and retention of electric energy storage/
conversion devices during and after a crash, and protection from 
harmful electric shock during and after a crash and during normal 
vehicle operation.
    S2. Purpose. The purpose of this standard is to reduce deaths and 
injuries during and after a crash that occur because of electrolyte 
spillage from electric energy storage devices, intrusion of electric 
energy storage/conversion devices into the occupant compartment, and 
electrical shock, and to reduce deaths and injuries during

[[Page 12672]]

normal vehicle operation that occur because of electric shock.
* * * * *
    S4. Definitions.
* * * * *
    Charge connector is a conductive device that, by insertion into a 
vehicle charge inlet, establishes an electrical connection of the 
vehicle to the external electric power supply for the purpose of 
transferring energy and exchanging information.
    Direct contact is the contact of persons with high voltage live 
parts.
* * * * *
    Electrical protection barrier is the part providing protection 
against direct contact with live parts from any direction of access.
    Exposed conductive part is the conductive part that can be touched 
under the provisions of the IPXXB protection degree and becomes 
electrically energized under isolation failure conditions. This 
includes parts under a cover that can be removed without using tools.
    External electric power supply is a power supply external to the 
vehicle that provides electric power to charge the propulsion battery 
in the vehicle.
    Fuel cell system is a system containing the fuel cell stack(s), air 
processing system, fuel flow control system, exhaust system, thermal 
management system, and water management system.
* * * * *
    Indirect contact is the contact of persons with exposed conductive 
parts.
    Live part is a conductive part of the vehicle that is electrically 
energized under normal vehicle operation.
    Luggage compartment is the space in the vehicle for luggage 
accommodation, separated from the passenger compartment by the front or 
rear bulkhead and bounded by a roof, hood, floor, and side walls, as 
well as by the electrical barrier and enclosure provided for protecting 
the power train from direct contact with live parts.
    Passenger compartment is the space for occupant accommodation that 
is bounded by the roof, floor, side walls, doors, outside glazing, 
front bulkhead and rear bulkhead or rear gate, as well as electrical 
barriers and enclosures provided for protecting the occupants from 
direct contact with live parts.
    Possible active driving mode is the vehicle mode when application 
of pressure to the accelerator pedal (or activation of an equivalent 
control) or release of the brake system causes the electric power train 
to move the vehicle.
    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, and electronic 
controllers.
    Protection degree IPXXB is protection from contact with high 
voltage live parts. It is tested by probing electrical protection 
barriers or enclosures with the jointed test finger probe, IPXXB, in 
Figure 7b.
    Protection degree IPXXD is protection from contact with high 
voltage live parts. It is tested by probing electrical protection 
barriers or enclosures with the test wire probe, IPXXD, in Figure 7a.
    Service disconnect is the device for deactivation of an electrical 
circuit when conducting checks and services of the vehicle electrical 
propulsion system.
* * * * *
    Vehicle charge inlet is the device on the electric vehicle into 
which the charge connector is inserted for the purpose of transferring 
energy and exchanging information from an external electric power 
supply.
* * * * *
    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 paragraph S5.3(a) of this section, 
the voltage level requirements of paragraph S5.3(b) of this section, or 
the physical barrier protection requirements of paragraph S5.3(c) of 
this section.
    (a) The electrical isolation of the high voltage source, determined 
in accordance with the procedure specified in S7.6 of this section, 
must be greater than or equal to one of the following:
    (1) 500 ohms/volt for an AC high voltage source; or
    (2) 100 ohms/volt for an AC high voltage source if it is 
conductively connected to a DC high voltage source, but only if the AC 
high voltage source meets the physical barrier protection requirements 
specified in paragraph S5.3(c) of this section; or
    (3) 100 ohms/volt for a DC high voltage source.
    (b) The voltages V1, V2, and Vb of the high voltage source, 
measured according to the procedure specified in S7.7 of this section, 
must be less than or equal to 30 VAC for AC components or 60 VDC for DC 
components.
    (c) Protection against electric shock by direct and indirect 
contact (physical barrier protection) shall be demonstrated by meeting 
the following three conditions:
    (1) The high voltage source (AC or DC) meets the protection degree 
IPXXB when tested under the procedure specified in S9.1 of this section 
using the IPXXB test probe shown in Figures 7a and 7b to this section;
    (2) The resistance between exposed conductive parts of the 
electrical protection barriers and the electrical chassis is less than 
0.1 ohms when tested under the procedures specified in S9.2 of this 
section. In addition, the resistance between any two simultaneously 
reachable exposed conductive parts of the electrical protection 
barriers that are less than 2.5 meters from each other is less than 0.2 
ohms when tested under the procedures specified in S9.2 of this 
section; and
    (3) The voltages between the electrical protection barrier 
enclosing the high voltage source and other exposed conductive parts 
are less than or equal to 30 VAC or 60 VDC as measured in accordance 
with S9.3 of this section.
    S5.4 Electrical safety during normal vehicle operation.
    S5.4.1 Protection against direct contact.
    S5.4.1.1 Marking. The symbol shown in Figure 6 to this section 
shall be visible on or near electric energy storage/conversion devices. 
The symbol in Figure 6 to this section shall also be visible on 
electrical protection barriers which, when removed, expose live parts 
of high voltage sources. The symbol shall be yellow and the bordering 
and the arrow shall be black.
    S5.4.1.1.1 The marking is not required for electrical protection 
barriers that cannot be physically accessed, opened, or removed without 
the use of tools.
    S5.4.1.2 High voltage cables. Cables for high voltage sources which 
are not located within enclosures shall be identified by having an 
outer covering with the color orange.
    S5.4.1.3 Service disconnect. For a service disconnect which can be 
opened, disassembled, or removed without tools, protection degree IPXXB 
shall be provided when tested under procedures specified in S9.1 of 
this section using the IPXXB test probe shown in Figures 7a and 7b to 
this section.
    S5.4.1.4 Protection degree of high voltage sources and live parts.
    (a) Protection degree IPXXD shall be provided for live parts and 
high voltage sources inside the passenger or luggage compartment when 
tested under procedures specified in S9.1 of this section using the 
IPXXD test probe shown in Figure 7a to this section.
    (b) Protection degree IPXXB shall be provided for live parts and 
high voltage sources in areas other than the passenger or luggage 
compartment when

[[Page 12673]]

tested under procedures specified in S9.1 of this section using the 
IPXXB test probe shown in Figures 7a and 7b to this section.
    S5.4.2 Protection against indirect contact.
    S5.4.2.1 The resistance between all exposed conductive parts and 
the electrical chassis shall be less than 0.1 ohms when tested under 
the procedures specified in S9.2 of this section.
    S5.4.2.2 The resistance between any two simultaneously reachable 
exposed conductive parts of the electrical protection barriers that are 
less than 2.5 meters from each other shall not exceed 0.2 ohms when 
tested under the procedures specified in S9.2 of this section.
    S5.4.3 Electrical isolation.
    S5.4.3.1 Electrical isolation of AC and DC high voltage sources. 
The electrical isolation of a high voltage source, determined in 
accordance with the procedure specified in S7.6 of this section must be 
greater than or equal to one of the following:
    (a) 500 ohms/volt for an AC high voltage source;
    (b) 100 ohms/volt for an AC high voltage source if it is 
conductively connected to a DC high voltage source, but only if the AC 
high voltage source meets the requirements for protection against 
direct contact in S5.4.1.4 of this section and the protection from 
indirect contact in S5.4.2 of this section; or
    (c) 100 ohms/volt for a DC high voltage source.
    S5.4.3.2 Exclusion of high voltage sources from electrical 
isolation requirements. A high voltage source that is conductively 
connected to an electric energy storage device which is conductively 
connected to the electrical chassis and has a working voltage less than 
or equal to 60 VDC, is not required to meet the electrical isolation 
requirements in S5.4.3.1 of this section during normal vehicle 
operating conditions if the voltage between the high voltage source and 
the electrical chassis is less than or equal to 30 VAC or 60 VDC.
    S5.4.3.3 Isolation resistance of high voltage sources for charging 
the electric energy storage device. For motor vehicles with an electric 
energy storage device that can be charged through a conductive 
connection with the grounded external electric power supply, the 
isolation resistance between the electrical chassis and the vehicle 
charge inlet and each high voltage source conductively connected to the 
vehicle charge inlet during charging of the electric energy storage 
device shall be a minimum of one million ohms when the charge connector 
is disconnected. The isolation resistance is determined in accordance 
with the procedure specified in S7.6 of this section.
    S5.4.4 Electrical isolation monitoring. Each DC high voltage 
sources of vehicles with a fuel cell system shall be monitored by an 
electrical isolation monitoring system that displays a warning for loss 
of isolation when tested according to S8 of this section. The system 
must monitor its own readiness and the warning display must be visible 
to the driver seated in the driver's designated seating position.
    S5.4.5 Electric shock protection during charging. For motor 
vehicles with an electric energy storage device that can be charged 
through a conductive connection with a grounded external electric power 
supply, a device to enable conductive connection of the electrical 
chassis to the earth ground shall be provided. This device shall enable 
connection to the earth ground before exterior voltage is applied to 
the vehicle and retain the connection until after the exterior voltage 
is removed from the vehicle.
    S5.4.6 Mitigating driver error.
    S5.4.6.1 Indicator of possible active driving mode at start up. At 
least a momentary indication shall be given to the driver when the 
vehicle is in possible active driving mode. This requirement does not 
apply under conditions where an internal combustion engine provides 
directly or indirectly the vehicle's propulsion power upon start up.
    S5.4.6.2 Indicator of possible active driving mode when leaving the 
vehicle. When leaving the vehicle, the driver shall be informed by an 
audible or visual signal if the vehicle is still in the possible active 
driving mode.
    S5.4.6.3 Prevent drive-away during charging. If the on-board 
electric energy storage device can be externally charged, vehicle 
movement by its own propulsion system shall not be possible as long as 
the charge connector of the external electric power supply is 
physically connected to the vehicle charge inlet.
* * * * *
    S9 Test methods for physical barrier protection from electric shock 
due to direct and indirect contact with high voltage sources.
    S9.1 Test method to evaluate protection from direct contact with 
high voltage sources.
    (a) Any parts surrounding the high voltage components are opened, 
disassembled, or removed without the use of tools.
    (b) The selected access probe is inserted into any gaps or openings 
of the electrical protection barrier with a test force of 10 N  1 N with the IPXXB probe or 1 to 2 N with the IPXXD probe. If 
partial or full penetration into the physical barrier occurs, the probe 
shall be placed as follows: Starting from the straight position, both 
joints of the test finger are rotated progressively through an angle of 
up to 90 degrees with respect to the axis of the adjoining section of 
the test finger and are placed in every possible position.
    (c) A low voltage supply (of not less than 40 V and not more than 
50 V) in series with a suitable lamp may be connected between the 
access probe and any high voltage live parts inside the physical 
barrier to indicate whether live parts were contacted.
    (d) A mirror or fiberscope may be used to inspect whether the 
access probe touches high voltage parts inside the physical barrier.
    S9.2 Test method to evaluate protection against indirect contact 
with high voltage sources.
    (a) Test method using a resistance tester. The resistance tester is 
connected to the measuring points (the electrical chassis and any 
exposed conductive part of the vehicle or any two exposed conductive 
parts that are less than 2.5 meters from each other), and the 
resistance is measured using a resistance tester that can measure 
current levels of at least 0.1 Amperes with a resolution of 0.01 ohms 
or less.
    (b) Test method using a DC power supply, voltmeter and ammeter.
    (1) Connect the DC power supply, voltmeter and ammeter to the 
measuring points (the electrical chassis and any exposed conductive 
part or any two exposed conductive parts that are less than 2.5 meters 
from each other) as shown in Figure 8 to this section.
    (2) Adjust the voltage of the DC power supply so that the current 
flow becomes more than 0.2 Amperes.
    (3) Measure the current I and the voltage V shown in Figure 8 to 
this section.
    (4) Calculate the resistance R according to the formula, R=V/I.
    S9.3 Test method to determine voltage between electrical protection 
barrier and exposed conductive parts, including electrical chassis, of 
the vehicle.
    (a) Connect the DC power supply and voltmeter to the measuring 
points (exposed conductive part of an electrical protection barrier and 
the electrical chassis or any other exposed conductive part of the 
vehicle).
    (b) Measure the voltage.

[[Page 12674]]

    (c) After completing the voltage measurements for all electrical 
protection barriers, the voltage differences between all exposed 
conductive parts of the protective barriers shall be calculated.
* * * * *
BILLING CODE 4910-59-P
[GRAPHIC] [TIFF OMITTED] TP10MR16.009

[GRAPHIC] [TIFF OMITTED] TP10MR16.010

[[Page 12675]]

[GRAPHIC] [TIFF OMITTED] TP10MR16.011

[[Page 12676]]

[GRAPHIC] [TIFF OMITTED] TP10MR16.012

Raymond R. Posten,
Associate Administrator for Rulemaking.
[FR Doc. 2016-05187 Filed 3-9-16; 8:45 am]
 BILLING CODE 4910-59-C