ISO 6469-4:2015

Electrically propelled road vehicles - Safety specifications - Part 4: Post crash electrical safety

ISO 6469-4:2015 specifies safety requirements for the electric propulsion systems and conductively connected auxiliary electric systems of electrically propelled road vehicles for the protection of persons inside and outside the vehicle. It specifies electrical safety requirements for vehicle post-crash conditions. It applies to electrically propelled road vehicles with voltage class B electric circuits. It does not apply to motorcycles and mopeds. It does not specify any crash test procedure. The safety requirements of this part of ISO 6469-4:2015 apply to applicable vehicles in accordance with published crash test procedures of each country or region. Applicable vehicles are those vehicles which are explicitly specified in these crash test procedures. It does not provide comprehensive safety information for first responders, emergency services, maintenance, and repair personnel.

Véhicules routiers électriques — Spécifications de sécurité — Partie 4: Exigences de sécurité électrique après accident

General Information

• Status: Published
• Publication Date: 31-Aug-2015
• ICS: 43.120 - Electric road vehicles
• Technical Committee: ISO/TC 22/SC 37 - Electrically propelled vehicles
• Drafting Committee: ISO/TC 22/SC 37 - Electrically propelled vehicles
• Parallel Committee: ISO/TC 43/SC 1 - Noise
• Current Stage: 9092 - International Standard to be revised
• Start Date: 06-Dec-2024
• Completion Date: 13-Dec-2025

Overview

ISO 6469-4:2015 - Electrically propelled road vehicles - Safety specifications - Part 4: Post crash electrical safety - defines electrical safety requirements for electrically propelled road vehicles after a crash. It focuses on protection of persons inside and outside the vehicle by specifying post‑crash limits and tests for voltage class B electric circuits (>(30 V and ≤1 000 V) a.c. or >(60 V and ≤1 500 V) d.c.). The standard applies to full electric and hybrid road vehicles (excludes motorcycles and mopeds), but it does not prescribe crash test procedures - it is applied in accordance with published regional crash test protocols. It also clarifies that it is not a comprehensive manual for first responders or repair personnel.

Key Topics and Requirements

• Post‑crash electrical safety criteria: After a crash, at least one protection criterion must be met for each voltage class B circuit (voltage limit, isolation resistance, physical protection, or electrical energy limit).
• Voltage limit: Voltage must be ≤30 V a.c. (rms) or ≤60 V d.c. at a defined time point after impact (either 10 s after initial impact if vehicle stops within 5 s, or 5 s after the vehicle comes to rest).
• Isolation resistance: Minimum isolation resistance values are specified per voltage class and circuit type:
  • Separated a.c. and d.c.: 500 Ω/V for a.c., 100 Ω/V for d.c.
  • Combined circuits: multiple compliance options (e.g., 500 Ω/V overall or 100 Ω/V plus additional protections).
• Physical protection (IPXXB): Protection against direct contact with live parts using enclosure/barrier requirements per ISO 20653; includes potential equalisation and low resistance bonding paths.
• Electrical energy limits & capacitors: Limits on stored energy (including Y‑ and X‑capacitors) to reduce shock risk; special attention to potential body currents from Y‑capacitors.
• RESS electrolyte spillage: Requirements and test procedures addressing battery electrolyte leakage post‑crash.
• Testing guidance: Test setup, conditions and procedures are detailed for verifying voltage limit, isolation resistance, physical protection and energy limits.

Applications and Users

ISO 6469-4:2015 is used by:

• Automotive OEMs and design engineers for post‑crash electrical safety design and validation.
• Safety and compliance teams during vehicle homologation and certification.
• Test laboratories performing electrical safety verification following regional crash tests.
• Regulators and standardization bodies integrating post‑crash electrical criteria into vehicle safety regulations.

Note: emergency services should consult dedicated responder guidance - this standard is not a substitute for first‑responder protocols.

Related Standards

• ISO 6469‑1: On‑board rechargeable energy storage system (RESS)
• ISO 6469‑2: Vehicle operational safety means and protection against failures
• ISO 6469‑3: Protection of persons against electric shock
• ISO 20653: Degrees of protection (IP code) for road vehicle electrical equipment
• ISO/TR 8713: Vocabulary for electrically propelled road vehicles

Keywords: ISO 6469-4:2015, post crash electrical safety, electrically propelled road vehicles, voltage class B, isolation resistance, IPXXB, RESS electrolyte spillage, electric shock protection.

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 6469-4
First edition
2015-09-01
Electrically propelled road vehicles —
Safety specifications —
Part 4:
Post crash electrical safety
Véhicules routiers électriques — Spécifications de sécurité —
Partie 4: Exigences de sécurité électrique après accident
Reference number
©
ISO 2015
© ISO 2015, Published in Switzerland
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form
or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior
written permission. Permission can be requested from either ISO at the address below or ISO’s member body in the country of
the requester.
ISO copyright office
Ch. de Blandonnet 8 • CP 401
CH-1214 Vernier, Geneva, Switzerland
Tel. [phone]
Fax [phone]
[e-mail]
www.iso.org
ii © ISO 2015 – All rights reserved

Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Applied crash test procedures . 3
5 Electric safety requirements . 3
5.1 General . 3
5.2 Protection against electric shock . 3
5.2.1 General. 3
5.2.2 Voltage limit . 4
5.2.3 Isolation resistance . 4
5.2.4 Physical protection . 4
5.2.5 Electrical energy limit . 5
5.3 Protection against overcurrent . 5
6 RESS electrolyte spillage . 5
7 Testing . 6
7.1 Test conditions . 6
7.1.1 General. 6
7.1.2 Preparation of vehicle or test configuration . 6
7.2 Test procedures for electrical safety . 6
7.2.1 Test setup and equipment . 6
7.2.2 Voltage limit . 7
7.2.3 Isolation resistance . 7
7.2.4 Physical protection .10
7.2.5 Electrical energy limit .11
7.3 Test procedure for RESS electrolyte spillage .13
8 Supplementary information .14
Bibliography .15
Foreword
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described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
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For an explanation on the meaning of ISO specific terms and expressions related to conformity
assessment, as well as information about ISO’s adherence to the WTO principles in the Technical
Barriers to Trade (TBT) see the following URL: Foreword - Supplementary information
The committee responsible for this document is ISO/TC 22, Road vehicles, Subcommittee SC 21,
Electrically propelled road vehicles.
ISO 6469 consists of the following parts, under the general title Electrically propelled road vehicles —
Safety specifications:
— Part 1: On-board rechargeable energy storage system (RESS)
— Part 2: Vehicle operational safety means and protection against failures
— Part 3: Protection of persons against electric shock
— Part 4: Post crash electrical safety
iv © ISO 2015 – All rights reserved

INTERNATIONAL STANDARD ISO 6469-4:2015(E)
Electrically propelled road vehicles — Safety
specifications —
Part 4:
Post crash electrical safety
1 Scope
This part of ISO 6469 specifies safety requirements for the electric propulsion systems and conductively
connected auxiliary electric systems of electrically propelled road vehicles for the protection of persons
inside and outside the vehicle. It specifies electrical safety requirements for vehicle post-crash conditions.
It applies to electrically propelled road vehicles with voltage class B electric circuits.
It does not apply to motorcycles and mopeds.
It does not specify any crash test procedure. The safety requirements of this part of ISO 6469 apply
to applicable vehicles in accordance with published crash test procedures of each country or region.
Applicable vehicles are those vehicles which are explicitly specified in these crash test procedures.
It does not provide comprehensive safety information for first responders, emergency services,
maintenance, and repair personnel.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
ISO 6469-3, Electrically propelled road vehicles — Safety specifications — Part 3: Protection of persons
against electric shock
ISO 20653, Road vehicles — Degrees of protection (IP code) — Protection of electrical equipment against
foreign objects, water and access
ISO/TR 8713, Electrically propelled road vehicles — Vocabulary
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO/TR 8713 and the following apply.
3.1
auxiliary electric system
on-board vehicle system, other than the propulsion system, which operates on electric energy
3.2
barrier
part providing protection against direct contact from any usual direction of access
3.3
conductive part
part capable of conducting electric current
3.4
direct contact
contact of persons with live parts
3.5
electric chassis
conductive parts of a vehicle that are electrically connected and whose potential is taken as reference
3.6
electric drive
combination of traction motor, power electronics, and their associated controls for the conversion of
electric to mechanical power and vice versa
3.7
electric shock
physiological effect resulting from an electric current passing through a human body
3.8
electrically propelled vehicle
vehicle with at least one electric drive for vehicle propulsion
3.9
enclosure
part providing protection of equipment against direct contact from any direction
3.10
exposed conductive part
conductive part of the electric equipment, that can be touched by a test finger according to IPXXB (see
ISO 20653) after removing barriers/enclosures that can be removed without using tools and that is not
normally live, but which may become live under fault conditions
3.11
isolation resistance
resistance between live parts of voltage class B electric circuit and the electric chassis as well as the
voltage class A system
3.12
line conductor
conductor which is electrically energized in normal operation and capable of contributing to the
transmission or distribution of electric energy
3.13
live part
conductor or conductive part intended to be electrically energized in normal operation
3.14
maximum working voltage
highest value of a.c. voltage (rms) or of d.c. voltage which may occur in an electric system under any
normal operating conditions according to manufacturer’s specifications, disregarding transients
3.15
potential equalisation
electric connections of exposed conductive parts of the electric equipment to minimize differences in
potential between these parts
3.16
rechargeable energy storage system
RESS
system that stores energy for delivery of electric energy for vehicle propulsion and which is rechargeable
EXAMPLE Battery, capacitors.
2 © ISO 2015 – All rights reserved

3.17
voltage class A
classification of an electric component or circuit with a maximum working voltage of ≤30 V a.c. (rms) or
≤60 V d.c. respectively
3.18
voltage class B
classification of an electric component or circuit with a maximum working voltage of (>30 and
≤1 000) V a.c. (rms) or (>60 and ≤1 500) V d.c. respectively
3.19
X-capacitors
capacitors located between line conductors of different polarity
3.20
Y-capacitors
capacitors located between line conductor and electric chassis
4 Applied crash test procedures
The safety requirements of this part of ISO 6469 shall apply in accordance with the published crash test
procedures of a country or region for vehicles or test configurations which are explicitly specified in
these crash test procedures.
5 Electric safety requirements
5.1 General
The following requirements shall be fulfilled after a vehicle crash test or after a crash test with a test
configuration according to 4.
NOTE Retention of voltage class B components, e.g. RESS, is not covered in this part of ISO 6469 because it is
not relevant for electrical safety.
5.2 Protection against electric shock
5.2.1 General
After the crash test at least one of the criteria specified in 5.2.2 through 5.2.5 shall be met for each
voltage class B electric circuit. This includes all voltage class B electric circuits which are disconnected
or electrically separated in post-crash situations. For different parts of a circuit, different criteria
specified in 5.2.2 through 5.2.5 may apply.
If the test is performed under the condition that part(s) of the voltage class B electric circuits are
not electrically energized because of specific crash test conditions different from normal operation,
the protection against electric shock shall be proved by either 5.2.3 or 5.2.4 for the relevant part(s).
Examples for such specific test conditions are as follows:
— fuel cell vehicle crash test performed with alternative fuel;
— crash test performed with energy sources disconnected prior to the crash test.
NOTE Electronic switches can be used for disconnection.
5.2.2 Voltage limit
The voltages V , V , and V (see Figure 1) of the voltage class B electric circuits shall be equal to or less
b 1 2
than 30 V a.c. (rms) or 60 V d.c. at a point in time t which is specified as
m
— either 10 s after the initial impact, if the vehicle comes to rest within 5 s after the initial impact, or
— 5 s after the vehicle comes to rest, if the vehicle does not come to rest within 5 s after the initial impact.
Compliance shall be tested in accordance with 7.2.2.
5.2.3 Isolation resistance
5.2.3.1 General
The isolation resistance shall fulfil the requirements according to 5.2.3.2 and 5.2.3.3.
If direct contact to one potential of the voltage class B electric circuit is possible, the energy in
Y-capacitors, TE , as calculated in 7.2.5.2.2 shall be less than 0,2 J.
y
NOTE A potential body current caused by Y-capacitors is not limited by isolation resistance.
The isolation resistance criterion shall not apply if direct contact to more than one single potential
of a part of the voltage class B electric circuit is possible; see 5.2.4 (physical protection). However,
isolation resistance criterion is applicable if the voltage difference between those accessible live parts
meets the voltage limit specified in 5.2.2 or the potential energy between them meets the energy limit
specified in 5.2.5.
Compliance shall be tested in accordance with 7.2.3.
If test procedures include a static rollover test after a crash, evaluation of isolation resistance can be
conducted before, during, and/or after the rollover test.
5.2.3.2 Separated d.c. and a.c. voltage class B electric circuits
If the a.c. voltage class B electric circuits and the d.c. voltage class B electric circuits are not conductively
connected to each other, isolation resistance, divided by the maximum working voltage, shall have a
minimum value of 100 Ω/V for d.c. circuits, and a minimum value of 500 Ω/V for a.c. circuits.
5.2.3.3 Combined d.c. and a.c. voltage class B electric circuits
If the a.c. voltage class B electric circuits and the d.c. voltage class B electric circuits are conductively
connected, they shall meet one of the following requirements:
a) isolation resistance, divided by the maximum working voltage, shall have a minimum value of
500 Ω/V;
b) isolation resistance, divided by the maximum working voltage, shall have a minimum value of
100 Ω/V and the a.c. circuit meets the physical protection as described in 5.2.4;
c) isolation resistance, divided by the maximum working voltage, shall have a minimum value of
100 Ω/V and the a.c. circuit meets the voltage limit as described in 5.2.2;
d) isolation resistance, divided by the maximum working voltage, shall have a minimum value of
100 Ω/V and the a.c. circuit meets the electrical energy limit as specified in 5.2.5.
5.2.4 Physical protection
For protection against direct contact with voltage class B live parts, the protection degree IPXXB in
accordance with ISO 20653 shall be provided. Compliance shall be tested in accordance with 7.2.4.1.
4 © ISO 2015 – All rights reserved

In addition, one of the following requirements [a) or b)] shall be fulfilled:
a) The potential equalisation paths intended by design shall be clarified in advance in accordance
with the manufacturer’s specification, e.g. using diagrams, etc. The potential equalisation paths
intended by design are the relevant electric connections or potential equalisation in accordance
with ISO 6469-3 for the vehicle as built. The resistance between all exposed conductive parts and
the electric chassis shall be less than or equal to 0,1 Ω. This requirement is deemed to be satisfied if
the connection is established and maintained by welding. Compliance shall be tested in accordance
with 7.2.4.2.
In addition, one of the following requirements shall be fulfilled.
— A short circuit current, if any, shall be interrupted.
— The isolation resistance divided by the maximum working voltage shall be ≥0,01 Ω/V for d.c.
circuits or 0,05 Ω/V for a.c. circuits. This requirement is deemed to be satisfied if the system
meets isolation requirements in 5.2.3. Compliance shall be tested in accordance with 7.2.4.3.
b) At t (see 5.2.2), the voltage between any two exposed conductive parts that can be touched
m
simultaneously by a person shall be equal to or less than 30 V a.c. or 60 V d.c. Compliance shall be
tested in accordance with 7.2.4.4.
NOTE For overcurrent protection see 5.3.
If test procedures include a rollover test after crash, evaluation of physical protection shall be conducted
after and might be additionally conducted before the rollover test.
5.2.5 Electrical energy limit
At t (see
...