ISO 6469-3:2018

INTERNATIONAL ISO
STANDARD 6469-3
Third edition
2018-10
Electrically propelled road vehicles —
Safety specifications —
Part 3:
Electrical safety
Véhicules routiers électriques — Spécifications de sécurité —
Partie 3: Sécurité électrique
Reference number
ISO 6469-3:2018(E)
©
ISO 2018

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ISO 6469-3:2018(E)

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ISO 6469-3:2018(E)

Contents Page
Foreword .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Voltage classes . 6
5 General requirements . 6
5.1 Environmental and operational requirements . 6
5.2 Marking . 6
5.2.1 Marking of voltage class B electric components. 6
5.2.2 Marking of voltage class B wiring . 7
6 Requirements for protection of persons against electric shock . 7
6.1 General requirements . 7
6.1.1 General requirements for connected sections of a circuit . 7
6.1.2 General requirements for voltage class B1 . 7
6.1.3 General requirements for voltage class B2 . 8
6.2 Basic protection . 8
6.3 Fault protection and additional measures . 8
6.3.1 Equipotential bonding . 8
6.3.2 Isolation resistance . 8
6.3.3 Provisions for capacitive coupling and capacitive discharge .10
6.3.4 De-energization .10
6.3.5 Alternative protection measures .11
6.4 General requirements for protective provisions .11
6.4.1 General.11
6.4.2 Requirements for insulation .11
6.4.3 Requirements for protective barriers and protective enclosures .11
6.4.4 Requirements for connectors .12
6.4.5 Insulation Coordination .12
6.5 Alternative approach for protection against electric shock .12
7 Protection against thermal incidents .13
7.1 Overload protection .13
7.2 Short-circuit protection .13
8 Requirements for vehicle power supply circuit .13
9 Owner's manual .13
10 Test procedures .13
10.1 General .13
10.2 Continuity test for equipotential bonding .13
10.3 Isolation resistance measurements for voltage class B2 electric circuits .14
10.3.1 Preconditioning and conditioning .14
10.3.2 Isolation resistance measurements of the balance of electric circuits .14
10.3.3 Isolation resistance measurement of the voltage class B2 electric power
sources .15
10.3.4 Isolation resistance measurement of entire electric circuits .17
10.4 Test for isolation resistance monitoring system .17
10.5 Touch current .17
10.6 Withstand voltage test .18
10.6.1 General.18
10.6.2 Preconditioning and conditioning .18
10.6.3 Test procedure .19
10.6.4 Test criteria .19
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ISO 6469-3:2018(E)

Bibliography .20
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ISO 6469-3:2018(E)

Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
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
editorial rules of the ISO/IEC Directives, Part 2. www .iso .org/directives
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received. www .iso .org/patents
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation on the voluntary nature of standards, 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.
This document was prepared by Technical Committee ISO/TC 22 Road vehicles, Subcommittee SC 37,
Electrically propelled vehicles.
This third edition cancels and replaces the second edition (ISO 6469-3:2011), which has been technically
revised.
The main changes compared to the previous edition are as follows:
— extension of pure electric shock protection to all electric safety requirements including those
against thermal incidents;
— introduction of definitions and requirements for new voltage classes B1 and B2;
— addition of specific requirements for capacitive discharge;
— new test specification for the isolation resistance monitoring system; and
— new requirements and test for touch current.
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INTERNATIONAL STANDARD ISO 6469-3:2018(E)
Electrically propelled road vehicles — Safety
specifications —
Part 3:
Electrical safety
IMPORTANT — The electronic file of this document contains colours which are considered to be
useful for the correct understanding of the document. Users should therefore consider printing
this document using a colour printer.
1 Scope
This document specifies electrical safety requirements for voltage class B electric circuits of electric
propulsion systems and conductively connected auxiliary electric systems of electrically propelled
road vehicles.
It specifies electrical safety requirements for protection of persons against electric shock and thermal
incidents.
It does not provide comprehensive safety information for manufacturing, maintenance and repair
personnel.
NOTE 1 Electrical safety requirements for post-crash are described in ISO 6469-4.
NOTE 2 Electrical safety requirements for conductive connections of electrically propelled road vehicles to an
external electric power supply are described in ISO 17409.
NOTE 3 Specific electrical safety requirements for magnetic field wireless power transfer between an external
electric power supply and an electrically propelled vehicle are described in ISO PAS 19363.
NOTE 4 Electrical safety requirements for motorcycles and mopeds are described in ISO 13063.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 7010, Graphical symbols — Safety colours and safety signs — Registered safety signs
ISO 17409, Electrically propelled road vehicles — Connection to an external electric power supply — Safety
requirements
ISO 20653, Road vehicles — Degrees of protection (IP code) — Protection of electrical equipment against
foreign objects, water and access
IEC 60664 (all parts), Insulation coordination for equipment within low-voltage systems
IEC 60950-1, Information technology equipment — Safety — Part 1: General requirements
IEC 60990:2016, Methods of measurement of touch current and protective conductor current
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ISO 6469-3:2018(E)

3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— IEC Electropedia: available at http: //www .electropedia .org/
— ISO Online browsing platform: available at https: //www .iso .org/obp
3.1
auxiliary electric system
vehicle system, other than the propulsion system, that operates on electric energy
3.2
balance of electric circuit
remaining section of an electric circuit when all electric power sources that are energized (e.g. RESS
(3.31) and fuel cell stacks (3.20)) are disconnected
3.3
basic insulation
insulation of hazardous live parts (3.22) which provides basic protection (3.4)
Note 1 to entry: This concept does not apply to insulation used exclusively for functional purposes.
Note 2 to entry: Where insulation is not provided by solid insulation only, it is complemented with protective
barriers or protective enclosures to prevent access to live parts in order to achieve basic protection.
[SOURCE: IEC 60050-195:1998, 195-06-06, modified — “hazardous-live-parts” written as “hazardous
live parts”, Note 2 to entry added]
3.4
basic protection
protection against electric shock (3.14) under fault-free conditions
[SOURCE: IEC 60050-195:1998, 195-06-01]
3.5
clearance
shortest distance in air between two conductive parts (3.6)
[SOURCE: IEC 60664-1:2007, 3.2]
3.6
conductive part
part which can carry electric current
[SOURCE: IEC 60050-195:1998, 195-01-06]
3.7
conductively connected circuit
two electric circuits are considered conductively connected unless they are separated by at least basic
insulation
3.8
creepage distance
shortest distance along the surface of a solid insulating material between two conductive parts (3.6)
[SOURCE: IEC 60050-151:2001/AMD1: 2013, 151-15-50]
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ISO 6469-3:2018(E)

3.9
degree of protection
IP
protection provided by an enclosure or barriers against access, foreign objects and/or water and
verified by standardized test methods in accordance with ISO 20653
[SOURCE: ISO 20653, modified — “in accordance with ISO 20653” added]
3.10
direct contact
electric contact of persons or animals with live parts (3.25)
[SOURCE: IEC 60050-195:1998, 195-06-03]
3.11
double insulation
insulation comprising both basic insulation (3.3) and supplementary insulation (3.33)
[SOURCE: IEC 60050-195:1998, 195-06-08]
3.12
electric chassis
conductive parts (3.6) of a vehicle that are electrically connected and whose potential is taken as
reference
3.13
electric drive
combination of traction motor, power electronics and their associated controls for the conversion of
electric to mechanical power and vice versa
3.14
electric shock
physiological effect resulting from an electric current through a human body or animal body
[SOURCE: IEC 60050-195:1998, 195-01-04]
3.15
electrically propelled vehicle
vehicle with one or more electric drive(s) (3.13) for vehicle propulsion
3.16
energized
qualifies a conductive part having an electric potential difference with respect to a relevant reference
[SOURCE: IEC 60050-151:2001/AMD1: 2013, 151-15-58, modified — Note deleted]
3.17
equipotential bonding
provision of electric connections between conductive parts (3.6), intended to achieve equipotentiality
[SOURCE: IEC 60050-195:1998, 195-01-10]
3.18
exposed conductive part
conductive part (3.6) of equipment which can be touched and which is not normally live, but which can
become live when basic insulation (3.3) fails
Note 1 to entry: A conductive part of electrical equipment which can become live only through contact with an
exposed conductive part which has become live, is not considered to be an exposed conductive part itself.
[SOURCE: IEC 61140:2016, 3.6, modified — “exposed conductive part” replaces “exposed-conductive-
part” and Note 1 to entry deleted]
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ISO 6469-3:2018(E)

3.19
fault protection
protection against electric shock (3.14) under single-fault conditions
[SOURCE: IEC 60050-195:1998, 195-06-02]
3.20
fuel cell stack
assembly of two or more fuel cells that are electrically connected
3.21
fuel cell system
system, typically containing the following subsystems: fuel cell stack (3.20), air processing, fuel
processing, thermal management, water management, and their control
3.22
hazardous live part
live part (3.25) which, under certain conditions, can give a harmful electric shock
Note 1 to entry: For guidance on harmful physiological effects see IEC 61140.
[SOURCE: IEC 60050-195:1995, 448-14-31, modified — term changed from “hazardous-live-part” to
“hazardous live part” and Note 1 to entry added]
3.23
isolation resistance
insulation resistance
resistance between live parts (3.25) of an electric circuit and the electric chassis (3.12) as well as other
electric circuits which are insulated from this electric circuit
3.24
isolation resistance monitoring system
system that periodically or continuously monitors the isolation resistance (3.23) between live parts
(3.25) and the electric chassis (3.12)
3.25
live part
conductor or conductive part (3.6) intended to be energized in normal use, but by convention not the
electric chassis (3.12)
[SOURCE: IEC 60050-195:1998, 195-02-19, modified — “including a neutral conductor” and Note 1 to
entry deleted and "a PEN conductor or PEM conductor or PEL conductor" replaced by "the electric
chassis"]
3.26
maximum working voltage
highest value of AC voltage (rms) or of DC voltage that can occur under any normal operating conditions
according to the manufacturer's specifications, disregarding transients and ripple
3.27
overload protection
protection intended to operate in the event of overload on the protected section
[SOURCE: IEC 60050-448:1995, 448-14-31]
3.28
overcurrent protection
protection intended to operate when the current is in excess of a predetermined value
[SOURCE: IEC 60050-448:1995, 448-14-26]
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ISO 6469-3:2018(E)

3.29
protective barrier
part providing protection against direct contact (3.10) from any usual direction of access
[SOURCE: IEC 60050-195:1998, 195-06-15, modified — optional prefix “(electrically)” removed]
3.30
protective enclosure
electrical enclosure surrounding internal parts of equipment to prevent access to hazardous live parts
(3.22) from any direction
[SOURCE: IEC 60050-195:1998, 195-06-14, modified — optional prefix “(electrically)” removed and
“hazardous-live-parts” written as “hazardous live parts”]
3.31
rechargeable energy storage system
RESS
rechargeable system that stores energy for delivery of electric energy for the electric drive (3.13)
EXAMPLE Battery, capacitor, flywheel.
3.32
reinforced insulation
insulation of hazardous live parts (3.22) which provides protection against electric shock (3.14)
equivalent to double insulation (3.11)
Note 1 to entry: Reinforced insulation may comprise several layers that cannot be tested singly as basic insulation
or supplementary insulation.
[SOURCE: IEC 61140:2016, 3.10.4]
3.33
supplementary insulation
independent insulation applied in addition to basic insulation (3.3), for fault protection
[SOURCE: IEC 60050-195:1998, 195-06-07]
3.34
touch current
electric current passing through a human body or through livestock when it touches one or more
accessible parts of cables or equipment
[SOURCE: ISO 17409:2017, 3.42, modified — “cables” replaces “an electrical installation”]
3.35
vehicle power supply circuit
voltage class (3.36) B electric circuit which includes all parts that are conductively connected to the
vehicle inlet (case B, case C) or the plug (case A) or part of an Autoconnect Charging Device that is
mounted on the electrically propelled vehicle (case D, case E) and that is operational when connected to
an external electric power supply
Note 1 to entry: Case A, case B, case C are defined in IEC 61851-1.
Note 2 to entry: Case D, case E and Autoconnect Charging Device are defined in IEC 61851-23-1 (under
preparation).
[SOURCE: ISO 17409:2017, 3.47, modified — “conductively” replaces “galvanically”]
3.36
voltage class
classification of an electric component or circuit according to its maximum working voltage (3.26)
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ISO 6469-3:2018(E)

4 Voltage classes
Depending on its maximum working voltage U, an electric circuit, a section of a circuit or an electric
component belongs to the voltage classes specified in Table 1.
Table 1 — Voltage classes
Maximum working voltage
Voltage class
DC in V AC in V (rms value)
A 0 < U ≤ 60 0 < U ≤ 30
B 60 < U ≤ 1 500 30 < U ≤ 1 000
B1 60 < U ≤ 75 30 < U ≤ 50
B2 75 < U ≤ 1 500 50 < U ≤ 1 000
The voltage classes B1 and B2 are subclasses of voltage class B. Due to the different voltage levels,
different requirements are specified for voltage class B1 and voltage class B2, whereas the requirements
for voltage class B2 are more stringent. The requirements for voltage class B2 may be applied for the
complete range of voltage class B, including the voltage range of voltage class B1. It is allowed to use
voltage class B instead of voltage class B1 and voltage class B2.
In cases where voltage class B is referenced by another standard, the requirements for voltage
class B2 apply.
NOTE 1 Dividing voltage class B into two voltage classes B1 and B2 allows chassis connected voltage class
B1 drivetrain and connected electrical systems in electric vehicles according to the given scope. Otherwise,
all circuits which contain AC sections with a maximum working voltage between 30 V AC and 50 V AC, and DC
sections with a maximum working voltage up to 60 V DC, would have to be insulated from the chassis, only
because the AC part of the circuit falls into voltage class B range, whereas the DC part could still fall under the
regulations for a voltage class A circuit.
NOTE 2 If the requirements of voltage class B1 are fulfilled, the maximum working voltage of an electric
circuit, a section of a circuit or an electric component can be up to 75 V DC and up to 50 V AC.
NOTE 3 The requirements for voltage class B1 are based on IEC 61140, IEC 60479-1, IEC 60479-2, IEC 60479-5,
and IEC 60364-4-41.
NOTE 4 The voltage limits of voltage class B1 are harmonized with the European Low Voltage Directive and
IEC 61140 (the AC limit). Electric vehicles are not in the scope of the European Low Voltage Directive.
5 General requirements
5.1 Environmental and operational requirements
The requirements given in this document shall be met across the range of environmental and
operational conditions for which the electrically propelled vehicle is designed to operate, as specified
by the vehicle manufacturer.
NOTE See ISO 16750, ISO PAS 19295 and ISO 19453 for guidance.
5.2 Marking
5.2.1 Marking of voltage class B electric components
The symbol W012 in accordance with ISO 7010 shown in Figure 1 shall be visible on protective barriers
and protective enclosures, which, when removed, expose hazardous live parts of voltage class B electric
circuits. Accessibility and removability of protective barriers and protective enclosures should be
considered when evaluating the requirement for the symbol.
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ISO 6469-3:2018(E)

The symbol may be embossed or engraved in accordance with Figure 1. In this case colour is not
required.
For a protective enclosure consisting of several parts, one symbol is sufficient when visibility of the
symbol is given.
Figure 1 — Symbol W 012
5.2.2 Marking of voltage class B wiring
The outer covering of cables and harness for voltage class B2 electric circuits not within protective
enclosures or behind protective barriers shall be marked with orange colour. Voltage class B1 cables
and harness shall be marked with a two-colour combination of orange and purple or with orange colour.
In case of the two colour combination, each colour shall cover at least 30 % of the surface. The marking
shall be visible over the whole cable length and from all usual directions of access.
Voltage class B connectors may be identified by the harnesses to which the connector is attached.
NOTE Specifications of the orange colour are given e.g. in standards in the US (8.75R5.75/12.5) and in Japan
(8.8R5.8/12.5) according to the Munsell colour system.
6 Requirements for protection of persons against electric shock
6.1 General requirements
6.1.1 General requirements for connected sections of a circuit
If not specified otherwise, an electric circuit consisting of conductively connected sections with
different maximum working voltages shall be classified according to the highest maximum working
voltage.
6.1.2 General requirements for voltage class B1
Protection against electric shock for voltage class B1 shall be comprised of:
— limitation of voltage in accordance with Table 1;
— provisions for basic protection according to 6.2; and
— additional measures according to 6.3.1 and 6.3.3.
The electric chassis may be used as a conductor for the DC sections of a voltage class B1 electric circuit.
The electric chassis shall not be used as a conductor for the AC sections of a voltage class B1 electric
circuit.
An electric circuit may consist of sections with voltage class B1 and sections with voltage class A. In
this case the following conditions shall apply.
— At a single fault in this circuit the voltage of the voltage class A sections shall not exceed the limits
specified for voltage class A.
— The voltage class A sections shall be classified as voltage class A.
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ISO 6469-3:2018(E)

NOTE 1 A failure of an electronic switch is an example for a single fault.
NOTE 2 The measures in 6.3.5 can be applied to the components and/or cables of voltage class B1 electric
circuits.
6.1.3 General requirements for voltage class B2
Protection against electric shock for voltage class B2 shall be comprised of:
— provisions for basic protection; and
— provisions for fault protection.
The provisions for protection shall meet the requirements as described in 6.2. and 6.3.
Provisions for fault protection shall include 6.3.1, 6.3.2 and 6.3.3.
6.2 Basic protection
For basic protection, the requirement of basic insulation shall be fulfilled.
The protective provisions in 6.4 shall apply.
...