BS ISO 6469-3:2011 pdf download – Electrically propelled road vehicles — Safety specifications Part 3: Protection of persons against electric shock
4 Environmental and operational conditions The requirements given in this part of ISO 6469 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 for guidance.
5 Voltage classes
Depending on its maximum working voltage, U, an electric component or circuit belongs to one of the voltage classes specified in Table 1.
6.1 Marking of voltage class B electric components
The symbol W 012 in accordance with ISO 7010 shown in Figure 1 shall appear on (preferably) or near voltage class B electric power sources as RESS and fuel cell stacks. The same symbol shall be visible on barriers and enclosures, which, when removed, expose live parts of voltage class B electric circuits. Accessibility and removability of barriers/enclosures should be considered when evaluating the requirement for the symbol.
6.2 Marking of voltage class B wiring
The outer covering of cables and harness for voltage class B electric circuits not within enclosures or behind barriers shall be marked with orange color.
Voltage class B connectors may be identified by the harnesses to which the connector is attached.
NOTE Specifications of the orange color 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 color system.
7 Measures and requirements for protection of persons against electric shock
Protection against electric shock shall be composed of
basic protection measures against direct contact with live parts;
measures for protection under single-failure conditions.
The protection measures shall meet the requirements as described in 7.2 and 7.3 and compliance shall be tested in accordance with the test methods specified in Clause 8.
7.2 Basic protection measures
Persons shall be protected against direct contact with the live parts of the voltage class B electric circuits.
The protection measures against direct contact shall be provided by either one or both of the following:
basic insulation of the live parts;
barriers/enclosures, preventing access to the live parts.
The barriers/enclosures may be electrically conductive or non-conductive.
7.3 Protection under single-failure conditions
7.3.1 Potential equalization As a general rule, exposed conductive parts of voltage class B electric equipment, including exposed conductive barriers/enclosures, shall be bonded to the electric chassis for potential equalization in accordance with the requirements in 7.9.
7.3.2 Isolation resistance The voltage class B electric circuits intended to be not conductively connected to the grid shall have sufficient isolation resistance in accordance with the requirements in 7.7.
If the minimum isolation resistance requirement of such circuits cannot be maintained under all operational conditions and over the entire service life, one of the following measures shall be applied: monitoring of the isolation resistance periodically or continuously; an appropriate warning shall be provided if loss of isolation resistance is detected; the voltage class B system may be deactivated depending on the operational state of the vehicle or the ability to activate the voltage class B system may be limited;
double or reinforced insulation instead of basic insulation;
one or more layers of insulation, barriers and/or enclosures in addition to the basic protection;
rigid barriers/enclosures with sufficient mechanical robustness and durability, over the vehicle service life.
Requirements on isolation resistance for voltage class B electric circuits intended to be conductively connected to the grid are given in 7.10.2.
NOTE 1 Isolation resistances below the required minimum values can occur due to deterioration of fuel cell (FC) systems’ cooling liquids or of certain battery types.
NOTE 2 Coordination between multiple isolation monitoring systems can be necessary, e.g. during charging.
NOTE 3 The isolation resistance is approximately zero for a voltage class B electric circuit conductively connected to the grid.
NOTE 4 Additional layer(s) of insulation and double or reinforced insulation include, but are not limited to, those for voltage class B wiring.