AS ISO 6469.3:2014 pdf free download – Electrically propelled road vehicles – Safety specifications
8.2.3 Isolation resistance measurement of the voltage class B electric power sources
The measurement of the isolation resistance of an RESS, if any, shall be in accordance with ISO 6469-1 . The measurement of the isolation resistance of a fuel cell stack, if any, shall be in accordance with ISO 6469-1 with the fuel cell stack in operation. Alternatively for the measurement of the isolation resistance of a fuel cell stack, the entire mechanical structure of the fuel cell system (including the cooling system with its cooling medium) shall be considered. Prior to the measurement, stop power generation after operation at maximum output according to the manufacturer’s specification. The voltage across the fuel-cell stack power terminals shall be discharged. All cables shall be disconnected from the fuel-cell stack power terminals, and all other cables from other electric terminals of the fuel-cell stack. All cooling pipes, fuel pipes, and air pipes shall remain connected. The applied test voltage shall be at least the maximum open circuit voltage of the fuel cell stack. Apart from these specific conditions, the procedure shall be performed as given in 8.2.2.
8.2.4 Isolation resistance measurement of entire voltage class B electric circuits
The isolation resistance of entire conductively connected voltage class B electric circuits may be measured using the test procedure for the measurement of the RESS given in ISO 6469-1 with the balance of electric power system connected to the voltage class B power sources. Alternatively, the isolation resistance of entire conductively connected voltage class B electric circuits may be measured using an isolation resistance monitoring system, if installed on the vehicle, provided that its accuracy is sufficiently high. In case electric or electronic switches exist in the circuit (e. g. transistors in power electronics), these switches shall be activated. If these switches cannot be activated, the relevant part of the circuit may be measured separately in accordance with 8.2.2. Instead of being measured, the isolation resistance of the entire conductively connected circuit may be calculated using the measured resistances of the power sources and the balance of electric power system.
8.3.3.2 Test voltage for components not conductively connected to the grid
The test voltage, a.c. or d.c., shall be more than the highest voltage that can actually occur to the component. The test voltage shall be derived from the relevant over-voltages of the electric circuit to which the component is connected. Transient over-voltages that can be expected, including influences from other connections to grid, if any, shall be considered. The test voltage and its duration shall be specified, considering the applicable parts and sections of IEC 60664 by the vehicle manufacturer. These test requirements also apply for voltage class B components connected to d.c. charging systems that are not conductively connected to the a.c. grid.