BS IEC 62955:2018

What is BS IEC 62955‒ Residual direct current detecting device about?

BS IEC 62955 is an international standard that covers general specifications for Residual direct current detecting devices.

BS IEC 62955 applies to residual direct current detecting devices (RDC-DD) for permanently connected AC electric vehicle charging stations (mode 3 charging of electric vehicles), referred to as RDC-MD (residual direct current monitoring device) or RDC-PD (residual direct current protective device), for rated voltages not exceeding 440 V AC with rated frequencies of 50 Hz, 60 Hz or 50/60 Hz and rated currents not exceeding 125 A.

BS IEC 62955 covers two different classes of residual direct current detecting device (RDCDD) to be used for mode 3 charging of electric vehicles:

• RDC-MD (monitoring devices)
• RDC-PD (protective devices)

BS IEC 62955 applies to devices performing simultaneously the functions of detection of the residual direct current, of comparison of the value of this current with the residual operating value and initiating the opening of the circuit when the residual direct-current exceeds 6 mA. Note 1: RDC-PDs according to BS IEC 62955 are suitable for isolation.

Note 2: BS IEC 62955 can also be used as guidance for devices for voltages up to and including 690 V AC 50 Hz, 60 Hz or 50/60 Hz, at a rated current not exceeding 250 A.

Who is BS IEC 62955‒ Residual direct current detecting device for?

BS IEC 62955 on residual direct current detecting device is useful for:

• Manufacturers and suppliers of residual DC detecting device
• Dealers and distributors of residual DC detecting device
• Designers and developers of residual DC detecting device
• Test/ service providers for residual DC detecting device

Why should you use BS IEC 62955‒ Residual direct current detecting device?

RDC-DDs are intended to remove or initiate removal of the supply to the EV in cases where a smooth residual direct current equal to or above 6 mA is detected.

BS IEC 62955 specifies detecting equipment termed as residual direct current detecting device that helps you ensure the proper functionality of RCDs type A or type F is not impaired by DC residual currents above 6 mA. It gives appropriate measures for RCD type B, or RCD type A as well as appropriate equipment that helps you ensure the switching of the supply in case of a DC fault current above 6 mA.

BS IEC 62955 gives you protective measures against DC fault currents, by specifying the requirements for construction and operation and various test methods. Users can ensure safety by protecting each connecting point by its own RCD of type A, having a rated residual operating current not exceeding 30mA.