What is IEC 62955 DC 6mA current leakage protection?

IEC 62955 - Residual direct current detecting device (RDC-DD) to be used for mode 3 charging of electric vehicles.

This International Standard applies to residual direct current detecting devices (RDC-DD) for permanently connected AC electric vehicle charging stations (mode 3 charging of electric vehicles, according to IEC 61851-1 and IEC 60364-7-722), hereafter referred to as RDC-MD (residual direct current monitoring device) or RDC-PD (residual direct current protective device), for rated voltages not exceeding 440V AC with rated frequencies of 50Hz, 60Hz or 50/60 Hz and rated currents not exceeding 125A.

NOTE 1 - This document can also be used as guidance for devices for voltages up to and including 690V AC 50Hz, 60Hz or 50/60 Hz, at a rated current not exceeding 250A.

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.

NOTE 2 - The value of 6 mA for smooth residual direct current was chosen to prevent impairing the correct operation of an upstream type A or type F RCD.