BS7671 Amendment 2 – heat pump installations – Type B RCDs

By Chaz Andrews, Technical Manager, Doepke UK Ltd
Heat pumps (HP) producing leakage currents above 1kHz, will not be compatible with Type B RCDs that are only manufactured to meet the lowest requirement of BSEN62423, i.e. operation up to 1kHz.
Type B RCDs rated for use up to 1kHz may trip unexpectedly when subjected to leakage currents above 1kHz, or worse, the detection circuit may be saturated (blinded). This will result in the device not detecting residual currents under fault conditions.
BS7