The Schneider Electric A9V71463 is an Acti9 Vigi iC60 add-on residual current device (RCD) — a 4-pole, 63 A unit with 30 mA earth-leakage sensitivity, Type A-SI (Super Immunised), instantaneous trip. It clips onto the DIN rail alongside the matching iC60 MCB to provide combined overcurrent and earth-leakage protection in a two-module stack. The voltage-independent trip mechanism means it clears a ground fault even if the line voltage collapses — a real advantage on circuits where a lost neutral could otherwise silence a conventional RCD.
The 30 mA sensitivity catches leakage that would be hazardous to personnel; Type A-SI (Super Immunised) handles pulsed DC fault currents from electronics and resists nuisance tripping from high-frequency noise, so it's a good fit on circuits feeding VFDs, UPS units, or switching power supplies. Instantaneous trip means no intentional time delay — it clears within the standard RCD response window, which is what you want for shock protection but means you cannot coordinate it downstream of another instantaneous RCD. The 8/20 µs impulse withstand of 3000 A per IEC 61009-1 confirms it survives surge events without internal damage.
Clip-on mounting to DIN rail, 7 x 9 mm pitches wide (63 mm). The screw connection to the adjacent MCB means you wire the phase and neutral through the MCB first, then the RCD picks up the outgoing side. Trip indicator on the front gives a local visual of whether it's the RCD that opened, which saves chasing the wrong device in a multi-way board.