The Schneider Electric A9Q04240 is an add-on residual current device (RCD) from the Acti9 Vigi iC60 range, designed to plug directly onto the busbar side of a compatible iC60 miniature circuit breaker (MCB) to add earth-leakage protection in a single-width module. Rated 40 A and 300 mA sensitivity, AC type, instantaneous — so it trips on sinusoidal AC fault currents with no intentional delay. The 300 mA threshold suits sub-main or feeder circuits where a 30 mA RCD would nuisance-trip on cumulative leakage (multiple loads, long cable runs). Voltage-independent tripping means the solenoid operates from the fault current itself, not from a powered electronic circuit — it still clears a ground fault even if the phase voltage is lost.
Clip-on to a 35 mm DIN rail, 2-pole width (36 mm, 4 x 9 mm pitches). Plugs directly onto the bottom of an iC60 MCB — no additional wiring between breaker and RCD. Designed as an outgoer device in the final distribution board. IP20 on the front face; IP40 inside the modular enclosure when all blanking plates are fitted. Bottom tunnel terminals accept 1 to 35 mm² rigid cable (or 1 to 25 mm² flexible with/without ferrule). Comb-busbar compatible on the bottom side.
Designed and certified to EN/IEC 61009-1 and EN/IEC 61009-2-1 (RCDs for household and similar uses). Rated insulation voltage 500 V AC; rated impulse withstand voltage 6 kV per IEC 60947-2. 8/20 µs impulse withstand tested at 250 A per IEC 61009-1 — meaning it survives surge events common in industrial mains without nuisance tripping or damage.