The Schneider Electric A9R11240 is an Acti9 iID residual current circuit breaker (RCCB) — a 2-pole, 40 A, 30 mA sensitivity device for AC networks. It is a Type AC, voltage-independent RCCB with instantaneous tripping, meaning it detects sinusoidal AC earth-leakage currents without needing a separate power supply for the detection circuit. This makes it a straightforward choice for general-purpose protection in residential and commercial distribution boards where the load produces no pulsed or DC fault currents.
Rated 40 A at 220...240 V AC, 50/60 Hz, this RCCB handles the full current of a typical lighting or general-purpose subcircuit. The 30 mA sensitivity is the standard for personal protection against electric shock — it will trip on leakage currents above that threshold, which is the level where ventricular fibrillation becomes a risk. The Type AC classification means it is designed for sinusoidal AC residual currents only; if the downstream loads include variable-speed drives, UPS systems, or other electronics that generate pulsed or DC fault currents, a Type A or Type F RCCB would be needed instead. The breaking capacity is rated at Idm 1500 A and Im 1500 A, which covers fault-clearing for most final circuits in a TN or TT system. The voltage-independent tripping technology means the device does not rely on the mains voltage to operate — it will still trip on a residual fault even if the neutral is lost upstream, a useful safety feature. It carries an 8/20 µs impulse withstand of 250 A per EN/IEC 61008-1, so it will not nuisance-trip from common surge events like nearby lightning strikes or capacitor switching.
Terminals accept 1...35 mm² rigid or 1...25 mm² flexible cable, with a wire stripping length of 14 mm and a tightening torque of 3.5 N.m.