The Schneider Electric A9W24263 is an Acti9 Vigi iC60 add-on residual current device (RCD) — a voltage-independent, Type A earth-leakage module that clips onto the outgoing side of an iC60 MCB to add 300 mA ground-fault protection. Rated 63 A continuous at 230/415 V AC, 50/60 Hz, it covers the standard residential and light-commercial outgoing circuits. The 2-pole form factor (2P) suits single-phase or two-wire protected circuits, and the instantaneous trip means no intentional delay — it clears the fault as fast as the internal sensing allows.
The 63 A rated current (In) and 300 mA earth-leakage sensitivity are the two numbers that decide whether this RCD fits your BOM line. At 63 A it matches the thermal capacity of a 63 A MCB upstream — pair it with a lower-rated breaker and the RCD is over-specced but still fine; pair it with a higher-rated breaker and the RCD becomes the weak link. The 300 mA sensitivity is a standard for general-purpose socket-outlet protection in many IEC territories (IEC 61009-1 governs the combined RCBO function here). Type A detection handles pulsating DC fault currents from electronics and rectifiers — the most common residual-current shape outside pure sinusoidal AC. Mounting is clip-on DIN rail (4 x 9 mm pitches wide, so 36 mm). The tunnel-type terminals accept 1–35 mm² rigid or 1–25 mm² flexible cable, stripped 14 mm, tightened to 3.5 N·m.