The Schneider Electric A9Y85725 is an Acti9 Vigi iC40 add-on residual current device (RCD) rated for 25 A continuous current and 300 mA earth-leakage sensitivity. It clips onto the outgoing side of a compatible Acti9 MCB via screws, making it a voltage-independent, instantaneous-trip RCD block for 3P+N circuits at 400 V AC, 50/60 Hz. The Type A-SI (Super Immunised) classification means it handles pulsed DC fault currents and resists nuisance tripping from high-frequency leakage typical of VFDs or UPS systems — a solid fit for mixed-load panels where standard Type A might false-trip.
Rated 25 A [In] and 300 mA sensitivity: this RCD protects a 25 A outgoing circuit against earth faults up to 300 mA — typical for general-purpose socket outlets or small distribution sub-circuits in commercial or light industrial panels. The 400 V AC operational voltage (Ue) matches standard three-phase four-wire networks. Voltage-independent tripping means the RCD breaks the circuit on residual current alone, even if the mains voltage collapses — a safety advantage over electronically-triggered units in fault conditions. Instantaneous time delay gives no intentional delay, so it trips within the standard IEC 61009-2-1 curve — use it where selectivity with upstream delayed RCDs is not required. Pollution degree 3 per EN/IEC 61009-2-1 and IP20/IP40 enclosure suit it for clean, dry indoor panel environments.
Clip-on DIN rail mount. 4 x 9 mm pitches wide. Neutral position left. Tightening torque 2 N·m. Wire strip length 14 mm. Local fault indication — a mechanical flag or window shows tripped status without needing to power the circuit.