The Schneider Electric A9Q61340 is a 3-pole add-on residual current device (RCD) from the Acti9 Vigi iC60 series, rated 40 A with 30 mA earth-leakage sensitivity. It clips onto the side of an Acti9 iC60 miniature circuit breaker (MCB) via the plug-in electrical connection, making it a combined RCBO assembly in a single DIN-rail footprint. The 63 mm width and 73.5 mm depth fit standard 9 mm pitch enclosures — it occupies 7 pitches. This is an outgoer device, meaning it sits downstream of the main breaker to protect a specific final circuit.
Why the Type A-SI and 30 mA matter
The Type A-SI (Super Immunised) earth-leakage protection is voltage-independent — it trips on residual current alone, without needing a separate power supply. The "SI" suffix means it's hardened against nuisance tripping from high-frequency leakage and transient surges common on drives, inverters, and switching power supplies. In a mill environment with VFDs and contactor coils, standard Type A RCDs can false-trip on the capacitive leakage from drive input filters; the A-SI holds through that. The 30 mA sensitivity catches direct-contact faults (hand-to-ground currents above the let-go threshold) while the instantaneous time delay clears the fault in under 40 ms — no intentional delay for selectivity. The 8/20 µs impulse withstand of 3000 A means it survives lightning-induced or switching surges without damage.
Mounting is clip-on to a DIN rail, with the plug-in connection to the adjacent iC60 MCB. The tunnel-type terminals on the bottom accept 1 to 35 mm² rigid cable (or 1 to 25 mm² flexible, with or without ferrule). The bottom busbar and distribution block compatibility means you can feed the line side via a comb busbar across multiple devices. The IP20 rating covers the device body; in a modular enclosure it reaches IP40 — sufficient for enclosed distribution boards but not for washdown locations.