The Schneider Electric A9Q31340 is an add-on residual current device (RCD) from the Acti9 Vigi iC60 range — a voltage-independent, instantaneous-trip module that plugs into the side of an iC60 MCB to add earth-leakage protection. It is rated 40 A, 30 mA sensitivity, Type A-SI (Super Immunised), meaning it handles pulsed DC fault currents and resists nuisance tripping from high-frequency harmonics common on VFD-fed or UPS-backed circuits. Three-pole (3P) construction clips onto DIN rail, occupying 7 modules of 9 mm pitch (63 mm wide).
Lifecycle reality — obsolete, but available
The A9Q31340 is marked obsolete by Schneider Electric. If you are holding a last-time-buy window or managing a legacy panel, this is the part to source now; there is no direct drop-in replacement from the manufacturer.
Rated operational voltage is 400…415 V AC, 50/60 Hz, per EN/IEC 61009-1 and -2-1 — the standard for residual-current-operated circuit-breakers with integral overcurrent protection. Type A-SI (Super Immunised) means it withstands 8/20 µs impulse currents up to 3000 A without tripping, so it holds steady on circuits with surge suppressors or switching transients. Instantaneous trip time means no intentional delay — it clears a ground fault as fast as the coil can move.
Clip-on mounting to DIN rail, 63 mm wide (7 x 9 mm pitches). Depth is 73.5 mm, height 91 mm. IP20 on the body, IP40 inside a modular enclosure. Bottom comb busbar compatible. The trip indicator gives local visual confirmation of a residual-current event — useful for panel troubleshooting.