The Schneider Electric A9Z31291 is an Acti9 iID residual current circuit breaker (RCCB) — 2 poles, rated 100 A continuous, with 30 mA earth-leakage sensitivity. It clips onto a DIN rail (36 mm wide, 73 mm deep, 91 mm tall) and occupies 4 x 9 mm pitches in the panel. The Type A-SI (Super Immunised) designation means it handles pulsed DC fault currents (typical from electronics/rectifiers) and resists nuisance tripping from high-frequency leakage, so it's suited for mixed-load final circuits where VFDs or switched-mode supplies share the sub-board.
Mounts via clip-on onto a DIN rail (snap-on). Strip length 14 mm. Tightening torque 3.5 N·m top or bottom. The IP20 body is fine for enclosed distribution boards; IP40 with modular enclosure.
Insulation voltage 500 V AC. Impulse withstand 6 kV. Breaking capacity Idm 1500 A, conditional short-circuit current 10 kA. Electrical durability 10,000 cycles (AC-1), mechanical 20,000 cycles. Instantaneous tripping, voltage-independent residual current technology. Standards EN/IEC 61008-1 and 61008-2-1. 8/20 µs impulse withstand 3000 A per EN/IEC 61008-1.