The Schneider Electric A9Z14491 is an Acti9 iID residual current circuit breaker (RCCB) — a 4-pole, 100 A device with 300 mA earth-leakage sensitivity, Type AC, voltage-independent tripping.
Breaking and making capacity is listed as Idm 1500 A / Im 1500 A. If the fault current exceeds 1.5 kA, an upstream limiting device (MCB or fuse) is needed to keep the let-through within the RCCB's rating. The 300 mA sensitivity is instantaneous (no time delay), so it trips as soon as the residual current exceeds that threshold. Type AC means it detects sinusoidal AC earth faults only — not pulsed DC or smooth DC — which is fine for circuits feeding resistive, inductive, or conventional electronic loads without rectifiers or inverters. For variable-speed drives, UPS systems, or LED drivers that generate DC fault currents, a Type A or Type B RCCB would be required. Voltage-independent tripping means the RCCB does not rely on the line voltage to operate — it uses the fault current's own energy to trip. That is a reliability advantage: if the neutral is lost or the voltage drops, the device still provides earth-leakage protection.
Terminals accept double conductors up to 35 mm² rigid (front) or 25 mm² flexible.