The Schneider Electric A9Z63440 is a 4-pole residual current circuit breaker (RCCB) from the Acti9 iID range, rated 40 A with 300 mA earth-leakage sensitivity. The Type B-SI (Super Immunised) classification means it handles smooth DC fault currents and high-frequency AC components — common on photovoltaic, variable-speed drive, and lift installations where standard AC or A types would nuisance-trip.
Rated at 40 A (In) and 300 mA sensitivity, this RCCB protects against earth faults in circuits supplying motor drives, UPS feeds, or PV inverters. The 300 mA threshold suits equipment-level protection where 30 mA would cause unwanted tripping from natural leakage. Insulation voltage is rated 500 V (Ui), overvoltage category IV, pollution degree 3 — suitable for main incoming panels in industrial environments. The 8/20 µs impulse withstand of 3 kA per EN/IEC 61008-1 covers surge events on the supply side. Electrical durability is 15,000 cycles, mechanical 20,000 cycles — typical for a panel-mounted RCCB on a distribution board, not a switching duty device.
Installation and integration details
Clip-on mounting on DIN rail, 72 mm wide (4 modules). Tightening torque 3.5 N.m. IP20 rated (fingertip-safe) with IP40 inside the modular enclosure. IK05 impact resistance. Green LED indicates voltage presence; a mechanical trip indicator shows the contact position. Neutral on the left, 50 Hz network, AC only.