The Schneider Electric A9Z63463 is a 4-pole residual current circuit breaker (RCCB) from the Acti9 iID series, rated 63 A with 300 mA earth-leakage sensitivity and Type B-SI (Super Immunised) protection. The Type B-SI classification means it detects smooth DC residual currents and is immunised against nuisance tripping from high-frequency harmonics — a fit for photovoltaic, variable-speed drive, and lift applications where standard AC or A types would false-trip.
Rated at 63 A continuous, this RCCB handles the full load current of a sub-distribution board feeding multiple drives or a PV inverter string. The 300 mA sensitivity is a deliberate choice for equipment protection rather than personnel shock — 30 mA is the touch-protection threshold; 300 mA is for fire and equipment damage prevention on circuits with high natural leakage (drives, UPS, PV). The Type B-SI (Super Immunised) label confirms it withstands 8/20 µs impulse currents up to 3 kA without tripping, so lightning-induced surges on a rooftop PV array won't drop the circuit.
Terminals accept double front or back entry: rigid up to 35 mm² front, flexible up to 25 mm² front. Tightening torque 3.5 N·m top or bottom. Wire strip length 14 mm. Screw shield provided. IP20 body, IP40 inside a modular enclosure. IK05 impact resistance. The toggle control gives local ON/OFF switching with a green LED for voltage presence and a trip indicator. Padlocking device compatible. Neutral on the left.