The A9R71440S is a 4-pole residual current circuit breaker (RCCB) from the Acti9 iID series, rated 40 A at 380...415 V AC 50/60 Hz. The 30 mA earth-leakage sensitivity means it trips on ground faults at that threshold — standard for personnel protection in residential and commercial final circuits. Type AC detection covers sinusoidal AC residual currents only; if your load includes pulsed DC (VFDs, LED drivers, EV chargers), you need a Type A or Type B device instead. Voltage-independent tripping means it clears a fault even if the supply neutral is lost — a reliability edge over electronically tripped RCCBs. Rated breaking and making capacity is 1500 A (Idm and Im) per EN/IEC 61008-1 — adequate for the fault current available at the outgoer position in most distribution boards. The 6 kV impulse withstand voltage and pollution degree 3 confirm it's rated for the typical industrial panel environment, not just clean residential backboxes.
Clip-on mounting to DIN rail, 72 mm wide (4-module footprint at 9 mm pitch per pole). Neutral is on the left. Terminals accept 1...35 mm² rigid or 1...25 mm² flexible (with or without ferrule); strip length 14 mm, torque to 3.5 N.m. Padlocking provision and a contact-position indicator are present — useful for lockout/tagout and visual confirmation during fault isolation.