The Schneider Electric A9Z32240 is an Acti9 iID residual current circuit breaker (RCCB) — 2-pole, 40 A rated current, 100 mA earth-leakage sensitivity, Type A-SI (Super Immunised). It clips onto a DIN rail, occupies 4 x 9 mm pitches (36 mm wide), and is rated for 220-240 V AC 50/60 Hz networks. The 10 kA conditional short-circuit current (EN/IEC 61008-1) tells you it coordinates with a 10 kA upstream MCB without needing a separate backup fuse in most panel layouts.
The 100 mA sensitivity is the key selector here — it's not a 30 mA personal-protection device. The 40 A rating and 10 kA SCCR at 220-240 V AC mean it's sized for sub-main or feeder protection downstream of a 40 A or smaller MCB. The instantaneous trip (no intentional delay) and voltage-independent tripping mechanism mean it clears a fault even if the neutral is lost — a reliability point for safety circuits. The 3.5 N.m torque spec and 14 mm strip length are standard for this class. IP20 body, IP40 in a modular enclosure; fine for dry indoor panels, not for washdown areas.
Pollution degree 3 (industrial environment, not just clean office panels). The 6 kV impulse withstand voltage and 8/20 µs surge current withstand (3000 A) are built into the same standard compliance.