The Schneider Electric A9R14240 is a 2-pole residual current circuit breaker (RCCB) from the Acti9 iID range, rated for 40 A continuous current with 300 mA earth-leakage sensitivity, Type AC, for 220-240 V AC 50/60 Hz networks. Let me show you why the ratings matter for a panel build: the 300 mA sensitivity means it's sized for general distribution protection — not for personal shock protection (that's the 30 mA class) — so it's a fit for submain or feeder circuits where you want ground-fault isolation without nuisance tripping on normal equipment leakage.
Rated breaking and making capacity is 1500 A (both Idm and Im) per EN/IEC 61008-1. That's the standard interrupting rating for this class of RCCB — it's designed for fault currents typical in final distribution, not high-fault service-entrance duty. The 250 A surge current (8/20 µs impulse) tells you it can handle lightning-induced transients on the line side without welding the contacts shut. Voltage-independent tripping is a detail worth flagging: the residual current detection circuit doesn't need a separate power supply — it steals energy from the fault itself, so the RCCB trips even if the neutral is lost upstream. That's good for fail-safe behavior, but it also means the trip characteristic doesn't change if the line voltage sags.
Installation details
The toggle handle has a contact position indicator (green/red band) and accepts a padlocking device for lockout/tagout. Electrical durability is 15000 cycles under AC-1 resistive load; mechanical durability is 20000 cycles.