125 A Type B RCCB for 4-wire outgoing circuits
The Schneider Electric A9R44492 is an Acti9 RCCB-ID residual current circuit breaker rated 125 A in a 4-pole (4P) configuration with 300 mA earth-leakage sensitivity and Type B protection class. Type B means it detects AC, pulsating DC, and smooth DC fault currents up to 1 kHz — essential for variable-speed drives, UPS systems, and PV inverters that can inject DC components into the earth path. The 125 A rating and 400 V AC operational voltage suit it for main incoming or large submain protection in three-phase panels. Rated breaking and making capacity is 1250 A at 400 V (IEC/EN 61008-1), which covers the prospective fault current typical of a 125 A outgoing circuit in a commercial or light-industrial distribution board. The instantaneous trip characteristic means no intentional delay — it clears earth faults within the standard response time.
The 76 mm depth and 86 mm height are standard for the Acti9 modular range, so it fits existing distribution boards without re-spacing. Tunnel-type terminals accept up to 50 mm² rigid or 35 mm² flexible cable — enough for 125 A incoming tails. Tightening torque is 3 N.m; wire strip length 11 mm. IP20 finger protection on the terminals, IP40 for the modular enclosure. Padlockable toggle for lockout/tagout. The red/green trip indicator gives a clear visual on the residual current device status without opening the panel door.
The A9R44492 is listed at a current lifecycle stage with no announced end-of-life or last-time-buy. It remains an active catalog item in the Acti9 range.
Standards compliance and approvals
Designed and tested to IEC/EN 61008-1, IEC/EN 61008-2-1, and IEC/EN 62423. Carries VDE quality label. Pollution degree 3 (industrial environment). The 8/20 µs impulse withstand rating of 3 kA means it survives surge events common in mains-fed panels without nuisance tripping.