The Schneider Electric A9R82240 is a 2-pole residual current circuit breaker (RCCB) from the Acti9 iID family, rated at 40 A with 300 mA earth-leakage sensitivity. The unit is voltage-independent for its tripping mechanism, so it clears a ground fault even if the line voltage collapses.
The 40 A current rating suits main incomers or sub-main circuits feeding a distribution board. The 300 mA sensitivity is a delayed-action or high-threshold trip — it is not for personal shock protection (that requires 30 mA or lower); instead it is used for fire protection or as a backup to individual 30 mA RCDs, or on circuits where nuisance tripping from leakage is a concern.
Breaking capacity and durability
The A9R82240 has a rated breaking and making capacity of 1500 A (Idm and Im), which is the standard for domestic RCCBs. It is rated for 15000 electrical cycles under AC-1 (resistive load) and 20000 mechanical cycles — figures that reflect a service life well beyond typical residential or light commercial duty cycles. The instantaneous trip response means no intentional delay; the RCCB opens as soon as the residual current exceeds the 300 mA threshold.
Terminals accept up to 35 mm² rigid or 25 mm² flexible conductors; strip length is 14 mm and tightening torque is 3.5 N.m.
Designed and certified to GB 16916.21 and EN/IEC 61008-1, the governing standards for residual current operated circuit-breakers without integral overcurrent protection. The 8/20 µs impulse withstand of 250 A per EN/IEC 61008-1 confirms it handles surge currents from lightning or switching transients without nuisance tripping. Pollution degree 3 rating suits the controlled but non-clean environment inside a distribution cabinet.