Eaton xEffect FRCdM Residual Current Circuit Breaker (RCCB) — Type Bfq, 4-Pole, 40 A, 300 mA, Short-Time Delayed (167905)

The Eaton 167905 is a residual current circuit breaker (RCCB) from the Moeller series xEffect FRCdM range. It disconnects the circuit when the current flowing out does not match the current returning — the signature of a fault to earth, whether through failed insulation or through a person. It provides no overcurrent protection of its own and is installed together with the circuit's MCB or fuse. This device is 4-pole, rated 40 A, with a rated residual current of 300 mA. Type Bfq is Eaton's type B variant with a tripping curve adapted to reliably sense residual currents up to 50 kHz. It is the frequency-converter type, for installations whose normal operating leakage is itself high-frequency and would otherwise cause nuisance tripping or, worse, mask a real fault. Bfq and B+ are not interchangeable: B+ is chosen for fire protection, Bfq for drive-heavy installations. It is the G (short-time delayed) version, which rides through the brief leakage surges that switching and cable capacitance produce at energisation instead of tripping on them. At 300 mA it is intended for protection against earth-fault fire and for equipment protection, not for protection against direct contact — that requires a 30 mA device. Supplied by cBallast on quote-to-invoice terms; lead time and freight are quoted per RFQ against the destination Incoterm.