Undervoltage release for S00–S3 breakers
The Siemens 3RV1902-1AF00-0FQ0 is an undervoltage release designed for circuit breakers in sizes S00 through S3. It operates on 110V AC at 50Hz and is listed as compatible with FA.ABB and Lovato branded breakers. The release mounts directly into the breaker's accessory slot, so no additional panel wiring is needed beyond the control circuit.
Integration into the breaker assembly
The release clips into the accessory slot on the left side of the 3RV2 breaker family. No DIN-rail space is consumed beyond the breaker itself. For a panel builder, the 110V AC control coil draws minimal current from the control transformer, leaving headroom for other auxiliaries. The dropout threshold is factory-set; no field adjustment is required. When wiring, ensure the control supply is fused separately from the motor power circuit to avoid nuisance trips from a shared fault.