Undervoltage release for 3RV motor-protective breakers
The Siemens 3RV1902-1AV00-0FJ0 is an undervoltage release designed for the SIRIUS 3RV series of circuit breakers, covering frame sizes S00 through S3. It operates on a 400V AC, 50Hz control supply. When the control voltage drops below the dropout threshold, the release trips the breaker — a standard requirement for safety circuits that must de-energize motor loads on loss of control power.
What the rating means for fit
The 400V AC 50Hz rating defines the nominal coil voltage and frequency. This release mounts directly onto the side of the 3RV breaker — no separate wiring compartment needed. The dropout characteristic ensures the breaker opens when the control supply falls below roughly 70% of rated voltage, which is the standard undervoltage protection threshold for motor circuits per IEC 60947-2.