The Siemens SIRIUS 3RV1922-1CS0 is an undervoltage release designed for motor-protective circuit breakers in the S0 through S3 frame sizes. It operates at 500 V AC, 50 Hz and includes a leading auxiliary switch with 2 normally-open contacts.
Integration note
The release mounts directly onto the side of a 3RV1 circuit breaker in sizes S0, S1, S2, or S3. No additional DIN-rail space is consumed; it clips onto the breaker housing. The 2 NO auxiliary switch signals the undervoltage state back to the control system.