The Siemens SIRIUS 3RV1902-1AB0 is an undervoltage release (trip coil) designed for motor circuit breakers in the S00, S0, S2, and S3 frame sizes.
Integration and fit
The 18.5 mm width and 68 mm depth mean it occupies one 18 mm module slot on the rail, leaving the adjacent space free for auxiliary contact blocks or other add-ons. The 90 mm height is consistent with the S00–S3 breaker family, so it aligns vertically with the breaker body in a multi-row enclosure.
The 24 V AC control voltage at 50 Hz is the coil rating — not a main circuit voltage. This release is wired to a separate control transformer or 24 V supply, not to the motor power circuit. The 690 V insulation rating confirms the coil can be safely installed in a panel with 400 V or 480 V main circuits without additional creepage distance beyond what the degree of pollution 3 rating already accounts for. Because it's designed for motor circuit breakers (not contactors or load switches), the release interfaces with the breaker's internal trip mechanism. It does not carry any auxiliary contacts — the count for NO, NC, and CO contacts is zero on all three types — so any remote status indication must come from a separate auxiliary switch block mounted on the breaker.