Siemens 3RV1921-1M Signalling Switch Sirius Screw Connection

Siemens 3RV1921-1M Signalling Switch is a Sirius signaling device designed to mount on 3RV1 series circuit breakers to provide a dedicated trip signal and a short‑circuit alarm. It features one normally open and one normally closed auxiliary contact, enabling separate signaling paths for control logic and fault indication. The unit uses screw‑type terminals for the auxiliary circuit, accepts conductors up to 2.5 mm², and is designed for plug‑in mounting with compact dimensions of 18 mm in width, 90 mm in height and 68 mm in depth. Electrical ratings include up to 10 A for AC‑12 operation across voltages from 24 V to 690 V, with AC‑15 operation of 6 A at 24 V, 4 A at 230 V, and 3 A at 400 V; DC‑13 ratings are 2 A at 24 V, 0.5 A at 110 V, and 0.25 A at 220 V. This 3RV1921-1M is a legacy signaling switch for the 3RV1 family, and Siemens lists a migration path to Sirius 3RV2 (for example 3RV2921‑1M).