The Siemens 3RV1901-2E is a SIRIUS transverse auxiliary switch designed to mount on the front of SIRIUS 3RV circuit breakers in sizes S00, S0, S2, and S3. It provides one normally-open and one normally-closed instantaneous contact, wired through spring-loaded terminals that accept 2x (0.5... 2.5 mm²) solid or stranded wire, or 2x (20... 14) AWG.
Switching Capacity and Terminal Ratings
The auxiliary contacts are rated for 1 A at 24 V, 0.3 A at 48 V, 0.15 A at 60 V, and 0.5 A at 230 V. The AC-12 maximum operational current is 2.5 A. These ratings define the signal-level switching capability — enough for PLC inputs, contactor coils, and indicator lamps, but not for power circuits. Spring-loaded terminals accept solid or stranded conductors from 0.5 mm² to 2.5 mm² (2x per clamp), and finely stranded wire with or without end processing from 0.5 mm² to 1.5 mm². AWG range is 20 to 14 for auxiliary circuits. No screwdriver needed; strip to the correct length and push in.
Mounting and Environmental Range
The switch uses plug-in fixing onto the front of compatible SIRIUS 3RV breakers — no DIN rail required for the switch itself. Operating temperature range is -20 to +60 °C; storage range is -50 to +80 °C.
The 3RV1901-2E is a phased-out product. The official Siemens successor is the SIRIUS 3RV2901-2E, which uses the same contact configuration and spring-terminal design. For new builds or BOM updates, the 3RV2901-2E is the preferred direct replacement.