The Siemens SIRIUS 3RH2140-1WB40 is a coupling relay for switching auxiliary circuits, built into the S00 contactor footprint. It carries 4 normally-open instantaneous contacts and a 24 VDC coil with integrated varistor surge suppression.
The S00 size (45 mm wide) matches the footprint of Siemens 3RT2 contactors in the same frame — it clips directly to the left or right of the contactor using the integrated snap-on feature.
The 4 NO contacts are rated for AC switching at multiple voltages: 10 A at 24 V, 4.7 A at 60 V, 3 A at 110 V, 1.2 A at 220 V, 10 A at 230 V, 3 A at 400 V, 0.5 A at 440 V, 2 A at 500 V, 0.26 A at 600 V, and 1 A at 690 V. Arcing time runs 10 to 15 ms. The varistor surge suppressor across the coil absorbs back-EMF, which matters when the relay is driven by a PLC output — no external flyback diode needed.
Wire termination accepts solid or stranded conductors: 2× (0.5 to 1.5 mm²), 2× (0.75 to 2.5 mm²), or 2× 4 mm². The product extension auxiliary switch is not included (no add-on block). Relative humidity minimum 10%.