The Siemens SIRIUS 3RH1131-2MB40-0KT0 is a coupling relay for switching auxiliary circuits, part of the SIRIUS family. This gives panel builders options when laying out a dense cabinet.
At 1.4 W per relay, a string of ten adds 14 W to the supply budget. Contact ratings span the common control voltages: 10 A at 24 V, 6 A at 230 V, 3 A at 400 V, 2 A at 500 V, and 1 A at 690 V. The AC-12 rating (10 A) covers resistive and solid-state loads typical in auxiliary circuits — not motor starting. This is a key spec for panels near VFDs or welding equipment. This is standard for panel-mounted control gear; keep it inside an enclosure rated for the environment. The shock resistance of 10g for 5 ms and 5g for 10 ms covers most industrial vibration profiles without needing additional damping.
Wiring and integration
The depth of 73 mm, width of 45 mm, and height of 60 mm mean it occupies about the same footprint as a typical ice-cube relay but with higher mechanical endurance (30 million operations typical). Side clearances are 0 mm, so relays can be mounted side-by-side without spacing — useful when packing multiple units on a DIN rail. Above that, you'd need to account for reduced dielectric strength in thinner air.
If you're cross-referencing against a panel originally built around a 3RT1015 series contactor, note that the 3RH1131 is a dedicated auxiliary contactor — it lacks main power contacts. It's designed to be driven by a PLC output or a larger contactor's auxiliary circuit, not to switch motor loads directly.