The Siemens SIRIUS 3RH2131-1WB40 is a coupling relay for switching auxiliary circuits, built in the compact S00 contactor footprint.
The 10 A rating at 24 V is the thermal current — it governs the resistive load capacity on each contact. For inductive loads like small contactor coils or solenoid valves, derate per the AC/DC switching curves; the part lists separate ratings at 60 V (4.7 A), 110 V (3 A), 230 V (10 A), and 400 V (3 A) to cover common control voltages. The 3 NO contacts let you switch three independent circuits from one coil, useful for interlocking or signal duplication in a panel. Electrical switching frequency is 10,000 1/h at AC, with arcing time 10–15 ms.
The relay measures 45 mm wide, 57.5 mm tall, and 73 mm deep — the S00 footprint.