Auxiliary contactor for control-circuit switching
The Siemens 3RH2431-1BM40 is a SIRIUS auxiliary contactor with three normally open (3 NO) instantaneous contacts, sized S00 for compact panel builds. It mounts via screw or snap-on onto 35 mm DIN rail, with a depth of 73 mm, width 90 mm, and height 57.5 mm — fitting standard enclosure layouts without overhang. Switching capacity is specified per voltage: 10 A at 24 V and 230 V, 4.7 A at 60 V, 3 A at 110 V and 400 V, 1.2 A at 220 V, 0.5 A at 440 V, 2 A at 500 V, 0.26 A at 600 V, and 1 A at 690 V. These ratings cover the control-circuit loads you'd typically assign to an auxiliary contactor — PLC inputs, relay coils, signal lamps, and small solenoid valves — not motor power. Mechanical life is rated at 5,000,000 operating cycles typical, with a maximum switching frequency of 10,000 1/h at AC and an arcing time of 10–15 ms.
The 3RH2431-1BM40 accepts solid or stranded wire: 2x (0.5–1.5 mm²), 2x (0.75–2.5 mm²), or 2x 4 mm². Relative humidity minimum 10%. The part carries a product extension for an auxiliary switch (yes), so you can add a side-mounted block if the 3 NO contacts aren't enough for your signal feedback or interlock logic.