The Siemens 3RH1431-1BB40 is a SIRIUS auxiliary contactor in size S00 — a compact, 3-pole normally-open switching block meant for control circuits, not motor loads. Its 24 V DC coil pulls in at 0.8 x rated voltage (about 19.2 V) and holds at 3.2 W DC, so the power supply needs to deliver that continuously, not just the inrush. The three NO contacts are rated for 10 A at 24 V, and derate predictably at higher voltages: 6 A at 230 V, 3 A at 400 V, 1 A at 690 V. That's the contact rating for AC loads; for DC switching, check the same table — 1 A at 110 V, 0.27 A at 220 V.
That helps when you're packing a dense panel and need to orient the contactor to reach the wiring ducts.
Wiring and contact configuration
Terminals accept solid or stranded wire: 2x 0.5...1.5 mm², 2x 0.75...2.5 mm², or 2x 4 mm² per clamp. For AWG, that's 2x 20...16, 2x 18...14, or 1x 12. The three instantaneous contacts are all NO — no NC or changeover built in. If you need a delayed or make-before-break contact, this variant doesn't offer it (those flags are zero). But the product extension auxiliary switch is listed as 'Yes', meaning you can add a separate auxiliary switch block on top if the circuit demands an NC or extra NO.
Environmental and electrical endurance
Rated for pollution degree 3. Shock resistance is 10g / 5 ms and 5g / 10 ms. Mechanical life is 5 million operating cycles typical.