The Siemens SIRIUS 3RH1122-2BN40 is a size S00 auxiliary contactor rated for 10 A at AC-12 duty (resistive load) up to 250 V. That AC-12 rating means it's built for switching resistive loads like heaters or control transformers — not motor starts. The coil holds at 3.2 W DC, making it compatible with standard 24 VDC PLC outputs without a separate power supply.
Mounts via screw or snap-on onto DIN rail. The 45 mm width (three 17.5 mm modules) fits standard panel layouts. Mounting position allows ±180° rotation on vertical surfaces and ±22.5° tilt forward/backward — useful when panel depth is tight. IP20 on the front is standard for enclosed panels; no washdown rating here.
Ratings and switching capacity
Rated operational current varies by voltage: 10 A at 24 V, 6 A at 230 V, 3 A at 400 V, 2 A at 500 V, 1 A at 690 V. The DC switching curve drops faster: 1 A at 110 V, 0.27 A at 220 V. Surge voltage resistance is 6 kV, pollution degree 3 — suitable for industrial environments with conductive dust or condensation. Contact reliability is rated at one failure per 100 million operations at 17 V, 1 mA, which is typical for low-level signal switching.