The Siemens 3RH1131-1AF00-0TK1 is a SIRIUS auxiliary contactor in size S00 — a compact 45 mm wide block that adds four normally-open instantaneous contacts to a contactor or motor starter assembly. The IP20 front protection means the terminals are finger-safe once wired; no additional cover needed inside an enclosed panel.
Switching capacity drops with voltage: 6 A at 230 V, 3 A at 400 V, and 1 A at 690 V. For DC loads, the same contacts handle 1 A at 110 V and 0.27 A at 220 V. The mechanical life is listed at 30 million switching operations; contact reliability is rated for one incorrect operation per 100 million cycles at 17 V, 1 mA, which matters for PLC-level signal switching where dry-circuit performance is critical.
The contactor accepts solid conductors: two per clamp for 0.5–1.5 mm², two for 0.75–2.5 mm², and two for 4 mm². The screw terminals are captive. Dimensions are 45 mm wide, 57.5 mm high, 72 mm deep — standard S00 envelope, so it fits existing panel layouts without re-drilling. Shock resistance is 10g / 5 ms and 5g / 10 ms; ambient operating range is -25 to +60 °C.