What it is and what it does
The Siemens 3RH1122-1AN10 is a SIRIUS auxiliary contactor in frame size S00. It provides 2 normally open (instantaneous) contacts for switching control circuits, signal feedback, or interlocking in motor starter assemblies and general control panels. The AC-12 rated operational current is 10 A, which covers most 24 VDC and 230 VAC pilot-duty loads you’ll encounter on a typical line. Rated switching capacity varies by voltage: 10 A at 24 V, 6 A at 230 V, 3 A at 400 V, and 1 A at 690 V. That means it handles the full range of common control voltages without derating the contact block — one part covers 24 VDC relay coils, 230 VAC solenoid valves, and 400 VAC contactor coils. Contact reliability is specified as one incorrect switching operation per 100 million operations at 17 V, 1 mA — a dry-circuit rating that matters for PLC inputs or low-energy signal paths where oxide films on silver contacts can cause intermittent opens.
Mounting and integration
Fastening is screw and snap-on mounting — it clips directly onto a 35 mm DIN rail (EN 60715) and can also be panel-screwed if needed. The mounting position is flexible: ±180° rotation on a vertical surface, and tilt forward/backward by ±22.5°, which helps when routing wires in a crowded enclosure. Dimensions are 72 mm deep, 45 mm wide, 57.5 mm high — size S00 footprint. That 45 mm width is a single modular unit on the DIN rail, so it occupies one slot in a typical panel layout. Wire capacity: accepts 2x (0.5…1.5 mm²), 2x (0.75…2.5 mm²), or 2x 4 mm² solid/stranded, plus AWG equivalents (2x 20…16, 2x 18…14, 1x 12). IP20 protection on the front means it’s safe for finger contact in a closed panel — no extra shrouding needed inside the enclosure, but not rated for washdown or outdoor exposure.
Environmental and electrical endurance
Operating temperature is -25 to +60 °C; storage and transport range is -55 to +80 °C. Shock resistance: 10g / 5 ms and 5g / 10 ms. Pollution degree 3 (conductive pollution or dry non-conductive pollution that becomes conductive due to condensation — typical for industrial control panels not in clean rooms). Mechanical endurance is 30 million operating cycles typical — that’s the life of the contactor body, not the contacts. Surge voltage resistance is 6 kV, which aligns with IEC 60947-1 overvoltage category III for fixed installations.