SIRIUS S00 auxiliary contactor — what it is and what it does
The Siemens 3RH1122-2AR60 is a SIRIUS S00 auxiliary contactor — a 4-pole switching block designed to extend the control-circuit contacts on a main contactor or to build a standalone interlock chain. Its primary job is to switch signal-level loads (PLC inputs, relay coils, pilot lights) rather than motor power, so the contact ratings are specified per voltage: 10 A at 24 V, 6 A at 230 V, 3 A at 400 V, and 1 A at 690 V. That spread tells you the contacts are silver-alloy, sized for control-circuit duty, not motor-circuit inrush.
Mounting and integration — fits the standard DIN-rail footprint
Fastening is screw and snap-on mounting, so it clips directly onto a 35 mm DIN rail or can be screwed to a mounting plate. The S00 body is 45 mm wide and 60 mm tall, with a depth of 73 mm — a compact footprint that leaves room for adjacent devices in a crowded panel. Mounting position is flexible: ±180° rotation on a vertical surface, plus ±22.5° tilt forward/backward, which helps when routing wires in tight enclosures.
Contact reliability and environmental ratings
Contact reliability is specified as one incorrect switching operation per 100 million operations at 17 V, 1 mA — that matters for PLC-level signals where dry-circuit switching can cause oxide buildup on standard contacts. The front face carries IP20 protection, meaning finger-safe but not sealed against dust or moisture; keep it inside a closed panel. Shock resistance is 10g / 5 ms and 5g / 10 ms, adequate for most industrial machinery but not for high-vibration applications like crushers. Operating temperature range is -25 to +60 °C, storage -55 to +80 °C.