Auxiliary contactor for control-circuit switching
The Siemens SIRIUS 3RH1122-1KG40-0LA2 is an auxiliary contactor in size S00, designed for switching control circuits in motor starter and relay logic applications. It carries a 10 A rated value at 24 V, with the contact reliability spec of one incorrect switching operation per 100 million cycles at 17 V, 1 mA — meaning it's built for high-integrity signal paths, not just power switching. The coil draws 11 W on closing and holds at 4 W, so the thermal load on the control transformer is modest.
DIN-rail footprint and panel fit
At 45 mm wide, 57.5 mm tall, and 72 mm deep, this contactor fits the standard S00 footprint and mounts via screw or snap-on onto a DIN rail. The IP20 front protection means it's suitable for enclosed panels where personnel don't contact live parts. Mounting position is flexible: ±180° rotation on a vertical surface, plus ±22.5° forward/backward tilt — useful when fitting into a crowded gland plate area.
Switching ratings across voltages
The rated switching current drops with voltage: 10 A at 24 V, 6 A at 230 V, 3 A at 400 V, 2 A at 500 V, and 1 A at 690 V. The 125 V rated value appears as a separate spec line — likely the rated insulation voltage or a reference point for the contact block. The 6 kV surge voltage resistance (impulse withstand) aligns with pollution degree 3 environments, typical for industrial control panels without climate control.
Mechanical endurance and environmental range
Rated for 30 million mechanical switching operations, with shock resistance of 10g at 5 ms and 5g at 10 ms. Operating temperature spans -40 to +70 °C, storage and transport from -55 to +80 °C. The solid conductor terminals accept 2x (0.5 to 1.5 mm²), 2x (0.75 to 2.5 mm²), or 2x 4 mm² — covering most control-wiring gauges used in panel building.