Auxiliary contactor for control-circuit switching
The Siemens 3RH1122-1AU00 is a SIRIUS auxiliary contactor in the S00 frame size, designed for switching control circuits in motor starter and relay logic panels. It carries a rated operating current of 10 A at 24 V under AC-12 duty (resistive loads), with a maximum switching voltage of 240 V at 50/60 Hz. The contact arrangement provides 2 normally-open and 2 normally-closed instantaneous contacts — no delayed or make-before-break switching — so it's a straight signal repeater for PLC outputs or pushbutton circuits. Mounting is via screw or snap-on onto a DIN rail, and the 45 mm width fits the standard S00 footprint used across the SIRIUS contactor family. The IP20 front protection means it's suitable for enclosed panels where no washdown or dust ingress is expected. Operating temperature range of -25 to +60 °C covers most industrial environments short of direct oven proximity.
Current ratings across the voltage range
The 3RH1122-1AU00's switching capacity varies with voltage: 10 A at 24 V, 6 A at 230 V, 3 A at 400 V, and 1 A at 690 V. At 110 V it's rated 1 A, at 220 V it drops to 0.27 A — these lower figures reflect the contact gap's ability to extinguish the arc at higher voltages. For a tire-curing press environment where control circuits run at 24 VDC or 230 VAC, the 10 A or 6 A rating respectively gives enough headroom for multiple solenoid valves or indicator lamps without paralleling contacts.
Mechanical endurance and environmental limits
Mechanical life is rated at 30 million operating cycles typical for the contactor size — that's a decade-plus of frequent cycling in a press control panel. Shock resistance is specified at 10g / 5 ms and 5g / 10 ms, which handles vibration from nearby motor starters or conveyor drives. Altitude limit is 2 000 m without derating; above that, air density reduction affects arc extinction. Storage and transport temperature range of -55 to +80 °C is broader than the operating range, so the part tolerates warehouse extremes.