Auxiliary Contactor for Control Circuit Switching
The Siemens SIRIUS 3RH1122-1BE40 is a size S00 auxiliary contactor designed for switching control circuits, providing 2 normally open instantaneous contacts. Its 60 V DC coil draws a consistent 3.2 W for both closing and holding, simplifying power supply sizing in the panel. Rated for pollution degree 3 and surge voltage resistance of 6 kV, this contactor is built for industrial environments where transient overvoltages are common. The IP20 front protection means it is suitable for installation inside a locked enclosure or control cabinet.
Switching Capacity and Contact Reliability
The contact reliability specification states one incorrect switching operation per 100 million operations at 17 V, 1 mA, which is critical for PLC input or low-level signal switching where dry-circuit performance matters. The mechanical endurance is rated at 30 million switching cycles typical. Rated operational current varies 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. This derating curve reflects the arc extinction capability at higher voltages and must be respected when selecting the contactor for a given control voltage.
Mounting and Wiring Flexibility
The 3RH1122-1BE40 mounts via screw or snap-on onto a DIN rail, occupying 45 mm width, 57.5 mm height, and 72 mm depth. The mounting position allows ±180° rotation on a vertical surface and ±22.5° tilt forward/backward, giving panel builders flexibility in tight layouts. Terminals accept solid conductors: 2x 0.5–1.5 mm², 2x 0.75–2.5 mm², and 2x 4 mm². This covers most control wiring gauges used in industrial panels. The product extension for auxiliary switches is supported, allowing field addition of contact blocks.
Environmental and Compliance
Substance prohibition date per RoHS is 01.07.2006, confirming compliance with the original RoHS directive. The reference code per IEC 81346-2 is K, standard for contactors and relays in system documentation.