Auxiliary contactor for control-circuit switching
The Siemens 3RH1140-1AM20 is a SIRIUS auxiliary contactor in size S00, carrying 4 normally-open instantaneous contacts for switching control loads in a panel. It mounts via screw or snap-on onto DIN rail, with a 45 mm width footprint that fits standard enclosure rail spacing. Rated surge voltage resistance is 6 kV, and the front face carries IP20 protection — safe for finger-probe access inside a closed panel.
Contact ratings and switching reliability
The contacts are rated for 10 A at 24 V, 6 A at 230 V, 3 A at 400 V, and 1 A at 690 V — covering the common control-voltage levels in industrial AC circuits. At 50 Hz the rated operational voltage is 208 V; at 60 Hz it is also 208 V. The contactor is designed for both 50 Hz and 60 Hz systems. Contact reliability is specified as one incorrect switching operation per 100 million switching operations at 17 V, 1 mA — useful for low-energy signal circuits where oxide film on silver contacts can cause intermittent opens.
Environmental and mechanical limits
Operating temperature range is -25 to +60 °C; storage and transport range extends to -55 to +80 °C. Pollution degree 3 means it tolerates conductive pollution typical in industrial enclosures. Shock resistance is 10g for 5 ms and 5g for 10 ms. The mounting position allows ±180° rotation on a vertical surface and ±22.5° tilt forward/backward — flexible for tight panel layouts. Mechanical endurance is rated at 30 million operating cycles typical for the contactor.
Termination and wiring
The solid terminals accept 2x (0.5 to 1.5 mm²), 2x (0.75 to 2.5 mm²), or 2x 4 mm² conductors — spring-cage or screw-clamp depending on variant; this order code uses screw terminals. Dimensions are 45 mm wide, 57.5 mm high, and 72 mm deep. The depth is the key clearance dimension when wiring behind the contactor on a DIN rail.
Lifecycle and compliance
Substance prohibitance (RoHS) compliance date is July 1, 2006, covering the EU RoHS directive. The product carries the SIRIUS brand designation.