The Siemens SIRIUS 3RH1140-1MB40 is a coupling relay — a compact auxiliary contactor designed to switch control and signal circuits in a panel. Its 24 V DC coil pulls in at 85 % of rated voltage and drops out at 215 % of rated voltage, giving a clean pick-up and dropout margin for PLC or safety-relay outputs. It carries four normally-open instantaneous contacts (no delayed or leading/lagging switching), rated at 10 A at 24 V, 6 A at 230 V, and 3 A at 400 V — enough for pilot lamps, contactor coils, solenoid valves, and small motor contactor auxiliaries.
The S00 frame size (45 mm wide, 57.5 mm tall, 72 mm deep) fits the standard DIN-rail footprint and can be screw-mounted or snapped onto the rail. Terminals accept 2x (0.5…1.5 mm²), 2x (0.75…2.5 mm²), or 2x 4 mm² solid/stranded, with AWG equivalents at 2x (20…16), 2x (18…14), and 1x 12. The IP20 front protection keeps fingers out during live maintenance.
No allocation pressure expected on this 24 V DC variant.
The part is RoHS-compliant per the substance prohibition date of July 1, 2006.