Siemens 3RH1344-1DF40-0KA0 — SIRIUS Auxiliary Contactor, 110 V DC Coil, 4 NO
The Siemens 3RH1344-1DF40-0KA0 is a SIRIUS auxiliary contactor in size S00, designed for switching control and signal circuits in industrial panels. It carries 4 instantaneous normally-open contacts rated at 10 A at 24 V, 6 A at 230 V, and 1 A at 690 V — so it handles 24 VDC PLC outputs and 230 VAC pilot duty on the same block. The 110 V DC coil draws 3.2 W closing and holding, with pickup at 0.8x rated and dropout at 1.1x rated. Mounting is via screw and snap-on onto DIN rail; the 45 mm width fits standard S00 contactor spacing.
Contact Ratings and Duty
The four NO contacts are rated for inductive and resistive loads across common control voltages: 10 A at 24 V (DC-13 typical for solenoid valves and contactor coils), 6 A at 230 V (AC-15 pilot duty), 3 A at 400 V, 2 A at 500 V, and 1 A at 690 V. The mechanical life is rated at 10 million operations, and contact reliability is specified as one incorrect switching per 100 million at 17 V, 1 mA — adequate for dry-circuit signal switching in PLC input chains.
Environmental and Mounting
Rated for operation from -25 °C to +60 °C, storage and transport from -55 °C to +80 °C. Pollution degree 3 (conductive pollution or dry non-conductive that becomes conductive). The front face carries IP20 protection — finger-safe terminal access, but not for washdown. Shock resistance is 10g for 5 ms and 5g for 10 ms. Mounting position allows ±180° rotation on a vertical surface and ±22.5° tilt forward/backward, so it fits tight panel layouts without derating. The varistor surge suppressor is built in across the coil, rated for 6 kV surge voltage — no external suppression needed for most 110 V DC circuits.