The Siemens 3RH2344-1DE40-0KA0 is a SIRIUS auxiliary contactor in the S00 frame size, delivering four normally-open instantaneous contacts switched by a 24 VDC coil. The built-in varistor surge suppressor handles the coil's 4 W closing power at DC, so no external suppression diode is needed — one less component to track in the BOM.
Each NO contact is rated for 10 A at 24 V, 6 A at 230 V, and 3 A at 400 V. At 60 V the rating is 4.7 A; at 110 V it drops to 3 A; at 220 V it is 1.2 A. For higher voltages: 0.5 A at 440 V, 2 A at 500 V, 0.26 A at 600 V, and 1 A at 690 V. The arcing time spans 10 to 15 ms, with a mechanical life of 10 million operations typical and a maximum switching frequency of 10,000 operations per hour at AC. These ratings cover control-circuit isolation and signal switching across most industrial voltage levels — 24 VDC pilot devices, 120 VAC relay coils, and 400 VAC contactor coils all fall within the contact's capability.
The S00 frame (57.5 mm high, 45 mm wide, 117 mm deep) leaves clearance requirements: 10 mm upwards, 10 mm forwards, 10 mm downwards, and 6 mm at the side. Terminal capacity accepts 2 × (0.5 to 1.5 mm²), 2 × (0.75 to 2.5 mm²), or 2 × 4 mm² solid or stranded wire — sized for standard control-circuit terminations without special ferrules.