The Siemens 3RH2440-1BW40 is a SIRIUS auxiliary contactor in the compact S00 frame — 57.5 mm high, 90 mm wide, 73 mm deep — designed for screw and snap-on mounting onto a standard 35 mm DIN rail.
This auxiliary contactor carries 4 instantaneous normally-open (NO) contacts, rated for a thermal current of 10 A at both 24 V rated value and 230 V rated value. Switching capacity varies with voltage: at 60 V the rated value is 4.7 A, at 110 V it is 3 A, at 220 V it is 1.2 A, at 400 V it is 3 A, at 440 V it is 0.5 A, at 500 V it is 2 A, at 600 V it is 0.26 A, and at 690 V it is 1 A — so the contacts handle higher currents at lower control voltages and derate significantly above 400 V. Mechanical endurance is rated at 5,000,000 operating cycles typical for the contactor, with a maximum switching frequency of 10,000 operations per hour at AC and an arcing time of 10 to 15 ms.
Coil and environmental specs
The magnet coil draws 4 W closing power and 4 W holding power at DC. Operating temperature range is -25 to +60 °C, storage range is -55 to +80 °C, and relative humidity minimum is 10 % — suitable for unconditioned industrial enclosures.