Integrator's terse spec recap
The Siemens SIRIUS 3RT2027-2XB40-0LA2 is a Size S0 power contactor with a 24 V DC coil and spring-type terminals on the coil. It mounts via screw or snap-on onto 35 mm DIN rail per DIN EN 60715. The main contacts are rated for AC-3 switching at up to 750 operating cycles per hour, with AC-4 limited to 250 cycles/h. An auxiliary switch is built in, rated for 10 A at 24 V DC, derating to 0.3 A at 220 V DC. Mechanical life is 10 million operations typical.
Mounting and integration
Panel integration is straightforward: the contactor snaps onto a 35 mm DIN rail (DIN EN 60715) or can be screw-mounted. The mounting position allows +/-180° rotation on a vertical surface and can be tilted forward/backward by +/-22.5° on a vertical surface. Clearance distances: 10 mm upwards, 10 mm forwards, 10 mm downwards, 6 mm at the side. Dimensions are 102 mm high, 45 mm wide, 107 mm deep — the standard S0 footprint.
Wiring practice note
Main contact terminals accept solid conductors 2x (1... 10 mm²) or stranded 2x (0.5... 2.5 mm²). The coil uses spring-type terminals — no screw torque to verify, but ensure the stripped length is correct for the cage clamp. Inrush current peak is 3 A at 24 V DC coil pickup. Arcing time is 10... 10 ms; for DC switching, the arc extinguishes in 30... 50 ms. Operating temperature range is -40 to +70 °C, storage -55 to +80 °C.