SIRIUS contactor, size S0, for DC switching
The Siemens 3RT2327-2BG40 is a SIRIUS contactor in size S0, designed for DC load switching with a 125 VDC coil and spring-type terminals on the magnet coil. It fastens via screw or snap-on mounting onto 35 mm DIN rail per DIN EN 60715, and the mounting position allows +/-180° rotation on a vertical surface plus +/-22.5° tilt forward/backward — useful when panel layout forces an unconventional orientation. DC switching ratings span 10 A at 24 V, 6 A at 60 V, 2 A at 48 V, 1 A at 110 V, 0.9 A at 125 V, 0.3 A at 220 V, 3 A at 400 V, 2 A at 500 V, and 0.1 A at 600 V — the 10 A at 230 V entry likely reflects an AC rating or a different duty condition. The main contacts are rated for 18 A (make) and 8 A (break) in the DC-1 duty class, which covers resistive loads. For inductive DC loads, derate further based on the load time constant. Coil operates at 125 VDC with an 0.8x initial pickup threshold and 1.1x full-scale tolerance. Operating times: 15–18 ms closing (at DC), 10–10 ms arcing. The auxiliary switch is present (2-pole, normally open/closed configurable). Conductor cross-sections: solid 2x (0.5–2.5 mm²) or stranded 1–10 mm² for the main circuit.
Mounting and clearances
Dimensions: 102 mm high, 60 mm wide, 107 mm deep. Required clearances: 10 mm upwards, 10 mm forwards, 10 mm downwards, 6 mm at the side. The 107 mm depth is the full body depth including coil terminals — ensure the DIN rail has enough rear clearance for the spring-cage mechanism to engage without obstruction. Operating temperature range -25 to +60 °C; storage -55 to +80 °C. The contactor is rated for 10 million mechanical operations typical.