SIRIUS S0 power contactor — 27 A at 480 V AC-3
The Siemens 3RT2027-2EP00 is a SIRIUS S0 power contactor rated 27 A at 480 V in AC-3 duty, meaning it handles motor switching up to that current without welding the main contacts under locked-rotor inrush. The coil termination uses spring-type terminals; the main and auxiliary circuits accept solid or stranded conductors from 1 to 10 mm², with a separate 2x (0.5 to 2.5 mm²) range for the auxiliary contacts. A built-in auxiliary switch block provides 1 normally-open and 1 normally-closed contact — enough for a feedback signal to a PLC or to seal in the holding circuit without an add-on block.
Panel integration and mounting
Mounts via screw or snap-on onto 35 mm DIN rail per DIN EN 60715. The S0 frame is 45 mm wide, 102 mm tall, 97 mm deep — standard for a 3-pole contactor in this class, so it fits existing S0 cutouts and rail spacing. Clearance requirements: 10 mm upwards, 10 mm forwards, 10 mm downwards, and 6 mm at the side. The mounting position allows ±180° rotation on a vertical surface and ±22.5° tilt forward/backward — useful when panel layout forces an unconventional orientation. Operating temperature range -25 to +60 °C; storage range -55 to +80 °C. The storage limit covers handling and shipping, not running conditions.
Switching performance and mechanical life
Mechanical life is rated at 10 million operations typical — a figure that assumes no electrical load on the contacts. Electrical life depends on duty: 1 000 000 cycles at AC-1 (resistive), 750 000 at AC-2 and AC-3 (motor starting), and 250 000 at AC-4 (plugging/inching). Arcing time is 10 ms at 50 Hz, with an arcing distance of 10 mm. The coil pick-up and drop-out times at AC are 4 to 16 ms.