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.
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. The storage limit covers handling and shipping, not running conditions.
Switching performance and mechanical life
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.