SIRIUS S00 power contactor — 4 NO, spring-loaded, DIN-rail
The Siemens 3RT1316-2BP40 is a SIRIUS S00 power contactor with four normally-open main contacts and zero normally-closed main contacts — a straight 4-pole NO configuration for switching resistive or motor loads where no NC pole is needed in the main circuit. Rated for AC-2 duty at 4 kW on 400 V three-phase, this contactor handles wound-rotor motor starting and reversing applications where the AC-2 category applies (starting and plugging duty). The spring-loaded terminals accept 2x (0.25 to 2.5 mm²) solid or stranded conductors, or 2x (0.25 to 1.5 mm²) finely stranded with ferrule — no screw torque to verify, which speeds panel wiring. Mounts via screw or snap-on onto 35 mm DIN rail per EN 50022, with 6 mm side clearance for side-by-side mounting. The S00 footprint (45 mm wide, 60 mm tall, 72 mm deep) packs into tight sub-panel layouts.
Coordination and protection
For Type 2 coordination (no damage to the contactor under short-circuit), Siemens specifies a 20 A gL/gG fuse upstream. Type 1 coordination allows a 35 A gL/gG fuse, where the contactor may need replacement after a fault but the installation stays intact. The DC magnet coil draws 3.3 W holding power — continuous-duty rated, no economizer resistor needed. Coil operating range is 0.85 to 1.1 x rated voltage (230 V coil version). Rated for pollution degree 3 (industrial environment with conductive pollution), with IP20 finger-safe protection on the front and terminals.
Environmental and mechanical endurance
Operating ambient -25 to +60 °C, with altitude derating above 2000 m. Mechanical life rated at 30 million operating cycles typical.