Siemens 3RT1017-1BB42 Contactor

Siemens 3RT1017-1BB42 is a 3-pole Sirius power contactor rated for AC-3 operation at 400 V, delivering 5.5 kW (about 7.5 HP) to a motor and featuring three normally open main contacts plus one normally closed auxiliary contact (1 NC). The coil is a 24 V DC control input, with a main-circuit current rating of 12 A at AC-3/400 V and 8.5 A at AC-4/400 V, making it suitable for switching small-to-mid-size three-phase motors in industrial panels. Encased in the compact S00 frame, it uses screw-terminal connections for robust wiring, and front IP rating of IP20 for basic protection. Applications include conveyors, pumps, fans, and general machine automation where a compact, reliable motor-start solution is required. This specific 3RT1017-1BB42 variant pairs 3 NO main contacts with a single NC auxiliary contact, enabling feedback or interlock signaling in control circuits, and is part of Siemens Sirius line known for dependable performance in motor control tasks.