Siemens SIRIUS 3RT1017-1BF41 Power Contactor — Size S00, 110 V DC Coil
The Siemens SIRIUS 3RT1017-1BF41 is a Size S00 power contactor designed for switching motor loads in control panels. It carries a 110 V DC coil and is rated for 5.5 kW at 400 V in AC-2 duty, making it a direct fit for standard three-phase motor circuits up to that power level. The 45 mm wide body snaps onto a 35 mm DIN rail per EN 50022, and the IP20 front enclosure keeps live parts protected inside a panel. The screw-type main terminals accept conductors up to 4 mm², with dual-wire capability for daisy-chaining.
Ratings and Coordination
For AC-4 duty (plugging/reversing) at 400 V the contactor is rated 8.5 A, and for AC-2 (slip-ring motor starting) it delivers 5.5 kW. The auxiliary contact block supports one instantaneous contact. Type 2 coordination requires a 20 A gL/gG fuse; Type 1 allows a 35 A fuse. The DC coil draws 3.3 W during both pick-up and hold, so the control transformer sizing is straightforward — no inrush surge beyond the steady-state power. Operating temperature range is -25 to +60 °C, and the unit is rated for pollution degree 3.