The Siemens 3RT1017-2KB41 is a SIRIUS S00 power contactor rated for switching motor loads. Its 24 VDC coil draws 2.3 W during closing and holding, so the control transformer or PLC output must supply that continuously — no inrush peak to worry about, but the steady load is there. Spring-loaded terminals on both main and auxiliary circuits accept 2x (0.25 to 2.5 mm²) solid/stranded or 2x (24 to 14 AWG), which saves a screwdriver step during panel wiring.
Motor duty and coordination
At AC-2 duty (slip-ring motors, wound-rotor) the contactor handles 5.5 kW at 400 V. For AC-4 (plugging, inching) the rated operational current is 8.5 A at 400 V — that is the figure to size for reversing or jogging applications. Type 2 coordination requires a 20 A gL/gG fuse; Type 1 allows 35 A. The built-in varistor surge suppressor clips coil transients, so no external RC snubber is needed for the magnet coil.
Integration and environment
Mounts via screw or snap-on onto 35 mm DIN rail per EN 50022. The S00 frame is 45 mm wide, 60 mm tall, 73 mm deep — a compact footprint that leaves room for adjacent devices. Side-by-side mounting is allowed without derating, which simplifies multi-contactor motor starter assemblies. IP20 on the front and terminals means it is suited for enclosure use only; no washdown or outdoor exposure without a separate enclosure. Operating temperature range is -25 to +60 °C, with pollution degree 3 (conductive pollution typical in industrial panels).