SIRIUS S00 power contactor — 24 VDC coil, spring-loaded terminals
The Siemens 3RT1017-2MB42-0KT0 is a SIRIUS-branded power contactor in the compact S00 frame size, designed for screw and snap-on mounting onto 35 mm DIN rail per EN 50022. It carries a 24 VDC coil with a holding power of 1.4 W, and its main circuit uses spring-loaded terminals accepting 2x (0.25 to 2.5 mm²) solid or stranded wire. For motor switching duty, the contactor is rated 8.5 A at AC-4 at 400 V — that's the full reversing or plugging current, not just the running load. The AC-12 resistive rating goes up to 10 A. At 24 VDC the coil draws its closing and holding power at 1.4 W, so the control transformer can be sized lean.
Mounting and panel fit
The S00 footprint is 45 mm wide by 60 mm tall by 73 mm deep. It clips onto 35 mm DIN rail per DIN EN 50022 and also accepts screw mounting. Side-by-side mounting is allowed with 6 mm spacing at the side for heat dissipation. IP20 finger-safe protection on the front and terminals means it can sit in a standard IP54 enclosure without additional shrouding.
Coordination and protection
For type 2 coordination (no damage to the contactor on short circuit), the required upstream fuse is gL/gG 20 A. For type 1 coordination (contactor may need replacement after fault), use a 35 A gL/gG fuse. The pollution degree is 3, suitable for industrial environments with conductive dust or condensation. Operating temperature range is -25 to +60 °C, with altitude limit of 2,000 m.