What it is and what it does
The Siemens 3RT2017-2WB42 is a SIRIUS coupling contactor in size S00, designed for switching DC loads up to 10 A at 24 V rated value. It uses a 24 VDC magnet coil with spring-type terminals for the coil connection, and it carries no built-in auxiliary switch — you add aux contacts separately if needed. Rated operating current drops with voltage: 2 A at 48 V or 60 V, 1 A at 110 V, 0.9 A at 125 V, 0.3 A at 220 V, and 3 A at 400 V. At 230 V the contactor is rated for 2 hp motor load. These are the DC switching limits — for AC motor duty, use the AC-3 rating. Mechanical life is typical 30 000 000 operations. Electrical life depends on load: at AC-1 maximum 1 000 1/h, at AC-2 and AC-3 maximum 750 1/h, at AC-4 maximum 250 1/h. The arcing time is 10 to 15 ms.
Mounting and wiring constraints
Mounts on 35 mm DIN rail per DIN EN 60715, using screw and snap-on fastening. The contactor is 45 mm wide, 70 mm high, 121 mm deep — that depth matters when you're laying out gland plates or door clearance. Clearance around the part: 10 mm upwards, 10 mm forwards, 10 mm downwards, and 6 mm at the side. Wire range: solid or stranded 0.5 to 4 mm², or 2x (0.5 to 4 mm²) for paralleled conductors. The magnet coil uses spring-type terminals — no screw tightening, just push in. Operating temperature range is -25 to +60 °C; storage range is -55 to +80 °C. Mounting position is flexible: +/-180° rotation on a vertical surface, and can be tilted forward/backward by +/-22.5° on a vertical surface. That helps when you're fitting it into a crowded panel.