What this contactor is and what it does
The Siemens 3RT1017-1BE42 is a SIRIUS power contactor in the compact Size S00 frame, built for switching motor loads and resistive loads in control panels. It snaps onto a 35 mm DIN rail per DIN EN 50022 and uses screw-type terminals for the main circuit. The 24 VDC coil draws 3.3 W to close and holds at 3.3 W — no AC ripple to filter, which simplifies the control transformer sizing. Rated for AC-3 duty at 5.5 kW on 400 V, it handles three-phase induction motors up to that load. The same contactor also carries 5.5 kW at 690 V in AC-3, so it works across 400 V and 690 V line voltages without a frame size bump. For resistive loads (AC-1), the maximum operating current is 10 A at 24 V.
Key ratings and what they mean for your panel
The 45 mm width and 57.5 mm height let it fit tightly on a DIN rail — side-by-side mounting is allowed with 6 mm clearance to adjacent devices for heat dissipation. Depth is 72 mm, which matters when the gland plate is close. The IP20 finger-safe terminals on the front and at the terminal points mean you can work in a live panel with basic PPE, but the contactor itself is not sealed against dust ingress — it belongs inside an enclosure. Short-circuit coordination is specified: Type 2 coordination requires a gL/gG 20 A fuse upstream; Type 1 coordination allows a 35 A fuse. That lets the panel designer pick the fuse size based on whether they want the contactor to survive a fault (Type 2) or just clear it (Type 1).
Termination and wiring notes
Screw terminals accept solid or stranded copper: 2x (0.5 to 1.5 mm²), 2x (0.75 to 2.5 mm²), and up to 2x (0.75 to 4 mm²) maximum. AWG equivalents are 2x (20 to 16), 2x (18 to 14), and 1x 12. The contactor is rated for pollution degree 3, so it tolerates the conductive dust and humidity typical of industrial enclosures without conformal coating.