What it is and what it does
The Siemens 3RT1017-1AS01 is a SIRIUS power contactor in the compact S00 frame size, designed for switching motor and resistive loads in control panels. It carries a 24 VDC coil and offers screw-type terminals for both main and auxiliary circuits. The contactor mounts on a 35 mm DIN rail per DIN EN 50022, either snapped on or screwed, and can be mounted side-by-side without derating. The auxiliary contact block is rated at 10 A at 24 V, 6 A at 230 V, and 3 A at 400 V, covering the typical control-circuit voltages found in industrial panels. For motor switching under AC-4 duty (frequent starting and reversing), it is rated at 8.5 A at 400 V, which is the rating that governs real-world service life when the contactor sees heavy inching or plugging.
Mounting and wiring constraints
The contactor occupies a 45 mm width on the DIN rail, with a height of 57.5 mm and a depth of 72 mm — a footprint that fits standard 45 mm-wide panel cutouts and leaves room for adjacent devices. Screw terminals accept 2x (0.5 to 1.5 mm²) solid or stranded, 2x (0.75 to 2.5 mm²), or up to 2x (0.75 to 4 mm²) for the main circuit; auxiliary terminals accept the same range. AWG equivalents are 2x (20 to 16), 2x (18 to 14), or 1x 12. The enclosure is rated IP20 on the front and at the terminals, so it is intended for installation inside a panel that provides a higher overall enclosure rating. Operating temperature range is -25 to +60 °C, with a pollution degree of 3, meaning it is suited for industrial environments with conductive dust or occasional condensation inside the panel.
Coordination and protection
For short-circuit protection, the manufacturer specifies a gL/gG fuse of 20 A for Type 2 coordination (no damage to the contactor) and 35 A for Type 1 coordination (contactor may need replacement after a fault). These fuse ratings should be reflected in the panel BOM.