Panel fit and wiring
The 3RT1017-2KF41 is a Size S00 power contactor from the Siemens SIRIUS family, built for switching motor loads in control panels. It mounts on 35 mm DIN rail per DIN EN 50022 using either screw or snap-on fastening, and its 45 mm width means it occupies a single modular slot — important when you're packing multiple contactors into a tight enclosure. The IP20 rating on the front and terminals means it's protected against finger contact but expects to live inside a panel, not out in a washdown zone. Spring-loaded terminals on main and control circuits accept 2x (0.25... 2.5 mm²) solid or stranded wire, and 2x (24... 14) AWG for aux contacts.
Motor switching and coordination
Rated for AC-3 duty at 5.5 kW on both 400 V and 690 V supplies, this contactor handles the standard induction motor starting profile — high inrush on close, break at running current. For the heavy plugging and inching duty of AC-4 at 400 V, it's rated 8.5 A, which is the figure that governs frequent reversing or jogging applications. The 110 VDC coil pulls 2.3 W on close and holds at 2.3 W — a constant-power DC coil, so no holding-current drop to worry about. Type 2 coordination (the standard for most industrial panels) requires a 20 A gL/gG fuse upstream; Type 1 coordination allows a 35 A fuse. That's the short-circuit protection the contactor needs to survive a fault without welding its contacts or bursting the arc chamber. Side-by-side mounting is permitted, which means no derating for zero-gap packing in a multi-contactor group.
Coil and auxiliary circuit
The coil includes a built-in varistor as the surge suppressor, which clips the inductive kickback when the DC coil de-energizes. That's important if the coil is driven by a PLC output or a solid-state relay — without the varistor, the flyback voltage can exceed the semiconductor's breakdown rating. The auxiliary contact ratings cover the usual control voltages: 10 A at 24 V, 6 A at 230 V, 3 A at 400 V, and 1 A at 110 V (the coil voltage itself). Operating temperature range is -25 to +60 °C, which covers most indoor panel environments including unheated warehouses. Pollution degree 3 means it's rated for the conductive-dust and humidity conditions typical of industrial floors — not clean-room, but not sealed either.