What this contactor is and where it fits
The Siemens 3RT2017-1XF42-0LA2 is a SIRIUS power contactor in size S00, designed for switching motor loads and resistive loads in industrial control panels. It carries a 72-125 V DC coil with screw-type terminals, and its main contacts are rated for 20-12 A depending on the duty class. The 45 mm width and 58 mm height let it snap onto a 35 mm DIN rail per DIN EN 50022, with 10 mm clearance needed above and below for arc dissipation.
Coil voltage and switching performance
The DC coil picks up at 70% of rated voltage (about 50 V on a 72 V nominal supply) and drops out at 125% of rated, so it holds in during brownouts down to roughly 50 V and releases cleanly when the control voltage rises above 90 V. Inrush current peaks at 1.1 A, and the operate time runs 25-45 ms with an arcing time of 10-15 ms. That arcing window matters for coordination with upstream fuses or breakers — the contactor clears the arc fast enough to avoid nuisance trips on a typical motor branch circuit.
Contact ratings across voltages
On DC loads, the contactor switches 10 A at 24 V, 2 A at 48 V or 60 V, 1 A at 110 V, 0.9 A at 125 V, and 0.3 A at 220 V. For AC motor duty at 230 V it handles 2 hp, and at 480 V it switches 11 A. The AC-4 maximum switching rate is 250 operations per hour, which covers frequent jogging or inching applications. Mechanical life is rated at 30 million operations, so the contactor outlasts most panel builds.
Wiring and mounting
Screw terminals accept solid or stranded wire: 2x 0.5-1.5 mm², 2x 0.75-2.5 mm², or 2x 4 mm². The contactor mounts via screw or snap-on onto a 35 mm DIN rail. Mounting position is flexible — ±180° rotation on a vertical surface, ±22.5° tilt forward/backward, or standing on a horizontal surface. Side clearance is only 6 mm, so you can pack multiple units tight in a row. Operating temperature range is -40 to +70 °C; storage goes from -55 to +80 °C.