Size S00 contactor with a built-in auxiliary switch
The Siemens 3RT2517-1BF40 is a SIRIUS contactor in the compact Size S00 frame, meaning it fits the 45 mm width slot common in high-density panel layouts where every DIN-rail millimeter is accounted for. It ships with an integrated auxiliary switch, so you don't need a separate side-mount block for basic status feedback or interlocking — one less part to stock and one less terminal to wire. The coil is rated at 110 V AC, a standard control voltage in many industrial installations, with a pickup threshold of 0.8 x rated value and a dropout of 1.1 x full-scale value.
Auxiliary contact ratings across the voltage range
At 110 V AC — the coil voltage of this contactor — the auxiliary contacts carry 1 A, so confirm the downstream load current stays under that limit if you're using the same supply rail for both coil and feedback.
Mounting flexibility and panel clearances
Zero clearance is required upwards, forwards, backwards, and downwards (–), so you can butt it against other devices on the rail without derating. Only 6 mm side clearance is needed for heat dissipation.
Termination and wiring capacity
Both the main current circuit and the magnet coil use screw-type terminals — a field-serviceable choice that doesn't require special crimp tools.