What this contactor is and what it does
The Siemens 3RT2037-1AP00-1AA0 is a SIRIUS power contactor in size S2, rated for 65 A at 480 V in AC-3 duty — that's the motor-switching rating, so it handles starting and running loads for motors up to that current without welding the contacts on inrush. It mounts on a 35 mm DIN rail per DIN EN 60715, using either the screw or snap-on method, and sits in a standing position on a horizontal surface — typical for a control panel backplane. The coil and main contacts use screw-type terminals, accepting solid or stranded wire from 0.5 to 2.5 mm² (two conductors per terminal).
What the ratings mean for fit
The 65 A at 480 V AC-3 rating is the one that governs motor switching — it's not the resistive (AC-1) rating, which would be higher. If your motor full-load current is under 65 A at 480 V, this contactor has headroom for starting current without derating. Mechanical life is typical at 10 million operations, and the maximum switching frequency ranges from 200 cycles/hour in AC-4 (plugging/inching) up to 800 cycles/hour in AC-1 (resistive), so it's built for continuous-duty cycling, not just on-off. The auxiliary switch is included, saving a separate add-on block for feedback or status indication in the control circuit.
Panel integration notes
Dimensions are 55 mm wide, 114 mm high, 130 mm deep — size S2 footprint. Clearance around the contactor: 10 mm upwards, forwards, and downwards, and 6 mm at the sides. That matters for heat dissipation and arc-chamber venting. Operating temperature range is -25 to +60 °C; storage range is -55 to +80 °C. If the panel ambient exceeds 60 °C, you'll need to derate or force-ventilate.