What it is and what it does
The Siemens 3RT2037-1AF04 is a SIRIUS power contactor in size S2, designed for switching motor loads in industrial control panels. It carries a 65 A rated value at 480 V and a 10 hp rating at 230 V, which defines its motor-switching capacity under typical North American and European line voltages. The coil is screw-type terminals, and the main contacts are rated for 18 to 1 A range, covering a broad band of motor FLA.
Mounting and integration
Mounts via screw and snap-on onto 35 mm DIN rail per DIN EN 60715. The mounting position allows +/-180° rotation on a vertical surface and can be tilted forward/backward by +/-22.5° on a vertical surface, giving flexibility in tight enclosures. Clearance distances: 10 mm upwards, forwards, and downwards; 6 mm at the side. Dimensions are 55 mm wide, 114 mm high, 174 mm deep — a compact S2 footprint for a 65 A contactor.
Switching frequency and thermal limits
Switching frequency varies by duty: AC-1 (resistive) max 800 operations/hour, AC-2 (slip-ring motor) 400 ops/h, AC-3 (squirrel-cage motor) 700 ops/h, AC-4 (plugging/inching) 200 ops/h, and AC-3e (enhanced AC-3) also 700 ops/h. Operating temperature range is -25 to +60 °C, storage -55 to +80 °C. Arcing time is 10 to 20 ms; at AC it's 10 to 18 ms.
Auxiliary contact ratings and wiring
This variant ships without an auxiliary switch block. The auxiliary contact ratings are given per voltage: 6 A at 24 V, 2 A at 48 V and 60 V, 1 A at 110 V, 0.9 A at 125 V, 0.3 A at 220 V, 3 A at 400 V, 0.6 A at 440 V, 2 A at 500 V. Wire capacity: 2x (0.5 to 1.5 mm²) or 2x (0.75 to 2.5 mm²) solid or stranded. Mechanical life is typical 10,000,000 operations.