SIRIUS S2 power contactor — 3RT2037-1AH24
The Siemens 3RT2037-1AH24 is a SIRIUS-brand power contactor in the S2 frame size, designed for screw and snap-on mounting onto 35 mm DIN rail per DIN EN 60715. It carries a 65 A rating at 480 V — the headline motor current figure that governs most selection decisions for this frame. Dimensions are 174 mm deep, 55 mm wide, and 114 mm tall, fitting into standard panel layouts with the S2 footprint. Mounting position allows +/-180° rotation on a vertical surface and +/-22.5° tilt forward/backward, giving flexibility in tight enclosures. Clearance requirements: 10 mm upward, 10 mm forward, 10 mm downward, and 6 mm at the side — plan your gland plate and wireway spacing accordingly.
Duty ratings and switching performance
Switching rates vary by duty class: AC-1 (resistive) at 800 operations/hour max, AC-3 (motor start/run) at 700 ops/h, AC-2 at 400 ops/h, and AC-4 (plugging/inching) at 200 ops/h. The AC-3e rating also sits at 700 ops/h. These limits define the thermal cycling the contactor can sustain without accelerated wear. Arcing time spans 10 to 20 ms; operate time (AC) is 10 to 18 ms. The main contact configuration is 18 normally open contacts, 1 normally closed — typical for a three-pole power contactor with an auxiliary N/C. Coil termination uses screw-type terminals. The magnet coil connection accepts 2x (0.5 to 1.5 mm²) or 2x (0.75 to 2.5 mm²) solid or stranded wire.
Environmental and lifecycle
Operating temperature range is -25 to +60 °C; storage range extends from -55 to +80 °C. The contactor is rated for a typical mechanical life of 10,000,000 operations.
Auxiliary contact and voltage ratings
This variant ships without an auxiliary switch block — the auxiliary switch field is marked 'No'. If your circuit requires early-make or late-break aux contacts, they must be added as separate modules. Auxiliary contact current ratings at various control voltages: 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. At 50 Hz the rated control supply voltage is 48 V.