What this contactor is and where it fits
The Siemens 3RT2037-1NF34 is a SIRIUS power contactor in size S2, built for switching motor loads and resistive loads in control panels. It mounts via screw or snap-on onto 35 mm standard mounting rail per DIN EN 60715, so it drops into any standard DIN-rail enclosure without extra bracketry.
Coil voltage and switching capacity
The coil accepts 83-155 V AC/DC, with a 1.5 A inrush peak at pickup. At 24 V rated value it switches 6 A; at 48 V and 60 V it handles 2 A; at 110 V it's rated 1 A; at 125 V it's 0.9 A; at 220 V it's 0.3 A. That spread covers most control-voltage standards in European and North American panels.
Mechanical and electrical endurance
Mechanical life is typically 10,000,000 operations. Electrical life varies by duty: AC-1 (resistive) allows up to 800 operations per hour, AC-3 (motor starting) up to 700 ops/h, AC-4 (plugging/reversing) up to 200 ops/h. Arcing time runs 10-20 ms; the contactor's own switching frequency limits are what govern real-world panel duty cycles.
Mounting and clearances
Dimensions are 114 mm high, 55 mm wide, 174 mm deep. Minimum clearances: 10 mm upwards, 10 mm forwards, 10 mm downwards, 6 mm at the side. The mounting position allows +/-180° rotation on a vertical surface and +/-22.5° tilt forward/backward, so it fits tight enclosures where the rail orientation isn't ideal.
Environmental range and wiring
Operating temperature is -25 to +60 °C; storage range is -55 to +80 °C. The magnet coil uses screw-type terminals accepting 2x (0.5-1.5 mm²) or 2x (0.75-2.5 mm²) solid or stranded wire. No auxiliary switch is included on this variant — if you need aux contacts, plan for a separate block.