Panel fit and mounting
The 3RT2037-1AG20: Mounts via screw and snap-on onto 35 mm DIN rail per DIN EN 60715. Dimensions: 55 mm wide, 114 mm tall, 130 mm deep. The 55 mm width occupies three standard 18 mm DIN-rail module slots, which matters when you are packing contactors into a crowded panel. Mounting position is flexible: ±180° rotation on a vertical surface, and can be tilted forward/backward ±22.5° on a vertical surface. Clearance requirements: 10 mm upwards, 10 mm forwards, 10 mm downwards, 6 mm at the side.
Duty-cycle and switching frequency
Switching frequency depends on the duty category: AC-1 (resistive) allows up to 800 operations per hour; AC-3 (motor start/run) allows 700 per hour; AC-2 (slip-ring motor) allows 400 per hour; AC-4 (plugging/inching) allows 200 per hour. The AC-3e maximum is also 700 1/h. Arcing time is 10–20 ms; closing time is 10–18 ms. These numbers define the thermal cycling limit for a given application — exceeding them accelerates contact wear.
Auxiliary contact ratings
The built-in auxiliary switch is rated for switching at various control voltages: 10 A at 24 V, 2 A at 48 V, 2 A at 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. The main contact configuration is 18 normally open contacts. Wire termination: screw-type terminals accepting 2x (0.5–1.5 mm²) or 2x (0.75–2.5 mm²) solid or stranded.