Main contact and auxiliary contact ratings
The 3RT2337-1AL20: The main contacts are rated for AC-3 duty with a range from 18 A down to 1 A, covering the common motor sizes you'd see on pumps, fans, and small conveyors out in the plant. The S2 frame is the physical envelope — it tells you the mounting hole pattern and the busbar spacing you'll need in the panel. That means the same aux block works across 24 V PLC outputs and 230 V pilot circuits without swapping contacts. Coil pick-up time is 10 to 18 ms AC, and the arcing time on dropout is 10 to 20 ms — numbers that matter when you're coordinating with upstream protection or sequencing multiple contactors in a star-delta start.
Environmental tolerance and wiring
The coil draws 0.36 A at 50 Hz and 0.39 A at 60 Hz, a small enough difference that the same control transformer handles both. The screw-type terminals are the standard industrial choice — reliable under vibration, no special tooling needed on the line. Clearance spacing: 10 mm upwards and forwards, 6 mm at the sides, 10 mm downwards. That's the minimum air gap to adjacent metalwork or other contactors — stick to it and you avoid arc flash tracking between phases.