It carries a 37 kW rating at 500 V and 18.6 kW at 690 V, so it handles medium-horsepower induction motors in pumps, fans, and compressors up to that power range. Mounts on 35 mm or 75 mm standard DIN rail via screw and snap-on fastening, and side-by-side mounting is permitted — no gap needed between units in a dense panel layout. The main current circuit uses screw-type terminals, accepting stranded conductors up to 2x 50 mm² and solid conductors from 0.5 mm² up to 4 mm² on the control side. That covers most panel wiring from signal-level through motor feeders.
Rated 37 kW at 500 V (AC-3 duty) and 18.6 kW at 690 V — those are the motor-switching numbers that govern real-world load selection. AC-1 (resistive) and AC-4 (plugging/inching) ratings are lower, so don't size this contactor by the AC-1 figure if you're switching motor loads. The -25 °C low end means it starts reliably in cold plant conditions or unheated enclosures; the +60 °C ceiling accommodates panels near furnaces or in hot climates without derating the thermal curve. Front protection is IP20 with cover or box terminal; the terminal itself is IP00. That's standard for panel-mounted contactors — the IP20 front keeps fingers off live parts once the enclosure door is closed, but the terminals themselves need enclosure protection.
DIN Rail Integration and Panel Fit
At 70 mm wide, 146 mm tall, and 139 mm deep, the S3 frame fits a standard DIN-rail footprint. The 139 mm depth is the critical dimension for enclosure depth selection — make sure your cabinet has at least 150 mm clear depth behind the rail to accommodate wiring and bending radius on the screw terminals. Snap-on mounting onto 35 mm or 75 mm rail means no tools needed for installation or removal — useful for panel builders who need to swap units during commissioning without disturbing adjacent wiring.