The contactor is rated for 37 kW at 500 V and 18.6 kW at 690 V in AC-3 duty, which is the standard category for squirrel-cage motor starting — that rating tells you the maximum motor load it can switch under full load without accelerated contact wear.
Side-by-side mounting is permitted, which saves panel width when grouping multiple contactors. The S3 frame occupies 70 mm width, 146 mm height, and 139 mm depth — check your gland plate clearance before committing the layout.
Screw-type terminals on the main current circuit accept solid conductors from 2x (0.5... 1.5 mm²) up to max 2x (0.75... 4 mm²), and stranded conductors from 2x (10... 50 mm²). The auxiliary circuit accepts 2x (2.5... 16 mm²) solid or stranded. That range covers most motor branch circuit wiring up to the 37 kW rating — no need for terminal adaptors unless you're landing aluminum conductors.
Environmental and protection ratings
Front of the contactor carries IP20 protection — safe against finger contact with live parts inside the enclosure. The terminal area itself is rated IP00, meaning it relies on the panel enclosure for touch protection.
Switching performance and life
Maximum switching rates vary by duty: 1000 cycles per hour in AC-1 (resistive) and AC-3 (motor start/run), 400 in AC-2 (slip-ring motor), and 300 in AC-4 (plugging/inching). These numbers matter for coordination with upstream protection — the contactor clears fast enough that a downstream short won't weld the main contacts if the breaker opens within a few cycles.