The Siemens SIRIUS 3RT1034-3AP04-1AA0 is a size S2 power contactor built for switching motor loads in industrial control panels. It's rated 18.5 kW at 500 V in AC-3 duty, and 10 kW at 690 V — so it handles standard 400 V motors comfortably, and has headroom for 690 V applications where you're running a motor on a higher-voltage line. The screw-type terminals on the main circuit accept up to 16 mm² stranded wire, which is enough for the full rated current without needing to parallel cables.
Mounts on a 35 mm DIN rail per EN 50022, with a screw-and-snap-on fastening method — no tools needed to clip it on, but the screw adds security in high-vibration environments. At 55 mm wide and 112 mm tall, it takes up one standard DIN module width. Side-by-side mounting is allowed, so you can pack multiple contactors in a row without a gap.
Rated for pollution degree 3, meaning it's built for industrial environments where conductive dust or condensation can occur. The front carries IP20 protection — finger-safe from the front — but the terminal area is IP00, so it needs to be inside a panel or enclosure to keep fingers and tools out. Operating temperature range is -25 to +60 °C; storage range is -55 to +80 °C, which covers most plant-floor conditions.