The Siemens 3RT1035-1AP00-0KF0 is a SIRIUS power contactor in size S2, built for motor switching in industrial control panels. It mounts via screw and snap-on onto 35 mm DIN rail per DIN EN 50022, and its screw-type terminals accept solid conductors up to 4 mm² and stranded up to 25 mm² — common for panel wiring in the 18.5 kW range. Rated at 18.5 kW at 400 V AC-2 duty, it handles slip-ring motor loads and moderate inrush. At 500 V it delivers 22 kW, and at 690 V it still manages 11.4 kW — useful for 690 V line applications common in mining or marine panels. The AC-4 rating of 35 A at 400 V covers plugging and inching duty cycles.
Mounting and integration
Snap-on to 35 mm DIN rail — no tools needed for the rail, but the screw terminals need a screwdriver. Side-by-side mounting is allowed, so you can gang multiple contactors without spacing gaps. The front face carries IP20 protection; the terminal area is IP00, so keep live parts behind a panel door or cover. Pollution degree 3 means it's rated for industrial environments with conductive dust or condensation. Operating temperature range is -25 to +60 °C, storage from -55 to +80 °C. The 40 °C derating point for the main circuit is 16 mm² minimum conductor size — plan your wire gauge if the panel runs hot.