The 3RT1035-3BW40 is a Siemens SIRIUS power contactor in size S2, rated for 22 kW at 500 V AC-3 duty — that's the motor-switching rating that governs the real load, not the higher AC-1 resistive figure. AC-3 at 400 V is 18.5 kW, and AC-4 at 400 V is 35 A, so the contactor is sized for standard three-phase induction motors up to that power band. Side-by-side mounting is permitted, which matters when packing multiple contactors in a row — no derating gap required for that layout. The front face carries IP20, the terminals are IP00, so the panel enclosure provides the environmental seal.
Solid conductors: 2x (0.25 to 2.5 mm²). Stranded: 2x (0.75 to 25 mm²). At 40 °C, the minimum permissible conductor cross-section is 16 mm² — that's the thermal derating floor, not the mechanical minimum.
Switching frequency and coil data
Maximum switching rates: AC-1 at 1200 operations per hour, AC-3 at 1000, AC-2 at 600, AC-4 at 300. Coil rated value is 48 V; at 24 V the contactor switches 10 A, at 60 V it switches 2 A, at 110 V it switches 1 A, at 220 V it switches 0.3 A, at 230 V it switches 6 A, at 400 V it switches 3 A.