SIRIUS S2 Power Contactor — 3RT1035-3AG20
It is rated for 22 kW at 500 V in AC-3 duty and 18.5 kW at 400 V in AC-2 duty, making it suitable for standard induction motor starting and reversing applications. The coil is wound for 110 V at both 50 Hz and 60 Hz, with an operating voltage range of 0.8 to 1.1 times rated value at 50 Hz and 0.85 to 1.1 at 60 Hz.
The AC-3 rating of 22 kW at 500 V is the key selection number for standard squirrel-cage motor starting — that's the load it handles across the line without welding contacts. At 690 V the same contactor is rated for 11.4 kW AC-3, so it's not a universal derating curve — check the voltage column for your line. Mechanical service life is rated at 10,000,000 operations typical, with maximum switching frequencies of 1,200 cycles/hour in AC-1, 1,000 in AC-3, and 300 in AC-4. For high-duty-cycle applications like frequent jogging or plug reversing, the AC-4 limit governs — 300 cycles/hour is the ceiling before contact wear accelerates. Auxiliary contacts handle 10 A at 24 V, 6 A at 230 V, and 3 A at 400 V — sufficient for control-circuit interlocking and PLC inputs. The main circuit uses screw-type terminals accepting 2x (0.75 to 25 mm²) stranded or 2x (0.25 to 2.5 mm²) solid, with an alternative rating of 2x (0.75 to 16 mm²) for mixed wire sizes.
Side-by-side mounting is permitted — no derating required for zero-gap installation in a crowded enclosure.