SIRIUS S2 contactor, 3-pole, AC coil
The Siemens 3RT7035-1AC20 is a Size S2 contactor from the SIRIUS family, with three main poles and three normally-open main contacts. The magnet coil draws 0.73 W to close and holds at 0.41 W DC.
Main current circuit and auxiliary/control circuit both use screw-type terminals. Wire capacity is 2x (0.5 to 1.5 mm²) or 2x (0.75 to 2.5 mm²) solid/stranded, and finely stranded with ferrule. Side-by-side mounting is allowed, so multiple contactors can pack tightly on the rail. Pollution degree 3 applies, so it's rated for conductive environments typical of industrial panels. Auxiliary switch blocks can be added (product extension auxiliary switch: Yes).
For short-circuit protection, Type 2 coordination requires a gL/gG NH 3NA fuse rated 80 A; Type 1 coordination allows a 125 A fuse of the same type. This matters when coordinating with upstream breakers for selectivity. The contactor handles mechanical shock: 15g for 5 ms and 8g for 10 ms sine pulse. Operating temperature range is -10 to +55 °C; storage from -25 to +70 °C. Maximum switching frequency is 800 operations per hour under AC-3 duty, and 250 per hour under AC-4 (plugging/inching). That's typical for a contactor this size — fine for normal motor starting, but limit if you're doing frequent reversing.