What this contactor is
This is a Siemens SIRIUS S12 power contactor, catalog number 3RT1075-6AP36. It's a screw-fixing contactor that lives in bigger motor control centers — the kind you build when the load is serious. Coil takes 220-240 V AC, and it's rated for switching frequencies that match real motor duty: AC-3 at 500 operations an hour for regular starts, and AC-4 at 130 an hour for the plugging and reversing that eats contacts.
Mounting and wiring
It measures 160 mm wide, 214 mm high, 225 mm deep; mount vertical with up to 90° rotation and 22.5° tilt. Main power terminals accept stranded 70-240 mm²; control screw-type terminals accept solid 2x (0.5-1.5 mm²) or 2x (0.75-2.5 mm²), up to 4 mm² single.