The Siemens 3RT2645-1NP35 is a SIRIUS contactor with a screw-type magnet coil accepting AC or DC control voltage. The 80 mm width and 140 mm height give it a compact footprint for a contactor of this rating class.
The 0 A at 690 V AC means this contactor is not rated for switching at that voltage; keep it below 690 V. The coil accepts AC or DC control voltage with a rated range of 175 to 280 V AC at 50/60 Hz and an initial pickup of 0.8 times nominal. This simplifies panel wiring because you don't need separate coil types for AC or DC control circuits.
Wiring and conductor sizing
The screw-type terminals accept solid conductors: 2x (0.5 to 1.5 mm²), 2x (0.75 to 2.5 mm²), or 2x 4 mm². For stranded wire, the range is 2x (10 to 70 mm²) or 1x (10 to 70 mm²). At 40 °C ambient, a single 50 mm² conductor is allowed; at 60 °C, two 35 mm² conductors.