S2 contactor, AC-3 rated, screw terminals
The AC-3 rating at 690 V defines its motor-switching capability — it handles the inrush of a squirrel-cage induction motor up to that line voltage. The 800 1/h maximum at AC-3 means it can cycle a motor start roughly every 4.5 seconds; the AC-4 maximum of 250 1/h applies for plugging or inching duty, where the contacts break stalled-rotor current. The 6 kV rated surge voltage resistance (impulse withstand) tells you it's suitable for 400 V and 690 V industrial networks without external surge suppression. Pollution degree 3 confirms it's rated for the conductive-dust and condensation environment typical of an unsealed control panel.
Dimensions are 112 mm high, 55 mm wide, 115 mm deep — the S2 frame fits alongside other SIRIUS components on the same DIN rail. The coil draws 0.79 W on closing and holds at 0.36 W DC, so the control transformer sizing is modest. The auxiliary contact block is field-addable (product extension auxiliary switch is supported).