For AC-4 duty (inching, jogging, plugging) the breaking current is rated 41 A at 400 V, so it can handle frequent on-load switching cycles without accelerated contact wear.
The AC-2 rating of 22 kW at 400 V is the headline number for motor duty — it tells you this contactor can switch a 22 kW slip-ring motor on 400 V three-phase supply through its full operating cycle, including breaking the current at the rated load. Maximum operating rate at AC-3 is 800 switching cycles per hour, at AC-2 it is 400 per hour, and at AC-4 it is 300 per hour — these limits are set by thermal recovery of the arc chamber, not by mechanical endurance.
Main circuit terminals accept solid conductors 2x (0.25 to 2.5 mm²) or stranded 2x (0.75 to 25 mm²), with a minimum permissible cross-section of 16 mm² at 40 °C ambient — sized for the full rated current without thermal bottleneck.