Motor power ratings span from 2.2 kW at 220…230 V AC up to 4 kW at 480 V, 500…600 V, and 660…690 V AC, all at 50/60 Hz. The 4 kW rating at 480 V is the most common North American selection point; the 4 kW at 400 V class covers European 400 V three-phase networks.
The same contactor also carries AC-1 (resistive) and AC-4 (inching/plugging) utilisation categories, so it can handle resistive heater loads or frequent reversing duty, but the AC-3 figure is the one to match against your motor nameplate FLA. Short-time withstand ratings (Icw) are given for the power circuit: 90 A for 1 second, stepping down to 20 A for 15 minutes or longer. These numbers tell you the contactor can ride through a short-duration fault without welding its contacts — useful for coordination studies on a motor branch circuit.