It's rated for 30 kW at AC-2 duty on 400 V (the standard for slip-ring motors and high-inertia starts) and can handle 55 A at AC-4 duty on 400 V, which covers plugging and inching operations where the contactor breaks full motor current.
Duty-cycle and switching life
This contactor is rated for 1,000 operations per hour at AC-1 (resistive loads) and AC-3 (standard squirrel-cage motor starting), 400 ops/h at AC-2, and 300 ops/h at AC-4. For comparison, the 3RT5044-1BM40 is the same S3 frame but with a different coil voltage or auxiliary configuration — same mounting footprint, same main current path, so it's a drop-in swap if the coil matches your control voltage.
Wiring and environmental fit
Terminal wiring: the main circuit screw terminals accept solid wire 2x (0.5 to 1.5 mm²), 2x (0.75 to 2.5 mm²), or max 2x (0.75 to 4 mm²), and stranded wire 2x (10 to 50 mm²). Auxiliary/control terminals take 2x (2.5 to 16 mm²) solid or stranded. The coil draws 10 A at 24 V, 2 A at 60 V, 1 A at 110 V, 0.3 A at 220 V, and 6 A at 230 V — watch your control transformer sizing.