Rated 20 A operational current at AC-3/400 V, it's sized for motor feeders up to that current draw in a 50/60 Hz circuit.
The S2 frame is 55 mm wide, 140 mm tall, 149 mm deep — a standard footprint that slots into most European-style motor control centers. Clearance needs: 50 mm above and below, 30 mm at the sides, 140 mm in front, zero behind. Wire range for the screw-type box terminals: 2×(0.75…25 mm²) solid/stranded or 1×(0.75…35 mm²), with torque spec 3…4.5 N·m.
The 20 A rating at AC-3/400 V is the motor-switching current — that's the number that governs whether this breaker can handle your motor's full-load amps during starting and running. The 12 W typical power loss matters for thermal management inside a sealed enclosure — at full load, that heat has to be dissipated. Shock resistance is 25 g / 11 ms per IEC 60068-2-27, adequate for industrial panel vibration.