Motor protection circuit breaker, Size S0, Class 10
The 100 kA breaking capacity at 400 V AC (and at 240 V, 500 V, 690 V AC) means this breaker can safely interrupt fault currents up to 100 kA without welding contacts or cascading failure upstream — essential for panels with high available fault current near large transformers. Phase failure detection protects motors against single-phasing, which otherwise causes overheating and winding damage — a key requirement for three-phase motor circuits. Size S0 defines the physical footprint and terminal capacity: screw-type terminals for the main circuit accept 2x (1 to 2.5 mm²) or 2x (2.5 to 10 mm²) solid or stranded conductors, with M4 main contact screws.
Minimum clearances: 50 mm upwards and downwards, 30 mm to the side; no clearance needed forwards or backwards. Any mounting position is permitted, simplifying panel layout.