Rated for a 63 A branch circuit on a 240 VAC line
The S403M-C63NP is a 3-pole miniature circuit breaker from ABB's S400 series, rated 63 A continuous at 240 VAC. The Trip Curve C characteristic means it trips between 5× and 10× rated current — the standard choice for moderate inrush loads like small motors, transformers, and lighting banks where you need to ride through the start-up spike without nuisance tripping on a sustained overload. The 10 kA interrupting rating at 240 VAC is the maximum fault current this breaker can safely clear without welding its contacts or rupturing the housing; verify the prospective short-circuit current at the panel's point of installation stays under that limit.
DIN-rail integration and panel fit
Snaps onto standard 35 mm DIN rail per EN 60715. The 3-pole body occupies three modular units (each 17.5 mm wide), so it needs roughly 52.5 mm of rail width plus clearance for the outgoing conductors. The S400 family shares the same footprint as the S200 series, so a panel originally kitted with S200 breakers can accept this unit without re-drilling the backplate.