The ABB S203-C10 is a 3-pole miniature circuit breaker rated 10 A with a Trip Curve C characteristic, meaning 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 short-circuit protection without nuisance tripping on startup.
Snaps onto standard DIN rail, which means it lands in any enclosure with a 35 mm top-hat profile — no adapter plates, no special backplate. Three poles in a single module saves rail space compared to ganging three single-pole breakers; you wire the incoming three-phase feed across the top terminals and the downstream loads off the bottom.