The ABB S803S-C20 is a 20 A, 3-pole miniature circuit breaker with a Trip Curve C characteristic, meaning it trips between 5 and 10 times rated current — the standard choice for general-purpose loads like lighting, control transformers, and moderate motor inrush where you need short-circuit protection without nuisance tripping on startup. Its 50 kA interrupting rating at 400/690 VAC means it can safely clear a fault up to 50,000 amps without welding contacts or cascading damage upstream — a high-capacity rating that suits it for main distribution panels or subfeeds where fault current is substantial. Rated for 400/690 VAC and 375 VDC, it covers three-phase 400 V line-to-line and 690 V line-to-line applications, plus DC circuits up to 375 V — the DC rating is useful for control power or battery-backed loads.
DIN rail integration and panel fit
The 3-pole body occupies three modular units (3 x 17.5 mm = 52.5 mm) of rail space — plan your enclosure fill factor accordingly, especially when grouping with other breakers or contactors in a motor control center. Thermal-magnetic trip mechanism: the thermal bimetal handles overload protection (time-delayed), while the electromechanic solenoid handles short-circuit protection (instantaneous). No auxiliary electronics to fail, no power supply needed for the trip unit itself.