The S201MUC-C6 is a 1-pole miniature circuit breaker from ABB's S200MUC series, rated 6 A with a Trip Curve C characteristic. The 6 A rating means it carries continuous loads up to that current without tripping; the C-curve (5–10× In magnetic trip) suits it for moderate inrush loads like small motors, transformers, or lighting banks where you need short-circuit protection without nuisance trips on startup. On the AC side it's rated 277 VAC with a 6 kA interrupting capacity — enough for most commercial lighting and branch circuits in North American 277/480 V panels. The DC side is rated 250 VDC with a 10 kA interrupt rating, which covers many DC auxiliary circuits and control power supplies.
The 1-pole width (roughly 17.5 mm per pole) means it occupies one module position in a distribution board. Terminal design accepts copper conductors typical for branch circuits — no special lug kit required. The S200MUC series shares the same footprint as other S200-family breakers, so a panel laid out for S201MUC-K2 will accept the C6 without rewiring the busbar or rearranging the rail.