The ABB S201P-K16 is a 1-pole miniature circuit breaker rated 16 A with a Trip Curve K characteristic, interrupting 10 kA at 277 VAC. It is listed as a UL 1077 supplementary protector — meaning it protects downstream equipment, not the branch circuit itself. That distinction matters for panel builders: the branch-circuit overcurrent device upstream must still be sized per NEC. The DIN-rail footprint snaps into standard 18 mm per pole spacing.
Curve K and what it means on the line
Trip Curve K is the narrow band between B and C on the magnetic-trip side — typically 8 to 12 times rated current. That makes the S201P-K16 a fit for inductive loads like small transformers, solenoid valves, or motor starters where inrush is higher than a resistive load but not severe enough to need Curve Z or D. On a 16 A frame, the magnetic trip will hold through roughly 128 to 192 A peak without nuisance tripping. If your load is a motor with a locked-rotor current above that range, step up to Curve D.