The S201P-K1 is a 1 A, 1-pole miniature circuit breaker with Trip Curve K, rated for 277 VAC and a 10 kA interrupting capacity. The Trip Curve K characteristic trips magnetically between 8 and 12 times rated current (so 8–12 A for this 1 A unit), which is designed for loads with moderate inrush like small transformers, solenoid valves, or motor starters where a standard C-curve might nuisance-trip on startup. The 1 A rating makes it a fine spare for control transformers or instrumentation circuits drawing under an amp — keep one on the shelf for that low-current feeder that always seems to fail on a Friday.
DIN rail integration
Single-pole width (roughly 17.5 mm per pole) means it takes up one module space in the enclosure. For a panel with mixed C-curve and K-curve breakers, the S201P-K1 shares the same footprint and busbar pitch as the rest of the S200 series — no adapter needed.