What the ratings mean for fit
The ABB S201-K10NA is a 1-pole miniature circuit breaker from the System pro M compact S201 series, rated 10 A with a K-type trip curve. The K curve means the magnetic trip threshold is 8–12× In (80–120 A instantaneous), designed for loads with moderate inrush — think motor circuits, transformers, or solenoid valves where a B curve would nuisance-trip on startup but a D curve would delay too long for conductor protection. At 277 VAC (line-to-neutral on a 480Y/277 V system) it interrupts faults up to 6 kA, which covers most commercial panelboard applications; verify the available fault current at the installation point stays under that 6 kA rating.