What the ratings mean for fit
The S201-K6NA is a 1-pole miniature circuit breaker from the ABB S200 series, rated 6 A continuous at 277 V AC. The K trip curve tolerates moderate inrush for motor and transformer branch circuits. Mounts on standard DIN rail — snaps into any 35 mm rail in the enclosure. Single-pole format takes one module width (about 17.5 mm), so it fits tight panel layouts where you're stacking multiple branch circuits.
Compliance and approvals
Listed as a UL 1077 supplemental protector and CSA 22.2 — that means it's recognized for branch-circuit protection in industrial control panels but is not a full UL 489 branch-circuit breaker. For a panel builder, that distinction matters: UL 1077 devices can't be used as the main service disconnect, but they're standard for protecting individual loads like contactors, relays, or small motors inside a listed panel.