S203-K32 is a 32 A, 3-pole miniature circuit breaker from the ABB S200 series, using Trip Curve K for selective motor and transformer branch protection. Rated 480Y/277 VAC with a 6 kA interrupting capacity, it mounts on standard DIN rail for panel integration. It's a supplemental protector per UL 1077 and CSA 22.2 — meaning it backs up a branch-circuit overcurrent device rather than serving as the sole disconnect.
What the ratings mean for fit
The 32 A rating and Trip Curve K target inductive loads — motors, transformers, solenoids — where inrush current can be several times the full-load amps. Curve K trips magnetically at 8 to 12 times rated current, so it holds through motor start-up without nuisance tripping, unlike a Curve C (5 to 10x) that might drop out on a hard start. The 3-pole configuration handles three-phase circuits, common for 480Y/277 VAC motor branch feeds. The 6 kA interrupting rating at 277 VAC means it can safely clear a fault up to that level; if your available fault current exceeds 6 kA, you need upstream current-limiting fuses or a higher-rated breaker.
Compliance documentation
Listed under UL 1077 and CSA 22.2 as a supplemental protector. That means it's recognized for use within equipment (panelboards, control panels, machine disconnects) but not as a branch-circuit overcurrent device under NEC Article 240. The S200 series typically carries CE marking for IEC 60898 / 60947-2 compliance as well, though the evidence here confirms the North American approvals directly.