63 A, Curve K — the inductive-load breaker for 277 VAC panels
The ABB S203PR-K63 is a 3-pole miniature circuit breaker from the S200PR series, rated 63 A continuous with a Trip Curve K characteristic and a 10 kA interrupting capacity at 277 VAC. Curve K means the magnetic trip threshold sits between 8× and 12× rated current — designed for inductive loads like motors, transformers, and solenoid banks where the inrush spike would nuisance-trip a B-curve but the short-circuit protection still needs to be faster than a Z-curve. The 10 kA SCCR covers most commercial and light-industrial panel fault levels at 277/480 VAC wye. Mounts on standard DIN rail, so it drops into any 35 mm rail assembly without adapters.
Sourcing and compliance
Sourced and quoted to order against an RFQ through independent distribution. Availability and current pricing confirmed at quote time. The manufacturer provides RoHS and REACH declarations with the shipment; CE marking covers the EU low-voltage directive. No UL listing is on record for this exact variant, so verify jurisdictional acceptance if your panel requires UL 489.