63 A, Curve B, 2-pole — what the ratings mean for fit
The S802S-UCB63 is a 2-pole high-performance miniature circuit breaker rated 63 A with Trip Curve B, meaning it trips between 3 and 5 times rated current — designed for resistive and lighting loads where inrush is low, not for motor starts or transformer banks that would nuisance-trip on a B curve. Its 50 kA interrupting rating at 480 VAC and 250 VDC gives it a high fault-clearing capacity for industrial panel feeders where available short-circuit current is substantial — the 50 kA figure is the same on both AC and DC sides, so it handles DC bus faults without derating the interrupt rating. Mounts on a DIN rail in the standard enclosure footprint, which keeps panel layout consistent with other modular devices in the same distribution board.