On a 277 VAC line it interrupts faults up to 6 kA; on DC circuits it handles 500 VDC and 10 kA interrupting capacity, covering most control-power and solar-combiner applications. The DIN-rail mount snaps into any standard 35 mm rail in a distribution board or sub-panel.
The 277 VAC rating covers single-phase line-to-neutral in North American 277/480 Y systems; the 500 VDC rating handles string-level PV circuits or DC bus protection. Trip Curve B avoids nuisance tripping on lighting and resistive heater loads while still clearing a hard fault fast.