MCB for DC branch protection
The ABB S282UC-K40 is a 2-pole miniature circuit breaker from the S280UC series, rated 40 A with a K tripping curve and a 500 VDC maximum voltage. It mounts on a standard DIN rail and is sized for DC branch-circuit protection in control panels, distribution boards, or industrial equipment where a K-curve characteristic is specified — typically for motor or transformer loads with moderate inrush.
Fit and deployment
The 2-pole form factor fits a standard DIN-rail enclosure. The K-curve (10–14x In magnetic trip) is selected for loads that draw a short-duration inrush — think DC motor circuits, solenoids, or transformer primaries — where a B or C curve would nuisance trip on startup. At 40 A and 500 VDC, this breaker covers moderate DC branch circuits without needing series-stringing of poles.