D-curve tripping for high-inrush loads
The 5SJ4305-8HG42: The D characteristic means this 5SJ4 breaker tolerates the 10–20× rated-current inrush typical of motor starters, small transformers, and solenoid banks without nuisance tripping — it's the standard choice for industrial control panels where inductive loads share the branch. Rated 10 kA per EN 60898 and 15 kA per IEC 60947-2, so it handles the higher prospective fault current in an industrial distribution board — the 15 kA figure applies when the breaker is installed per the IEC standard's industrial rules, giving you a safety margin over the 10 kA domestic rating.
DIN-rail footprint and panel fit
Three modular width units wide on a standard mounting rail — that's 54 mm on the DIN rail, with a 70 mm depth that clears most shallow enclosures when wired with combined terminals top and bottom. Mounts in any position and carries IP20 on the body with IP40 in the handle area — the toggle is shielded from accidental contact in open panels, but the terminals still need finger-safe covers if the busbar is exposed.
Sourcing and lifecycle
The 5SJ4 series is the standard industrial MCB line — not a specialty or phase-out family. For panel builders locking in a BOM, this means the part is a stable line item without imminent obsolescence risk.