The Siemens SENTRON 5SJ4104-8HG41 is a 1-pole miniature circuit breaker with a D tripping characteristic, designed for high-inrush loads like motors and transformers where the starting current can exceed the nominal rating for a few cycles. The D curve means it tolerates 10–20× rated current for short durations before tripping magnetically, which keeps nuisance trips off the line while still protecting against hard faults. Rated breaking capacity is 10 kA per EN 60898 and 15 kA per IEC 60947-2 at 400 V AC, meaning it safely interrupts faults up to those levels without welding contacts or cascading upstream. For DC circuits, the maximum rated voltage is 60 V. The insulation voltage (Ui) is rated 440 V AC.
Mounting and environment
Snaps onto standard 35 mm DIN rail (EN 60715) in any mounting position. Width is one modular unit (18 mm), depth 70 mm, height 110 mm. The housing is halogen-free and silicon-free, which matters in clean-room or corrosive environments where outgassing can contaminate sensitive contacts or optics. Ambient temperature range spans -40 °C to 75 °C, covering most outdoor enclosures and unheated plant floors. IP20 with connected conductors, IP40 in the handle area — sufficient for enclosed panel installation; not rated for washdown zones. Degree of pollution 3 (conductive pollution or dry non-conductive that becomes conductive due to condensation) and overvoltage category III suit it for fixed installations downstream of the main distribution board.