What it is and where it fits
The Siemens 5SJ4150-7HG41 is a 1-pole SENTRON miniature circuit breaker from the 5SJ4 series, designed for branch-circuit protection in industrial control panels. It snaps onto a standard DIN rail (35 mm) and occupies one modular width (18 mm), so it fits tight panel layouts without crowding adjacent devices. Rated 400 V AC and 60 V DC, with a C-curve tripping characteristic — meaning it handles moderate inrush currents from motor starters or contactor coils without nuisance tripping, while still clearing short circuits fast. The breaking capacity is 10 kA per EN 60898 and 15 kA per IEC 60947-2, giving headroom for high-fault installations. Pollution degree 3 and overvoltage category 3 suit it for permanent connection in industrial environments where conductive dust or condensation is present. The housing is halogen-free and silicon-free, which matters in clean rooms or areas where outgassing can contaminate optics or contacts.
Installation and wiring notes
Sealable design allows locking the handle position to prevent unauthorized switching — useful in safety-related circuits or for lockout/tagout procedures. The IP20 rating applies with connected conductors; the handle area achieves IP40. Vibration resistance tested to 50 m/s² at 25–150 Hz and 60 m/s² at 35 Hz (4 s), so it holds up in machine-mounted enclosures on conveyors or compressors.