The Siemens 5SJ6450-7 is a SENTRON 5SJ6 miniature circuit breaker rated 50 A at 400 V AC with a C tripping characteristic and a 6 kA breaking capacity certified to both EN 60898 and IEC 60947-2. The C-curve means it tolerates inrush currents 5–10× the rated current before tripping magnetically — sized for motor and transformer branch circuits where the start-up surge exceeds the thermal threshold but stays within the magnetic hold range. Four poles in a single 4-module-width housing (70 mm deep) let you switch three phases plus neutral in one DIN-rail footprint, saving a row of terminal blocks and a separate neutral link.
Four modular width units (each 18 mm) means it occupies 72 mm of rail space; plan your fill factor accordingly. IP20 with connected conductors is the expected finger-safe rating for an enclosed distribution board; the touch-protected terminals meet the VDE 0106 requirement for live-part guarding during panel wiring.
The 5SJ6450-7 carries a current lifecycle stage from Siemens, meaning it remains in the active catalog and is not subject to a last-time-buy or phase-out notice as of the latest manufacturer data. For BOM-freeze planning, the 5SJ6 series is a mature, widely deployed platform with consistent lead times across the range.
Halogen-free and silicon-free construction suits installations in clean rooms, data centers, or areas where outgassing from a fault event must be minimized. Vibration resistance tested to 50 m/s² at 25–150 Hz and 60 m/s² at 10–150 Hz per IEC 60068-2-6, so it holds up on machine-mounted sub-panels near rotating equipment.