Panel fit and breaking capacity
The Siemens SENTRON 5SL4250-7 is a 2-pole miniature circuit breaker rated 50 A with a C-trip curve, designed for 400 VAC multi-phase circuits. Its 10 kA breaking capacity, certified to both EN 60898 and IEC 60947-2, means it can safely interrupt fault currents up to that level without upstream coordination issues in residential or infrastructure panels. The 36 mm width (2 modular units) snaps onto standard DIN rail; the 76 mm depth leaves clearance for wiring in a typical distribution board.
Environmental and installation notes
Rated for ambient temperatures from -40 °C to 75 °C, the 5SL4250-7 handles outdoor enclosures or unheated utility rooms without derating concerns. The housing is halogen-free and silicon-free, which matters for panels in clean-room or corrosive environments where outgassing can contaminate contacts. IP20 with connected conductors is standard for enclosed distribution boards; the sealable design allows lockout/tagout on the toggle. Mounting position is unrestricted, so it can be installed horizontally or inverted if the panel layout demands it.
Coordination and accessories
The C characteristic (tripping between 5× and 10× In) suits motor-starting and moderate inrush loads common in infrastructure circuits. The 3.6 W power loss per pole at rated current is within the typical range for a 50 A MCB; factor it into enclosure thermal calculations if multiple units are ganged. Supplementary devices (auxiliary switches, shunt trips, under-voltage releases) can be installed on the side, which simplifies selective coordination in multi-tier distribution.