The Siemens SENTRON 5SL4440-8CC is a 4-pole miniature circuit breaker (MCB) from the 5SL series, rated 40 A with a D tripping characteristic. It breaks fault currents up to 10 kA per EN 60898 at 400 V AC, which means it handles high-inrush loads like motor starters and transformers without nuisance tripping — the D curve allows a short magnetic trip delay for those startup surges. Rated frequency is 50 Hz, and it carries a maximum 440 V AC in multi-phase operation.
Panel fit and wiring
Mounts on standard DIN rail in any position — no derating for orientation. It occupies 4 width units (72 mm wide, 90 mm high, 76 mm deep) with a 70 mm installation depth behind the panel. Terminals accept solid or stranded copper from 0.75 mm² up to 25 mm², torqued to 2.5–3 N·m. The housing is IP20 with connected conductors, sealable, halogen-free, and silicon-free — fine for residential and infrastructure panels where off-gassing matters.