The Siemens SENTRON 5SJ6408-7 is a 4-pole miniature circuit breaker from the 5SJ6 series, rated 8 A with a C tripping characteristic. It breaks fault currents up to 6 kA per EN 60898 and IEC 60947-2 at 400 V AC, which covers the standard panelboard fault-current requirement for most commercial and light-industrial distribution boards.
Mounts in any position on a standard DIN rail; installation depth is 70 mm, and it occupies 4 width units (roughly 72 mm of rail space). The terminals accept solid or stranded conductors from 0.75 mm² up to 25 mm² — enough for the incoming feed and through-wiring of downstream loads.
Rated insulation voltage is 440 V AC, and multi-phase operation is also rated to 440 V AC maximum. The mechanical service life is 20 000 switching cycles typical, which aligns with standard panelboard duty for branch-circuit protection. Ambient temperature range is -20 to +45 °C, with storage from -40 to +75 °C.