The Siemens 5SJ6402-7 is a 4-pole miniature circuit breaker from the SENTRON 5SJ6 series, rated 2 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 — enough for branch-circuit protection in most commercial and light-industrial panels.
The 2 A rating and C-curve (magnetic trip between 5 and 10 times In) suit it for protecting smaller loads like control transformers, lighting circuits, or motorized valves where inrush is moderate. Four poles in a single unit (4 width units) let you switch all phases plus neutral in one DIN-rail footprint, saving rail space compared to ganging single-pole breakers.
Its 70 mm installation depth fits common enclosure depths. The terminals accept solid or stranded conductors from 0.75 to 25 mm², which covers most branch-circuit wiring sizes.