Siemens 5SN6325-8CN — 3-pole D-curve MCB, 25 A, 6 kA
The Siemens 5SN6325-8CN is a SENTRON miniature circuit breaker rated for 25 A at 400 V AC, with a D tripping characteristic and a 6 kA breaking capacity per EN 60898.
D-curve selectivity and real-world fit
For a 25 A breaker, that magnetic trip kicks in between 250 A and 500 A — well above the starting surge of a 7.5 kW motor or a bank of control transformers. If your panel was originally specified with a 5SL3625-7MB (C-curve, 25 A), swapping to this D-curve unit means you gain inrush headroom but lose faster trip on lower-level faults; the physical footprint (3 width units, 54 mm wide) and terminal range (0.75–25 mm² solid/stranded) are identical, so no rewiring needed.
Screw terminals accept 0.75–25 mm² solid or stranded copper; torque to 2.5–3 N·m. Rated for ambient -25 to +45 °C operating, -40 to +75 °C storage. Halogen-free and silicon-free construction.