Integrator's spec recap
The Siemens 5SN6320-8CN is a SENTRON 5SN6 miniature circuit breaker (MCB) with a D tripping characteristic, rated 20 A at 400 V AC across three poles. Its 6 kA breaking capacity per EN 60898 covers most commercial and light industrial panelboard applications where fault levels stay under that threshold. The D-curve (10–20× In) is the right call for loads with high inrush — motor starters, small transformers, or banks of LED drivers — where a B or C curve would nuisance-trip on the magnetizing surge.
Mounting and wiring
Occupies 3 width units (54 mm) on a DIN rail. Mounting position is unrestricted — any orientation works, which simplifies layout in tight enclosures. Installation depth is 70 mm, overall depth 76 mm. Terminals accept solid or stranded conductors from 0.75 to 25 mm²; tighten to 2.5–3 N·m. The housing is IP20 with conductors connected — standard for panelboard use, not for wet areas.