What it is and what it does
The Siemens SENTRON 5SL6120-7CC is a 1-pole miniature circuit breaker rated 20 A with a C tripping characteristic. It breaks fault currents up to 6 kA per EN 60898 at 230/400 V AC — the standard for residential and light commercial distribution boards. The C-curve (5–10× In) handles moderate inrush from small motors, pumps, and lighting ballasts without nuisance trips, while still clearing hard faults fast enough to protect downstream wiring.
Fit and panel integration
Single modular width (18 mm) snaps onto standard DIN rail. Depth of 76 mm and height of 90 mm keep it within the envelope of a typical consumer unit or sub-distribution board. Mounting position is unrestricted — install vertically, horizontally, or flat. The IP20 rating (with conductors connected) is standard for enclosed panels; no special sealing required.
Environmental and compliance notes
Halogen-free and silicon-free construction — relevant for panels in clean-room or high-reliability environments where outgassing must be minimized. Rated for ambient temperatures from -40 °C to 75 °C, covering most indoor and sheltered outdoor installations. Overvoltage category III and pollution degree 2 suit fixed-installation mains distribution.