What it is and what it does
The Siemens 5SL6115-7 is a SENTRON miniature circuit breaker (MCB) — a 1-pole, C-curve unit rated 1.6 A at 30 °C and 400 V AC, with a 6 kA breaking capacity per both EN 60898 and IEC 60947-2. That C-curve means it trips between 5 and 10 times rated current, so it's sized for moderate inrush loads like small lighting circuits or control transformers where you don't want nuisance trips from a motor start but still need fast short-circuit clearance. The 6 kA rating tells you it can safely interrupt a fault current up to that level at 400 V without welding its contacts or cascading upstream — enough for most residential and light commercial panels.
How it fits in the panel
Snaps onto a standard DIN rail — one modular unit wide at 18 mm, depth 76 mm, installation depth 70 mm. Mounts in any position, so you're not fighting orientation in a tight enclosure. Rated IP20 only with connected conductors, meaning it's for inside a panel, not out in the washdown zone. Pollution degree 2 and overvoltage category III cover normal industrial and residential environments where you get occasional transient spikes but not conductive grime.
Thermal derating you need to know
The 1.6 A rating is at 30 °C ambient. At 40 °C it derates to 1.52 A, at 45 °C to 1.47 A, and at 55 °C to 1.4 A. If your panel runs hot — say next to a drive cabinet or in a sun-baked enclosure — size up one rating step so the MCB doesn't trip on a warm day under a normal load. The mechanical service life is 10 000 switching cycles, which is typical for a residential-grade breaker; it's not a switching device for frequent motor starts.