What it is and what it does
The Siemens SENTRON 5SL3008-7 is a 1P+N miniature circuit breaker rated 8 A with a C tripping characteristic and a 4.5 kA breaking capacity per EN 60898. That C-curve means it trips between 5 and 10 times rated current — standard for general-purpose branch circuits feeding resistive and light inductive loads like lighting, socket outlets, and small appliances in residential and light commercial panels.
Fit and integration
Snaps onto standard DIN rail (35 mm), 18 mm wide (one modular unit), with any mounting position allowed. Depth is 76 mm, installation depth 70 mm. IP20 with connected conductors — fine for enclosed distribution boards. The compact design and halogen-free, silicon-free construction suit it for residential and infrastructure panels where space and material compliance matter.
Thermal derating — the real-world rating
The 8 A rating holds at 30 °C ambient. At 40 °C it derates to 7.52 A, at 50 °C to 7 A, and at 60 °C to 6.45 A. If your panel ambient runs above 30 °C, size the breaker against the derated value — not the 8 A nameplate — to avoid nuisance tripping on a warm summer day.