What this 8 A C-curve MCB is rated for
The Siemens 5SY3108-7 is a 1-pole SENTRON miniature circuit breaker rated 8 A with a C tripping characteristic — the standard choice for moderate inrush loads like small motors, lighting banks, and control transformers where the start-up surge sits between 5× and 10× rated current. The C-curve means it holds through that brief inrush without nuisance tripping, then clears fast on a hard fault. Breaking capacity is 4.5 kA per EN 60898 and 6 kA per IEC 60947-2. Rated voltage is 400 V AC and 72 V DC maximum. The DC rating is for control circuits.
Width is 18 mm — one standard DIN module.
Lifecycle stage is marked current — meaning Siemens has not issued a phase-out notice. This is the standard active-production 8 A C-curve 1P MCB in the 5SY3 family. No successor has been assigned because none is needed.