The Siemens 5SL6308-8CC is a 3-pole miniature circuit breaker (MCB) rated 400 V with a 6 kA breaking capacity, D-curve trip characteristic, and 8 A current rating. It sits in the Basic Devices family, Group Code P310, Product Group 3821.
What the ratings mean for fit
The D-curve (10–20× In magnetic trip) is the key selection parameter here — it's sized for loads with high inrush, like small transformers, solenoid valves, or motor starters, where a B or C curve would nuisance-trip on startup. The 6 kA breaking capacity at 400 V means it safely interrupts fault currents up to that level in a 400/415 V three-phase panel, standard for commercial light-industrial distribution boards. The 8 A rating governs the continuous load: copper conductors sized for that ampacity, and coordination with upstream protective devices. Three-pole construction means it switches all three phases simultaneously — required for three-phase loads or where simultaneous disconnection is needed. The DIN-rail mount form factor snaps into standard 18 mm per-pole enclosure space, so this unit occupies 3 x 18 mm = 54 mm of rail width.