The Siemens 5SL3108-7 is a SENTRON 5SL3 miniature circuit breaker (MCB) — a 1-pole, C-curve device rated 8 A at 400 V AC, with a 4.5 kA breaking capacity certified to both EN 60898 and IEC 60947-2. It's built for residential and infrastructure panels — think lighting circuits, general-purpose socket outlets, small HVAC loads in a distribution board.
Rated 8 A at 400 V AC single-phase, with a maximum of 250 V AC for single-phase operation and 440 V AC for multi-phase setups. If you're specifying to IEC 60947-2 for industrial control panels, the same 4.5 kA figure applies, so it's consistent across both standards. The C-curve tripping characteristic (5–10× In) is the most common choice for general-purpose circuits. It's a step above B-curve (3–5× In) which is too sensitive for motor starts, and below D-curve (10–20× In) which is for high-inrush loads like transformers or welders. For a lighting or socket circuit in a residential board, C-curve is the default. For a fixed installation that sees maybe a few operations a year (on/off for maintenance), that's effectively lifetime. The device is sealable, which matters for utility metering or tamper-proof installations.
Dimensions: 18 mm wide, 90 mm high, 76 mm deep. That's a standard 1-module footprint — it clips onto any 35 mm DIN rail and occupies one slot. The halogen-free and silicon-free construction is worth noting for clean-room or sensitive environments where outgassing matters. The touch protection feature (finger-safe terminals) means you can work on adjacent circuits without de-energizing the whole board, as long as you follow standard safe isolation practices.