The Siemens SENTRON 5SL4108-6 is a 1-pole miniature circuit breaker with a B tripping characteristic, rated 8 A at 30 °C and 400 V AC, with a 10 kA breaking capacity per EN 60898 and IEC 60947-2. It snaps onto a standard DIN rail in one modular width (18 mm) and needs 70 mm installation depth behind the panel — the 76 mm overall depth includes the handle and terminals. Mounting position is any, so it fits tight enclosures or horizontal busways without derating for orientation.
Thermal derating and ambient limits
The 8 A rating holds at 30 °C ambient. At 40 °C it derates to 7.39 A, at 45 °C to 7.04 A, and at 55 °C to 6.37 A. If the panel runs hot — near a drive or transformer — size the breaker for the actual load at the expected ambient, not the 30 °C nameplate. The breaker itself is rated for -40 to 75 °C storage and operation, so it handles cold warehouses or rooftop enclosures.
Breaking capacity and coordination
Rated 10 kA per both EN 60898 and IEC 60947-2 at 400 V AC. That covers most residential and light commercial service entrances in Europe; for industrial panels with higher available fault current, you'd step to a higher-capacity SENTRON series. The B-curve trips at 3-5× In, so it's a good fit for resistive and lighting loads — not for motor starting, where a C or D curve would avoid nuisance trips.
Physical fit and accessories
Width is 18 mm — one modular unit — so it occupies a single slot on the DIN rail. The breaker accepts supplementary devices (shunt trip, auxiliary contacts, alarm switch) on the side, per the product extension feature. Sealable terminals (yes) let the panel builder lock the cover after commissioning. Rated IP20 with conductors connected, pollution degree 2, overvoltage category III — standard for enclosed distribution boards.
Lifecycle and sourcing
Current production — no phase-out or last-time-buy notice on record. The 5SL4108-6 is an active catalog item in the SENTRON family. Sourced and quoted to order against an RFQ through independent distribution; availability and current pricing confirmed at quote time.