Siemens 5SL4113-8 — 1-pole D-curve MCB, 13 A, 10 kA
The Siemens 5SL4113-8 is a 1-pole miniature circuit breaker from the SENTRON series, with a D tripping characteristic, rated 13 A at 400 V AC. Its 10 kA breaking capacity per EN 60898 and IEC 60947-2 means it can safely interrupt fault currents up to that level without upstream damage — a figure that governs coordination in a distribution panel. The D-curve (tripping between 10× and 20× In) is sized for loads with high inrush, such as motor starters, transformers, or discharge lighting — not for general-purpose resistive or lighting circuits where a B or C curve would trip faster on a modest overload. At 13 A, this breaker covers a 3 kW motor on 400 V three-phase (per the 0.8× derating rule for continuous motor load).
Thermal derating and ambient conditions
The 5SL4113-8 is rated 13 A at 30 °C, but the thermal trip element derates with ambient temperature: 12.01 A at 40 °C, 11.44 A at 45 °C, and 10.35 A at 55 °C. If the panel ambient runs above 30 °C, the effective continuous current is lower than the label rating — a common miss during summer commissioning. The breaker is rated for ambient up to 75 °C and down to -40 °C, with 95% humidity at 55 °C.
Mounting and integration
Snap-on DIN-rail mount, 1 MW (18 mm width), any mounting position. Depth is 76 mm (70 mm installation depth behind the panel). IP20 with conductors connected — standard for enclosed distribution boards. Touch protection is built in. The housing is halogen-free and silicon-free, which matters for panels in clean-room or corrosive environments.