Siemens SENTRON 5SL4620-8 — D-curve MCB for high-inrush loads
The Siemens SENTRON 5SL4620-8 is a 3P+N miniature circuit breaker with a D tripping characteristic, rated 20 A at 400 V AC and a 10 kA breaking capacity per EN 60898. The D-curve (10–20× In) is designed for loads with high inrush currents — motor starters, transformers, or power supplies — where a B- or C-curve would nuisance-trip on start-up. The 3P+N configuration includes a switched neutral, so it suits single-phase or three-phase circuits where neutral disconnection is required. Rated 20 A at 30 °C ambient; at 40 °C the continuous rating derates to 18.48 A, and at 55 °C to 15.92 A — factor this into panel thermal calculations if the breaker is in a warm enclosure. The 10 kA SCCR at 400 V AC means it can safely interrupt fault currents up to that level without upstream fusing, per EN 60898 and IEC 60947-2.
Panel fit and integration
Occupies 4 modular width units (72 mm wide) on a DIN rail. Depth is 76 mm, installation depth 70 mm. Mounting position is any — no derating required for horizontal or inverted orientation. IP20 with connected conductors; touch protection is built in, so no additional finger-safe covers are needed for the terminals. Sealable and halogen-free, silicon-free construction — suitable for installations with strict material-compatibility requirements (e.g., clean rooms, medical facilities). Degree of pollution 2, overvoltage category III, energy limitation class 3.