The Siemens 5SL4463-8 is a SENTRON miniature circuit breaker — 4-pole, D-curve, 63 A, with a 10 kA breaking capacity at 400 V AC per EN 60898 and IEC 60947-2. That D-curve means it's built for high-inrush loads: motors, transformers, welding gear — anything where the start-up spike would nuisance-trip a B or C curve. The 10 kA SCCR at 400 V is the same under both standards, so it coordinates cleanly in a residential or light commercial distribution board without needing an upstream current-limiting fuse for most fault scenarios. Rated 63 A at 30 °C, it derates to 59.67 A at 40 °C and 54.29 A at 55 °C — the thermal curve is baked into the bimetal, so if your panel ambient runs hot, size the upstream protection for the derated value, not the nameplate. The 4-pole design switches all phases plus neutral (no switched neutral component, but the neutral pole is a solid bar on this variant — check the order code if you need a switched neutral).
Thermal derating and panel integration
Mounts in any position on standard DIN rail. At 4 modular width units (72 mm wide, 90 mm tall, 76 mm deep plus 70 mm installation depth behind the panel face), it fits a standard distribution board slot. The IP20 rating with connected conductors means it's protected against finger contact but not washdown — keep it inside a closed enclosure. Sealable per the spec, so a panel builder can lock the toggle position after commissioning.