63 A D-curve MCB for inductive loads and railway panels
The Siemens SENTRON 5SY4263-8CC11 is a 2-pole miniature circuit breaker rated 63 A with a D tripping characteristic, designed to handle high inrush currents from motor starters, transformers, and welding equipment — common in industrial and railway auxiliary circuits. Its 10 kA breaking capacity at 400 V AC (per EN 60898) means it can safely interrupt a fault up to that level without upstream damage, provided the panel SCCR is coordinated. The D curve holds through short-duration surges (10–20× rated current) before tripping, so it won't nuisance-trip on a motor start.
Terminal accepts solid or stranded copper from 0.75 to 35 mm²; tightening torque 2.5 to 3.5 N·m.
Rated for ambient temperatures from -40 to +70 °C, storage from -40 to +75 °C. Halogen-free and silicon-free construction. Overvoltage category III, touch protection integrated. Designed for railway applications per the product designation, with humidity tolerance up to 95% at 55 °C.