Railway-rated MCB — D-curve, 50 A, 3+N-pole
The Siemens 5SY4650-8CC11 is a miniature circuit breaker rated 400 V with a 10 kA breaking capacity, configured 3+N-pole, D-curve, 50 A, and marked for railway applications. The 3+N-pole layout gives three protected phases plus a switched neutral, common in European sub-distribution panels.
Snap-on DIN rail mounting, standard 1-module width per pole. The 3+N-pole unit occupies four modules on the rail. When ganging multiple breakers, account for thermal derating per the manufacturer's table if ambient exceeds 40 °C or if the breakers are mounted side-by-side without spacing.