The Siemens 5SY4463-7KK11 is a SENTRON miniature circuit breaker rated 63 A at AC with a C tripping characteristic, meaning it handles moderate inrush loads like motor starters and lighting banks without nuisance trips — the magnetic release fires at 5–10× rated current. Four poles (4P) let you switch all three phases plus neutral in a single unit, saving DIN rail space over ganging single-pole breakers. Breaking capacity is 10 kA per EN 60898 and 15 kA per IEC 60947-2. Designed for railway applications per the product designation, with a wide ambient range of -40 °C to 75 °C and pollution degree 3 (conductive pollution or dry non-conductive that becomes conductive). That temperature span covers unheated switchgear cabinets in cold climates and hot transformer rooms alike.
The 63 A rating holds at 35 °C ambient. At 40 °C it derates to 59.98 A, at 50 °C to 56.83 A, and at 60 °C to 53.42 A.