Rated current and thermal derating
The Siemens 5SY4363-7CC is a 3-pole miniature circuit breaker from the SENTRON series, rated 63 A at AC with a C tripping characteristic. That C-curve means it trips between 5× and 10× rated current — standard for motor-starting and moderate inrush loads in industrial control panels. Per the datasheet, the 63 A rating holds at 35 °C ambient; at 40 °C it derates to 60.04 A, at 45 °C to 58.46 A, at 50 °C to 56.89 A, and at 55 °C to 55.25 A. If your panel ambient runs above 35 °C, apply that curve to avoid nuisance tripping.
Breaking capacity and coordination
Breaking capacity is 10 kA per EN 60898 at 440 V AC, 50/60 Hz. That 10 kA figure is the prospective fault current the breaker can safely interrupt under standard test conditions. For a panel with a higher available fault current — say 18 kA at the service entrance — this breaker needs an upstream current-limiting device to keep the let-through within its rating. Overvoltage category III and pollution degree 3 suit it for fixed-installation distribution boards, not for plug-in equipment.
Mounting and integration
Snaps onto DIN rail via the quick-assembly system, occupying 3 modular width units (54 mm). Depth is 76 mm, installation depth 70 mm behind the panel face. Mounting position is any — vertical, horizontal, or flat — so it fits tight enclosures without derating for orientation. The combined terminal top and bottom accept conductors without separate busbar adapters. IP20 with connected conductors means it's protected against finger contact but not against water ingress; keep it inside a closed cabinet.