63 A C-curve MCB for panel and machine protection
The Siemens 5SY6663-7CC is a SENTRON miniature circuit breaker rated 63 A with a C tripping characteristic, 4-pole (3P+N) design, and a 6 kA breaking capacity per EN 60898 at 440 V AC. The 3P+N configuration switches all three phases and the neutral, with the neutral pole switching but not protected against overcurrent; that's standard for TN and TT systems where neutral overcurrent protection is handled upstream or by the phase poles.
Thermal derating and ambient conditions
Rated 63 A at 35 °C ambient, the 5SY6663-7CC derates to 60.04 A at 40 °C, 58.46 A at 45 °C, 56.89 A at 50 °C, and 55.25 A at 55 °C. If your panel internal ambient runs above 35 °C — common in crowded enclosures — size the upstream protection and load accordingly.
Mounting position any — vertical, horizontal, upside-down — no derating needed for orientation.