Siemens 5SL4263-7CC — SENTRON 2-pole MCB, C-curve, 63 A
The Siemens 5SL4263-7CC is a SENTRON miniature circuit breaker rated 63 A at 30 °C with a C tripping characteristic, designed for 2-pole (2P) protection in residential and infrastructure panels. Its 10 kA breaking capacity per EN 60898 at 400 V AC means it safely interrupts fault currents up to that level without cascading upstream — a standard requirement for final distribution boards in commercial buildings. The C-curve (5–10× In magnetic trip) suits moderate inrush loads like small motors, pumps, and lighting banks where you need short-circuit protection without nuisance tripping on startup.
Thermal derating and ambient limits
The 63 A rating holds at 30 °C ambient. At 40 °C it derates to 59.67 A, at 45 °C to 57.93 A, at 50 °C to 56.14 A, and at 55 °C to 54.29 A — per the datasheet's published curve. If your panel ambient runs above 40 °C, size the branch circuit for the derated value, not the nameplate 63 A. Operating range spans -40 °C to 75 °C, so it handles outdoor enclosures in cold climates without issue.
Physical fit and mounting
Occupies 2 modular width units (36 mm wide) on a DIN rail. Depth is 76 mm; installation depth behind the panel surface is 70 mm. Mounting position is unrestricted — any orientation works. IP20 with connected conductors, so it belongs inside a closed enclosure, not exposed to washdown or dust. Pollution degree 2 and overvoltage category III are standard for fixed-installation distribution boards.