Part identity and key ratings
The Siemens 5SL4263-7 is a 2-pole miniature circuit breaker from the SENTRON series, rated 63 A with a C tripping characteristic and a 10 kA breaking capacity at 400 V AC per EN 60898 and IEC 60947-2. At 40 °C ambient the continuous current derates to 59.67 A; at 55 °C it drops to 54.29 A, so a panel near a furnace wall or roof should account for the thermal headroom.
Mountable in any position, sealable for tamper-proofing, and halogen-free / silicon-free for use in environments sensitive to outgassing (clean rooms, food processing, marine).