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. The C-curve means the magnetic trip operates at 5 to 10 times rated current — suited for residential and infrastructure circuits where moderate inrush from small motors or fluorescent lighting is expected. 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.
Integration and mounting
Occupies 2 modular width units (36 mm) on a DIN rail, with an installation depth of 70 mm and overall depth of 76 mm — fits standard distribution boards without oversize enclosures. 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). IP20 with connected conductors — suitable for dry indoor panels; not rated for washdown or outdoor exposure without a secondary enclosure.
Electrical coordination
Rated for 400 V AC phase-to-phase (multi-phase operation up to 440 V AC) and 72 V DC maximum — the DC rating is lower than many competitors, so verify polarity and arc characteristics if used in a DC circuit. Mechanical service life is 10 000 switching cycles typical — adequate for branch-circuit protection where the breaker operates infrequently; not a switch-disconnector for frequent load making/breaking. Overvoltage category III, pollution degree 2 — suitable for fixed installations downstream of the main distribution board.