Integration note — 5SY8663-7
The Siemens SENTRON 5SY8663-7 is a 4-pole (3P+N) miniature circuit breaker in the C-curve characteristic, rated 25 kA at 400 V AC per IEC 60947-2. That breaking capacity covers most industrial panel secondary-fault scenarios without cascading upstream — the 25 kA figure is the interrupting rating at the service entrance, not a derated branch value.
Mounts in any position — no derating for upside-down or horizontal orientation. The quick-assembly fastening method means it snaps onto the rail without tools and releases via a screwdriver slot.
Dual-rated under IEC/EN 60947-2 (25 kA at 400 V AC) and UL 1077 / CSA C22.2 No. 235 (5 kA at 400 V AC). The UL 1077 rating is for supplementary protection, not branch-circuit primary — a common distinction that matters when the panel must pass a UL 508A SCCR calculation. Overvoltage category III, suitable for fixed-installation distribution boards.