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. The C-curve (5–10× In magnetic trip) suits mixed inductive and resistive loads common in mechanical engineering and industry, not just lighting or motor-only branches.
Panel fit and mounting
Occupies 4 modular width units (72 mm) on a DIN rail, with a depth of 76 mm and an installation depth of 70 mm. 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. IP20 with connected conductors; pollution degree 3 covers the typical industrial panel environment where conductive dust or condensation may occur.
Standards and approvals
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.