The Siemens 5SY6663-7 is a 4-pole (3P+N) SENTRON miniature circuit breaker with tripping characteristic C, designed for final-circuit protection in industrial and commercial panels. It carries a dual-standard breaking capacity — 6 kA per EN 60898 and 10 kA per IEC 60947-2 — so it suits both residential-style distribution boards and industrial switchgear where higher fault currents are expected.
What the ratings mean for the panel
Tripping characteristic C means the magnetic trip operates at 5 to 10 times rated current — the standard choice for moderate inrush loads like small motors, lighting banks, and transformer primaries. The 6 kA rating under EN 60898 covers the typical domestic/commercial fault level; the 10 kA rating under IEC 60947-2 gives you headroom for industrial distribution where the prospective short-circuit current is higher. At DC (per IEC 60947-2) it handles 15 kA at up to 72 V, which matters for control-circuit or battery-backed bus protection. The 4-pole 3P+N design switches all three phases plus the neutral — required for TN-S or TT systems where the neutral must be interrupted for full isolation. Neutral conductor switching is confirmed, so this breaker can serve as the main isolator for a three-phase sub-distribution board. Rated for 400 V AC (multi-phase) and 440 V AC max, it fits standard 230/400 V grids across Europe and Asia. The wide ambient range (-40 °C to +75 °C) means it can live in unconditioned enclosures — rooftop plant rooms, unheated warehouses, or outdoor kiosks — without derating concerns.
Panel integration and mounting
Snaps onto standard DIN rail (35 mm) via the quick-assembly system — no tools needed for mounting or removal. Occupies 4 modular width units (72 mm total width). The combined terminal at top and bottom accepts both busbar and cable, which speeds up panel wiring. Mounting position is any, so it fits horizontal or vertical busbar arrangements without restriction. IP20 with connected conductors — standard for enclosed distribution boards. Degree of pollution 3 means it's rated for conductive pollution environments (typical industrial control panels). Sealable design allows the installer to lock the toggle position for lockout/tagout compliance.