What the ratings mean for fit
The Siemens SENTRON 5SY7608-8 is a 4-pole miniature circuit breaker (3P+N) with a D tripping characteristic, rated 8 A at 35 °C. The D curve means it tolerates high inrush currents — typically 10–20× rated current before instantaneous trip — so it is sized for motor, transformer, or heavy inductive loads where a B or C curve would nuisance-trip on startup. Breaking capacity is 15 kA under EN 60898 and 30 kA under IEC 60947-2, giving headroom for high-fault industrial panels. At 400 V AC, overvoltage category III, pollution degree 3 — standard for fixed-installation distribution boards.
Temperature derating — real-world current
Rated current drops with ambient temperature: 8 A at 35 °C, 7.26 A at 45 °C, 6.99 A at 50 °C, 6.72 A at 55 °C, 6.43 A at 60 °C. If the breaker lives in a warm enclosure or next to other heat sources, size the load to the derated value at the expected ambient — not the 35 °C figure.
Mounting and integration
Snaps onto DIN rail via the quick-assembly system; 4 modular width units (72 mm wide). Mounting position any — vertical or horizontal in the panel. Installation depth 70 mm plus conductor space; overall depth 76 mm. IP20 with connected conductors — protected against finger contact but not washdown; keep inside the enclosure. Combined terminals top and bottom accept standard copper conductors. Sealable, halogen-free, silicon-free — suitable for clean-room or low-outgassing environments.
Lifecycle and sourcing
Current production — no end-of-life notice. Sourced and quoted to order against an RFQ through independent distribution.