Siemens SENTRON 5SY8432-8BB08 — 4-pole D-curve MCB, 30 kA IEC breaking capacity
The Siemens SENTRON 5SY8432-8BB08 is a 4-pole miniature circuit breaker with a D tripping characteristic, rated for 400 V AC (multi-phase) and 440 V AC single-phase operation at 50/60 Hz. Its 30 kA breaking capacity per IEC 60947-2 at 400 V AC means it can safely interrupt high fault currents in industrial distribution — the D curve provides a higher magnetic trip threshold (10–20× In), suited for loads with high inrush such as motors, transformers, or welding equipment where a B or C curve would nuisance-trip on startup. IP20 protection (with connected conductors) is standard for enclosed panel use. Vibration resistance per IEC 60068-2-6 covers ±1 mm at 5–25 Hz and 50 m/s² at 25–150 Hz, making it suitable for machinery mounted on vibrating equipment. The unit is halogen-free and silicon-free, and its sealable design supports tamper-evident locking for compliance-sensitive installations.
Lifecycle & sourcing — active production, quoted to order
The breaker accepts plug-in auxiliary devices (shunt trip, alarm switch, auxiliary contact) via the product extension interface, allowing field-configurable signaling without replacing the base unit.
Integration notes — DIN-rail fit and ambient derating
Installation depth is 70 mm, leaving clearance behind the panel for wiring. Ambient temperature range is -40 °C to +75 °C, with humidity limits: max 95% RH at 55 °C, derating to 35% RH at 75 °C.
Regulatory & compliance — approvals and documentation
Rated per IEC 60947-2 (30 kA at 400 V AC) and also carries a 5 kA rating per UL 1077 / CSA C22.2 No. 235 for North American supplementary protection applications. The DC rating is limited to 72 V maximum — not a general-purpose DC breaker for higher voltages. The product is halogen-free and silicon-free, meeting common environmental compliance requirements for industrial equipment. Documentation (datasheet, CE declaration, RoHS/REACH statements) is available on request.