SENTRON 5SY7110-6 — 1-pole B-curve MCB, 10 A, dual-rated breaking capacity
The Siemens 5SY7110-6 is a 1-pole miniature circuit breaker from the SENTRON family, with a B tripping characteristic and a 10 A rated current at AC. It carries a 15 kA breaking capacity per IEC/EN 60898-1 and a 30 kA rating per IEC 60947-2 / UL1077 — the higher figure applies when the breaker is used as an industrial supplementary protector, not a branch-circuit device. That dual rating gives the panel designer flexibility: the 15 kA figure covers standard residential or commercial final circuits, while the 30 kA UL1077 rating allows installation in higher-fault industrial panels where the available short-circuit current exceeds 15 kA. The B curve (3–5× In) is the standard choice for resistive and general-purpose loads where inrush is low — lighting, heaters, small control transformers — and avoids nuisance trips on moderate motor starts that a C-curve would handle, so match it to the load type, not just the ampacity.
Thermal derating and ambient limits
Rated current is 10 A at 35 °C ambient. Above that, the breaker derates linearly: 9.39 A at 40 °C, 9.07 A at 45 °C, 8.74 A at 50 °C, 8.4 A at 55 °C, and 8.04 A at 60 °C. If the panel ambient runs above 35 °C — common in sealed enclosures or near heat sources — size the circuit for the derated value, not the nameplate 10 A. The breaker is rated for ambient storage from -40 °C to 75 °C and operates across that full range, but the trip curve shifts with temperature; the derating table is the safe guide for continuous loading. Pollution degree 3 (conductive pollution or dry non-conductive that becomes conductive) and overvoltage category III apply, so it's suited for fixed installations inside industrial control panels, not just clean indoor distribution boards.
Mounting and integration
Snaps onto DIN rail via the quick-assembly system — one modular width (18 mm), 76 mm deep, 90 mm tall. Mounting position is any orientation, which simplifies layout in tight enclosures. The combined terminal (top and bottom) accepts the same conductor range; the neutral conductor is not switched (single-pole only). IP20 with connected conductors — protected against finger contact but not water ingress, so keep it inside a rated enclosure. Sealable, halogen-free, silicon-free — relevant for clean-room or corrosive-environment specs where outgassing or contamination matters.