The Siemens 5SY4440-7CC is a SENTRON 4-pole miniature circuit breaker with a C-curve tripping characteristic, rated 40 A at 35 °C and delivering a 10 kA breaking capacity per EN 60898. The quick assembly system and any-position mounting simplify panel integration — no orientation restrictions.
Thermal derating and environmental limits
The 40 A rating holds at 35 °C ambient. Above that, derate stepwise: 38.12 A at 40 °C, 37.12 A at 45 °C, 36.12 A at 50 °C, and 35.08 A at 55 °C. The breaker operates from -40 °C to 75 °C, with humidity limits of 95% up to 55 °C, 55% up to 70 °C, and 35% at 75 °C.
Construction and compliance
Halogen-free and silicon-free construction. Sealable terminals (combined top and bottom) allow tamper-proofing after commissioning. IP20 with connected conductors. Energy limitation class 3. The breaker is designated F per EN 61346-2 and IEC 81346-2. Suitability for mechanical engineering and industry is stated. Neutral conductor is not switched — the 4-pole design switches all three phases plus a non-switched neutral.