Siemens 5SY4104-7CC11 SENTRON MCB — 4 A, 1-Pole, C-Curve
It is designed for branch-circuit protection in industrial control panels, distribution boards, and railway auxiliary systems — the product designation explicitly states its suitability for railway applications. Mounting position is unrestricted, so it can be installed horizontally or vertically without derating.
The 4 A rating holds at 35 °C. Above that, the continuous current must be derated: 3.76 A at 40 °C, 3.64 A at 45 °C, 3.5 A at 50 °C, 3.37 A at 55 °C, and 3.23 A at 60 °C (–). If the panel ambient runs at 50 °C, the effective capacity drops to 3.5 A — factor that into your load calculation rather than relying on the 35 °C nameplate figure. Humidity limits are specified: max 95% up to 55 °C, then 55% up to 70 °C, and 35% up to 75 °C — relevant if the breaker sits in a washdown area or coastal installation.
Construction and Environmental Compliance
The 5SY4104-7CC11 is halogen-free and silicon-free — important for applications where outgassing from a fault could corrode nearby contacts or optics, such as in clean rooms, medical equipment, or sealed enclosures. Overvoltage category III suits fixed installations and distribution boards. The breaker is sealable — a feature for applications where tamper-evident sealing is required after commissioning.