The Siemens 5SY5205-7CC11 is a SENTRON miniature circuit breaker designed specifically for DC circuits, with 2 poles, a rated voltage of 440 V DC, and a breaking capacity of 10 kA per IEC 60947-2. Its C tripping characteristic (5-10x In) makes it suitable for protecting loads with moderate inrush, such as control transformers or solenoid banks in DC distribution.
DC Ratings and Thermal Derating
Rated current at 40 °C is 0.46 A, derating to 0.38 A at 60 °C and 0.3 A at 75 °C. The ambient temperature range spans -40 °C to 75 °C, with humidity limits per the surrounding temperature influence table. For a DC bus running at 60 °C ambient, expect the continuous current capacity to drop to 0.38 A.
Panel Integration and Mounting
Occupies 2 modular width units (36 mm) on a DIN rail, with a quick assembly system and any mounting position. Installation depth is 70 mm; overall depth 76 mm. Combined top and bottom terminals accept wiring from either direction. IP20 with connected conductors — suitable for enclosed distribution boards, not for wet or washdown environments.
Railway and Environmental Qualification
Designed for railway applications per the product design designation. Vibration resistance per IEC 60068-2-6: ±1 mm at 5 to 25 Hz, 50 m/s² at 25 to 150 Hz. Halogen-free and silicon-free construction. Degree of pollution 3, overvoltage category III. Polarity must be observed on the supply cord.