The Siemens 5SY4306-7KK11 is a 3-pole miniature circuit breaker from the SENTRON series, designed for AC circuits with a C tripping characteristic and a rated current of 6 A at 35 °C. The 10 kA breaking capacity per EN 60898 covers standard domestic and light commercial fault levels; the 35 kA rating per IEC 60947-2 is what matters for industrial panel coordination, where upstream fault currents can be higher.
Derating and thermal reality
At 40 °C ambient the breaker must be derated to 5.71 A, at 50 °C to 5.41 A, and at 60 °C to 5.09 A. If the panel ambient runs at 50 °C, a 6 A circuit is effectively a 5.4 A device — plan the load accordingly. The breaker is rated for any mounting position and any supply cord entry position, which simplifies panel layout. It occupies 3 modular width units (54 mm) on the DIN rail, with a depth of 76 mm and an installation depth of 70 mm. The quick assembly fastening system means it snaps onto the rail without tools.