The Siemens SENTRON 5SY4505-7 is a 2-pole (1P+N) miniature circuit breaker rated at 0.5 A with a C tripping characteristic. The C-curve means it trips at 5 to 10 times rated current (2.5 to 5 A), making it suitable for protecting circuits with moderate inrush — think control transformers, small contactor coils, or PLC power supplies where the startup surge is higher than a resistive load but not as high as a motor start. The 0.5 A rating is the continuous current at 35 °C; above that, the thermal derating table applies: at 60 °C it carries only 0.4 A, so a panel running hot needs a larger frame or a lower ambient.
The 5SY4505-7 occupies 2 modular width units (36 mm) on a DIN rail, with a depth of 76 mm and an installation depth of 70 mm. The quick-assembly fastening system snaps onto the rail without tools.