The Siemens SENTRON 5SY7503-7 is a 2-pole miniature circuit breaker (1P+N design) rated at 3 A with a C tripping characteristic. It provides a breaking capacity of 15 kA per EN 60898 and 40 kA per IEC 60947-2, making it suitable for branch-circuit protection in industrial control panels where moderate inrush currents from motor starters or contactor coils are expected.
The 3 A rating at 35 °C is the baseline; at 40 °C it derates to 2.82 A, at 50 °C to 2.62 A, and at 60 °C to 2.41 A (–). For a panel that runs warm — say 50 °C inside the enclosure — the breaker will carry 2.62 A continuously without nuisance tripping. The C-curve means the magnetic trip threshold is 5 to 10 times the rated current, so it holds through the inrush of a small contactor or a 3 A transformer primary but clears a hard short quickly. Breaking capacity: 15 kA per EN 60898 covers the domestic / light commercial fault level; 40 kA per IEC 60947-2 is the industrial rating, which means this breaker can be used downstream of a transformer with a high prospective short-circuit current without needing a current-limiting fuse upstream. The DC breaking capacity per IEC 60947-2 is 15 kA, relevant if the breaker is used in a DC distribution circuit. The 36 mm width occupies 2 modular units on a DIN rail. IP20 with connected conductors — finger-safe terminals but not washdown-rated; keep it inside a sealed panel.
Deployment context
Halogen-free and silicon-free construction is specified for environments where outgassing could contaminate contacts or optics.