C45N series circuit breaker is used in lighting distribution system or motor distribution system for protecting overload and short-circuit in the system. The product is neoteric in structure, light in weight, reliable and excellent in performance. Its frame and parts adopt plastics of high fire-resistant and shockproof. The product, with long life, is mainly used in AC 50Hz/60Hz single-pole 240V or two, three, four-pole 415V circuit for overload and short-circuit protection as well as for unfrequent on-and-off switching electric equipment and lighting circuit in normal case.