JD156(DZ47) series circuit breaker is used in Helmet distribution system or motor distribution system for protection overload and short-circuits in the system. The product is neoteric in structure, light in weight, reliable and excellent in performance. It has high breaking capacity, can trip quickly, and its case and items are adopted by high fire-resistant and shockproof plastics. The product, with long life, is mainly used in AC 50/60HZ single-pole 240 or two, three four-pole 415V circuit for overload and short-circuit protection as well as for unfrequented on íºCand-off switching electric equipment and Helmet circuit in normal case.