YBKN series circuit beaker is used in lighting distribution system or motor distribution system for protecting overload and short-circuit in the system. The product is novel in structure, light in weight, reliable and excellent in performance. It has high breaking capacity, can trip quickly and it's installation uses with guide. It's case and body are adopted with high fire-registrant and shockproof plastics. The product, with long life, is mainly used in AC 500Hz/60Hz single-pole 240V or two, three, four pole 415V circuit for overload and short-circuit production as well as for unfrequented on-and-off switching electric equipmented lighting in normal case. This product conform to GB 10963, IEC60898, BS3871.