Whether it is used in electrical or industrial life, there is the risk of short circuit or lightning, it is particularly important to protect the electrical appliance market. The protection is mainly divided into two types: one is the circuit breaker, fuse is two. Many types of circuit breakers, non selective and selective two categories. In addition, there are leakage protection circuit breaker protection. These appliances all have their own characteristics, nature also has its shortcomings, according to the specific conditions of their respective distribution systems and requirements, sometimes can not be easy for them. In some countries, the development of circuit breaker products and technology is very rapid, continuous development a new, better protection function products. Almost every ten years or so a replacement, until the introduction of functions, the intelligent circuit breaker with communication module, to provide protection for distribution line The excellent performance of electrical protection. China, in the recent twenty years, the development of electrical industry fairly quickly, the circuit breaker products follow the international advanced technology development trend, a variety of intelligent products, provide a better protection function for distribution lines. However, some developed countries in Europe and the United States, and not because of the rapid development the circuit breaker and the elimination of the fuse, nor the fuse as backward or outdated products. For example, some well-known electric company, not only still producing fuse, but also continue to develop new products, technology continues to progress. From these aspects: the protection of electrical circuit breaker is advanced, but also fuse no outdated or backward products. It should be said that the two complement each other, each has its own domain. There is a saying called "specialize in", may explain some special phenomenon at present.