The design of arc-extinguishing systems, as well as electronic module boards, was improved with staggered multichip   in the arc extinguish chamber, multilayer mesh piece at the outlet spraying arc and major arc curvature structure for the  piece  causing arc. Two magnetoconductivity pieces were added in the contact system and a new type of  arcpolymeric material was used for the separated plate. Analysis was made to measures which were taken to achieve the design specification. The performance of products meets the design requirements with good market response. This product has become a new generation of mini earth leak-  age circuit breaker with high price-to-performance ratio.

Key words: earth leakage circuit breaker; miniaturization; modularization; high breaking; protection function