The past decade, the air circuit breaker manufacturers in China have been greatly developed, the product quantity, quality, quality can basically meet the domestic demand for low-voltage power grid, and its main products are Universal and Molded Case two categories.
        At present, the production of universal-type air circuit breakers have DW15, DWX15, DW16, DW17, DW45, DW47, DW48 and other products, molded case air circuit breaker DE20, CW1, S and other products.
        China s accession to WTO, foreign products enter the domestic market, more representative of France, the United States, Germany, Switzerland, Japan and other countries, products, products in these countries represent the main technical properties of products of the highest contemporary standards of air circuit breakers.
        As can be seen from the table below, a new generation of products difficult to short-circuit breaking capacity index is already high, it can be said is much higher than the actual needs of 100 ~ 150kA short-circuit current can not be applied in practice, has become a competitive business indicators. Seen from the protection, most products have been intelligent, protective function has a perfect system, can meet requirements. Large breakers can be advanced with a communication interface products, supports a variety of field bus. The past two years on the Hanover Fair in Germany reflected the situation is much the same, more unique products is the Schneider NT16N1 products, their rated current 1600A, dimensions are the same as published on the international circuit breaker current rating the smallest in the shell frame, but only a short-circuit breaking capacity 42KA (400V). SentronWL Siemens Circuit Breaker is characterized by full series has three frame degree, each into a whole separate structure (not assembled by phase pole), thereby reducing the high current (6300A) in the form of class size and improve reliability of the product.

Circuit breaker from the perspective of the development of foreign, domestic enterprises should have the following reference points:
        An improved circuit breaker Ics, and strive to Icu = Ics. Users generally accepted Ics, the selection of circuit breakers do not accept Icu. From the manufacturer point of view, Icu and Ics two equal, simplify testing, reduce the number of test items. This large number of circuit breaker manufacturers of the actual situation is more economic sense. For Icu = Ics, should increase the Ics value. This requires from two aspects: First, improve the interrupter system, reduce the contact burns. Second, the development of pit wear contact materials, contact materials required to withstand short-circuit breaking capacity of three large contact resistance stability after the test.

        2 reduced dimensions. Dimension reduction is to increase the product s economic indicators, whether Universal or MCCB should be the case. Now narrow the large capacity (6300A) circuit breaker width is important, the use of independent structure of the Frame size (not by phase pole assembly) is an effective measure to reduce the width.

        3 MCCB 1600A the following products should be developed. From the national development situation, focus should be developed following MCCB 800A, make a good bi-metal thermal-magnetic molded case circuit breaker is essential that this product structure is simple, cheap, very welcomed by the users .

        4, circuit breaker, and large capacity (400A and above) MCCB should be the development of intelligent products, with the support of a variety of field bus communication interface to meet the requirements of modern distribution automation.