As the terminal of smart grid, smart meter has gradually entered our life. According to statistics, the installation of about 258 million smart meters has been completed in China, and there are still about 70 million new and reformed demands per year. The 20 30 40 50 60 amp auto reset circuit breaker the electric energy meter is the key device to realize the intelligent cost control function with the intelligent electric energy meter. The intelligent electric energy meter with a relatively large rated current (>60A) usually uses external circuit breaker to achieve various cost control functions.

The present situation of the external miniature circuit breaker of the electric energy meter

At present, the cost control functions used in China with the prepaid meter are divided into two categories: semi automatic and fully automatic.

The first one is semi-automatic, which is a miniature circuit breaker or relay with split tripping function. The product is composed of a common miniature circuit breakers, which is an electromagnetic device that can release the miniature circuit breaker or an independent relay. When the arrears are paid, the smart meter sends signals to make the coil of the electromagnetic device energized, control the micro circuit breaker tripping or make the relay work, so as to achieve the function of automatic arrears. But this product can only automatically achieve power failures after arrears. After paying, it is also necessary for professionals to manually switch on. Therefore, although Power Grid Corp has invested huge labor costs to maintain, it still can not solve the problem of timeliness of continuous electricity, which greatly reduces the customer's power consumption experience. At the same time, the product still has the following defects: first, it can't meet the requirements of terminal power consumption control intelligent system; two, because the space is limited after adding electromagnetic device in the mini circuit breaker, resulting in the N phase of the miniature circuit breaker does not have abnormal breaking protection.

The second is fully automatic, and it can be implemented by two kinds of devices.

One is relay type automatic reclosing, the main body is relay + electronic circuit board, and because relay has no interrupting and breaking ability, it can't realize short circuit protection. When it passes through a large current, it will easily lead to contact melting and welding, which will affect the safety of power supply system.

The second kind is the automatic reclosing of the electric attachments, the main body is the mini circuit breaker + electric attachment (the split type design, the linkage outside the handle). It has the defects of large volume, poor closing synchronization and poor reliability. The conventional reclosing miniature circuit breaker on the market, only the closing module is 27-54mm. Because of the large volume, it restricts the upgrading and transformation of the large quantity surface and wide stock table. If the table box re design, so the national grid electric energy meter terminal cost control area will cost huge wealth.