Smart meters as smart grid terminals have gradually come into our lives. According to statistics, China has completed the installation of about 258 million smart meters. There are about 70 million more needs each year. Instrument external miniature circuit breakers to achieve intelligent charging smart meter charging control of the key components. The ampere meter with larger rated current (> 60A) generally adopts the external circuit breaker to realize various expense control functions.

1. Current situation of external miniature circuit breakers in watt-hour meter.

Currently, the charge control function used in the domestic prepaid meter is divided into two categories: semi-automatic and fully automatic:

The first is a semi-automatic, it is a shunt trip with miniature circuit breakers or relays, this product is an ordinary micro-circuit breaker with a micro-circuit breaker can be added to the release of electromagnetic devices or independent relay. Arrears when the smart meter to send signals to the electromagnetic device coil control micro-circuit breaker tripping or relay action to achieve arrears automatic power-off function. However, this product can only be automatically de-energized after the arrears, and the professionals need to manually close the door after paying the fee. Although the power grid company has invested a huge manpower cost to maintain it, it still can not solve the timely problem of renewing the electricity. Greatly reduce the customer's electricity experience. At the same time the product also has the following shortcomings, one can not meet the requirements of the end of the charge-by-wire intelligent system; the second is due to the micro-circuit breaker installed in the electromagnetic device after the limited space, resulting in micro-circuit breaker N phase does not have abnormal Break protection.

The second is fully automatic, which in turn can be implemented by two devices:
One is the use of relay-type automatic reclosing, the main relay + electronic circuit board; and because the relay does not have the arc-breaking and breaking capacity, short-circuit protection can not be achieved, when it passes through a large current prone to contact welding, affecting the power supply System safety.
The second is assembled aerobics accessories automatic reclosing, the main body is miniature circuit breaker + electric accessories (split design, the handle outside the linkage). There is a bulky, sub-closing synchronization poor, poor reliability defects. The market general reclosing miniature circuit breakers, only the closing module on the 27-54mm, due to the large size, restricting the large amount of Oversea large scale meter box upgrade. If the re-design of the meter box, then the national power grid terminal meter fee control field will spend huge sums of money.

2. The new technology of external miniature circuit breaker of watt-hour meter

With the advancing of the construction of smart grid, the energy meter charge control system, as the basis of a large amount, is valued by the State Grid Corporation of China and South China Power Grid Corporation. In order to further improve the reliability of the power meter fee control system and ensure the safe and stable operation of the intelligent management and intelligent service of the power system, State Grid Corporation and China Southern Power Grid Company formulated the Technical Specifications for External Watt-hour Meter. In the future, the electric appliance specially developed FAR6-W external miniature circuit breaker (hereinafter referred to as FAR6-W) according to this standard.
The basic functions of FAR6-W are as follows: Reliable realization of arrearage automatic sub-gate power-off and payment auto-switch on and off, and precise feedback of closing, opening and fault status signals at the same time.
FAR6-W modular design, the structure is the drive module plus miniature circuit breakers. Drive module only 18mm width, single-phase plus N total width of 54mm, three-phase plus N total width of 90mm. In the industry the first breakthrough unipolar 18mm wide, the maximum rated current of 100A. Small size ensures that the FAR6-W can be easily installed in the existing standard measurement box.
The FAR6-W adopts the inner shaft transmission design, which ensures the synchronization, consistency and reliability of circuit breaker opening and closing. Drive module with manual (semi-automatic) and automatic selection function, which can effectively prevent the man-made closing power theft (that is, forcibly closed, the contact is not closed).
FAR6-W -25-60 ℃ for the temperature range, the extreme environment up to -40 ~ 70 ℃. So regardless of the summer heat in the South, or the cold winter in the North, FAR6-W can work reliably, but also to the table box installation location has brought more choices, either installed indoors, can also be installed in the ambient temperature difference Larger outdoor.
FAR6-W watt-hour meter external circuit breaker in line with "GB10963.1 home and similar places overcurrent protection circuit breaker" standard, in line with the State Grid and the Southern Power Grid "Watt-hour meter external circuit breaker technical specifications," in line with China CQC Quality Certification Center " Meter External Circuit Breaker Specifications. "