With the rapid development of new and high technology, especially electronic information technology, the electricity consumption of industry, agriculture and commerce has increased, and the development of electric energy meters has also got faster and faster. Currently on the market meter type, model, full-featured, numerous manufacturers, quality levels are not the same, the choice is not good, not only can not play the advantages of the meter, but bring unnecessary losses. In this paper, the development and current status of single-phase watt-hour meter, the purchase of energy meter for objective reference recommendations.
1, The choice of manufacturer and brand:
Meter is a national mandatory inspection measuring instruments, according to the law of measurement, the selected meter must have a provincial Bureau of Technical Supervision issued measuring instruments manufacturing license (CMC card). This is the power meter manufacturers to be recognized by the power company conditions and must fulfill the legal formalities, it can prove that manufacturers have the basic facilities, personnel and testing equipment, is able to produce products for sale.
Most of the current meter manufacturers on the market are in the workshop-style production, there is no provincial measurement permits, only the municipal measurement permit. Selection of low-quality components, the circuit board for a simple meter assembly, commissioning, the quality of the meter is not guaranteed, the service life is not long, does not meet the national meter technical specifications, not recognized by the power company. Such manufacturers are mostly in Wenzhou area meter companies.
When we use the power meter to choose the formal production of electricity meters. For example: Changsha Weisheng, Shenzhen Branch Lu, Ningbo Samsung, Hangzhou Huali, Jiangsu Lin Yang and other manufacturers, with provincial measurement permits, more than two thousand domestic manufacturers in the meter win, and has the Hong Kong Stock Exchange The SSE, Shenzhen Stock Exchange and other markets, product models complete, quality assurance.
In the choice of meter brands, it is recommended to ask the staff to pay the power company, or look at the power company to you what is installed on the meter, which meter brands to choose.
2, The choice of meter specifications:
The common voltage specification of single-phase watt-hour meter is 220V, the current specifications are 1.5 (6) A, 5 (20) A, 5 (60) A, 15 (60) A, 20 (80) A and so on.
Many specifications of the meter, the general voltage specifications are 220V, the current specification of choice is mainly the user's load, the upper limit of the general load current meter can not exceed the rated current, lower limit not less than the allowable error within the watt-hour meter specified load current. For example: the user's power consumption is about 10KW, voltage is 220V, the current is 10000 ÷ 220 ≈ 46A, that is, the use of power in addition to 220, the current value is about 46A, taking into account to reserve a certain margin, you can Use 5 (60), 15 (60) A current specifications. You can also choose a smaller current size, then connect the current transformer on the line.
3, Meter current transformer selection:
Current transformer can convert a larger value of a current through a certain ratio to a smaller value of the secondary current, used for protection, measurement and other purposes. For example, a 100/5 current transformer can convert a current of 100 A into a current of 5 A.
Current transformer specifications, mainly for low-voltage users, low-voltage users because of electricity load may be free to change, poor electricity consumption estimates, so the transformer specifications are not fixed, generally based on the known power to calculate, For example, the user with electric power 100KW, the voltage is 220V, the current should be about equal to 100000 ÷ 220 ≈ 455A, that is to say, the electric power is divided by 220, the current value is obtained, just calculated is about equal to 455A, but considering To reserve a certain margin, you need to select the current transformer 500A, transformer secondary output current is generally 5A, so the choice of 500 to 5 of the transformer, the accuracy of the current transformer needs to be at least in the same meter A grade.
4, Benefits of good meter choice:
We all know that the biggest function of watt-hour meter is to measure the power, but the meter measurement is not accurate, we do not know. In fact, inaccurate meter metering inaccurate with the meter in the production of calibration errors related to the state metrological verification rules 596 which have provisions, how many levels of the meter error range. For example, in the national accreditation procedure JJG596-1999, the error range of the 100% 1.0 point of the 0.5S energy meter connected to the transformer is ± 0.5%, 1.0 is the power and 100% is the current, that is, the low current 0.5S meter in the case of normal current measurement of electricity will have a deviation of 0.005, if the use of 1000kwh electricity, electricity meter may be measured 1000 ± 5 degrees. Formal manufacturers in the meter calibration error control more stringent than the national standard, only the regular manufacturers can control the error of the meter.
Meters will produce a certain amount of electricity consumption electricity, and some meter metering sensitivity can be measured to some meter measurement sensitivity in general, can not be measured. So, if the customer bought the meter for own use, for payment, you can choose to measure the average sensitivity of the meter, such as RADARKING's DDS155 and DDSY150 and other single-phase electronic meter; if the customer is to buy electricity meter for electricity , You can choose to measure the high sensitivity of the meter,
Select the right meter will bring some benefits to customers, but it must be regular meter manufacturers, because the general production of the meter can not control the meter error, does not meet the national measurement requirements, not recognized by the power company.
5, Pay attention to the purchase meter:
Although the mill-type meter is not approved by power companies, it is still circulating in the current market, especially in the market where the very low price meter can not be used, but tens of dollars of single-phase meters and components The price is about the same, do not say manpower, material resources, such meter quality in the end how, we can imagine. There are a lot of people think it is cheaper to buy, but it will take a while before they change again. There is nothing wrong with the quality, the measurement is not accurate, and the loss will be even greater. Therefore, it is recommended that you buy the regular meter.