Things you don't know about electric energy meters

In this day and age, you may not have a watch, but you must have an electric meter at home. As a meter related to people's livelihood, the electric meter is an essential tool for electricity metering and electricity bill settlement.

Have you carefully observed your electric meter? Do you use a traditional mechanical electric meter or a smart electric meter? Do you have any doubts about electric meters? Next, let’s briefly summarize some common-sense questions about electric meters.

1. From the appearance of the watt-hour meter, what kind of watt-hour meter meets the statutory requirements?

The nameplate of the electric energy meter shall at least contain the following information: electric energy meter name, model, serial number, accuracy level, electric energy meter constant, reference frequency, reference voltage, reference current and maximum current, product standard code based on, manufacturing Factory name or trademark, date of production, unit of measurement, number of decimal places or multiples of indication value. In addition, qualified meters should also have the following marks:

(1) The nameplate of the electric energy meter should have the national metrology manufacturing license (CMC) mark and the license number;

(2) The shell of the electric energy meter should be affixed with the verification certificate of the verification institution and marked with the validity period;

2. What is the meaning of the nameplate of the electric energy meter?

On the nameplate of the electric energy meter, we can see the following nouns: single-phase, three-phase, active power, reactive power, etc. The registered model is also marked on the nameplate: such as DDS×××, the first D stands for "electric energy meter", the second D stands for "single phase", and S is the prefix of "static type (commonly known as electronic type)" in English . "×××" represents different electric meters produced by different enterprises. China adopts the voltage system of 220V, and the frequency of alternating current is 50Hz. Special attention should be paid to the marked current range: for example, 5 (20) A means that the basic current is 5A and the maximum current is 20A. The nameplate is also marked with ① or ②. ① means that the accuracy of the electric energy meter is 1%, or a level 1 meter; ② means that the accuracy of the electric energy meter is 2%, or a level 2 meter.

3. Why does the red light keep flashing when the energy meter is in use?

There will be a red indicator light on each watt-hour meter—the pulse light, and the pulse light of the watt-hour meter will flash when the electricity is being used. The "1600imp/kWh" marked on the nameplate of the electric meter is the pulse constant. The pulse constant is the number of pulses per kWh, which means that the customer consumes 1 kilowatt-hour of electric energy, and the pulse light flashes 1600 times. The flashing frequency of the pulse light varies with the size of the power load. The larger the power load, the faster the power consumption will be, and the faster the pulse light will flicker accordingly.

4. How to understand the current specification of the electric energy meter?

The capacity of the energy meter is represented by the maximum current. For example, the parameter of a certain type of energy meter is 220V, 5(20)A, which means that the rated voltage of the energy meter is 220V, the basic current is 5A, and the rated maximum current is 20A. If the load exceeds the maximum current of the energy meter, the energy meter may burn out, or even cause a fire.

5. Why should the energy meter be rotated periodically?

With the prolongation of the use time of the electric energy meter, mechanical wear or electronic components will be aged, which will often cause the measurement error to exceed the international allowable error limit. In order to ensure the measurement accuracy of the electric energy meter, it is necessary to disassemble the electric energy meter for periodic verification according to the relevant regulations of the state.

6. Do smart meters run faster than mechanical meters?

Smart meters are more sensitive than mechanical meters. They use electrical appliances of a few watts or even a few tenths of a watt. Traditional meters turn very slowly or do not turn at all, but smart meters can measure accurately. Any small current will make the meter turn.

In addition, the traditional electric meter is usually an "inductive electric meter" in which a disk rotates with the electricity consumption. The disk is supported by bearings. As time goes by, the bearings will gradually age, friction will increase, and the rotation speed will slow down. The cost paid is higher than the actual use. There is less electricity, which is not the case with smart meters. So if you change the smart meter, you will feel that the meter runs faster than before.

The energy saving promoted by smart meters is actually mainly to urge users to change their living habits of electricity consumption and optimize the way of electricity consumption. Pay attention to the details of electricity usage. For example, after turning off the TV or computer, the power switch on the screen is still on, or the computer is in standby mode... Although this kind of power consumption is very small, it will accumulate a lot of electricity bills over a long period of time.