Knowledge 1: How to understand the capacity of the electric energy meter?
Answer: the capacity of energy meter is expressed by max rated current.
The main rated parameters of the electric energy meter as shown in the figure below are: 220V, 5 (60) A, which means that the rated voltage of the electric energy meter is 220 V, the basic current is 5 A, and the maximum rated current is 60 A.
If the use load exceeds the maximum rated current of the electric energy meter (line overload), the electric energy meter will heat up, high temperature, burn the components in the meter, and even cause a fire.
In this case, the large-capacity electric energy meter should be replaced in time.
Knowledge 2: How much energy meter can residents apply for installation?
Answer: The single-phase watt-hour meter used by general residents has specifications such as 5 (20) A, 5 (40) A, 5 (60) A, etc. Some villas and residences use three-phase electrical appliances and need a three-phase watt-hour meter, with specifications of 3* 5 (60), 3*5 (80), etc., can be installed according to the total electrical power of household appliances.
Knowledge 3: What should be paid attention to when increasing the capacity of electric energy meter?
Answer: When increasing the capacity of the electric energy meter, attention should be paid to whether the indoor circuit meets the design requirements. If a 10 (40) A electric energy meter is selected, a copper core wire of 6 square millimeters or more should be used. If this standard is not met, it should be replaced.
When decorating the house, consider the increase of home appliances in the future, and the cross section of the wire should be appropriately enlarged or reserved for several circuits.
Knowledge 4: How to know whether the electric energy meter is working normally?
Answer: If you are using a mechanical electric energy meter, observe from the front of the electric energy meter that the aluminum turntable in the meter should rotate when you are using electricity, and should not rotate when you are not using electricity. The accuracy of the mechanical energy meter is too low. It is recommended to replace it~ If you are using an electronic energy meter, please observe the pulse indicator on the nameplate of the meter from the front of the meter. The indicator light should be on and off flashing when you are using electricity , It should always be on or off when you do not use electricity. (Note: Not using electricity refers to when you are sure that all electrical appliances in your home have been completely disconnected from the power supply, not in the standby state).
Knowledge 5: Why is there a difference between the total and sub-meters of customers who use combined meters?
Answer: There are mainly the following reasons:
（1）The total meter and the sub-meter are read wrongly, the mantissa of the sub-meter is not counted, or the date of the total and sub-meter reading is inconsistent.
（2）There may be electricity leakage in the internal line of the master meter or there may be electricity theft among customers within the scope of the master meter.
（3）During operation, a section of wire from the total meter to the sub-meter also consumes power, and the sub-meter itself also consumes power. These are all measured by the general meter, and the sub-meter cannot measure this part (normal line loss).
（4）Unreasonable installation of the sub-meters did not cover all branch lines, causing part of the power consumption to be reflected only on the total table, which increased the difference between the total sub-meters.
Do you understand the above five electric power knowledge?
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