With the continuous progress of the times, people are more and more inseparable from electric energy. Whether it is electrical products or the small light at night, it is particularly warm in winter. However, any warmth comes at a price. Since we use electricity, it is inevitable to pay electricity bills. So related computer instruments came into being, namely electric energy meters. Later, various electric energy meters appeared, such as single phase energy meter .

The rated voltage of single-phase energy meters is 220 (250) V and 380V. They are used in 220V and 380V unidirectional circuits respectively.

The rated current of the electric energy meter has multiple levels. Such as 1A, 2A, 3A, 4A, 5A and so on. It indicates the maximum current that the electric energy meter can safely flow through for a long time. Sometimes, the rated current of the electric energy meter is marked with two values, the latter is written in brackets, such as 2 (4), which means that the rated current of the electric energy meter is 2A, and the maximum load can reach 4A. The domestic AC energy meters are all used in the 50HZ power grid, so their use frequency is also 50HZ.

The above is part of the small understanding of the electric energy meter. In addition to the single-phase electric energy meter, the mechanical kWh meter is also a very popular electric energy meter, and there are many users.