We all know that there are many types of watt-hour meters, such as mechanical kWh meter , electronic watt-hour meters, and so on. However, there are many sub-categories under these major categories. The types of watt-hour meters may be different depending on the model and function.

The type of watt-hour meter is indicated by the placement of letters and numbers, and the content is as follows: variety code + group code + program number + derivative number. Such as are commonly used household single-phase watt-hour meters: DD862-4, DDS97l, DDSY97l, etc. Generally speaking, the phase wires are divided into three types: D-single-phase; S-three-phase three-wire, and T-three-phase four-wire. There are also five categories according to use: D--multi-function; S--electronic; X--reactive; Y--prepayment; F--multiple rates.

Not only the mechanical kWh meter, but also the single phase energy meter has a lot of small classifications, but in general, it is subdivided into a three-phase four-wire system and three-phase three-wire system.