A mechanical kWh meter is an electrical meter that uses electromagnetic force to make the movable part of the measuring mechanism produce mechanical actions to reflect the measured size. The amount of electricity that a mechanical meter can accept is current, voltage, or the product of two currents. Because the nature and size of the amount of electricity that can be directly accepted by the measuring organization are limited, it is often necessary to use a measuring circuit to convert the measured value into a transitional amount that the measuring organization can accept in advance.
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 our 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 rate.
Not only mechanical watt-hour meters, single phase energy meter and other watt-hour meters work like this.xsjbearing.com