scope:

This Standard specifies the watt-hour meters for general use, namely, normal watt-hour meters, precision watt-hour meters, special precision watt-hour meters, precision watt-hour meters for summation measurement of multi circuits of the current composing system, transmitter-incorporating normal watt-hour meters, transmitter-incorporating precision watt-hour meters, transmitter-incorporating precision watt-hour meters for summation measurement of multi circuits of the current composing system, that are used in combination with instrument transformers in single-phase two-wire system, single-phase three-wire system, three-phase three-wire system and three-phase four wire system circuits (hereafter referred to as "meters").

In addition, the transmitters of watt-hour meters (for connection through instrument transformer) for centralized and automatic meter reading shall be in accordance with Annex A. For meters provided with auxiliary devices, this Standard shall be applied to the watt-hour meter units under such a condition that the auxiliary devices are attached.