1. Model Designations and Their Meanings
Electricity meter models are designated by a combination of letters and numbers, comprising: Category Code + Group Code + Design Serial Number + Derivative Code.
(1) Category Code. D - Electricity meter.
(2) Group Code.
1) Phase/Line designation: D - Single-phase; T - Three-phase four-wire active energy; S - Three-phase three-wire active energy; X - Three-phase reactive energy.
2) Application designation: B - Standard; D - Multifunction; M - Pulse; S - All-electronic; Z - Maximum demand; Y - Prepayment; F - Multi-rate.
(3) Design Serial Number. Represented by Arabic numerals.
(4) Derivative Code. T - Dual-use (damp-heat and dry-heat); TH - Damp-tropical; TA - Dry-tropical; G - High-altitude; H - Marine; F - Chemical-resistant/Anti-corrosion.
Examples:
DD denotes a single-phase electricity meter (e.g., models DD862, DD701, DD95).
DS denotes a three-phase three-wire active energy meter (e.g., models DS8, DS310, DS864).
DT denotes a three-phase four-wire active energy meter (e.g., models DT862, DT864).
DX denotes a reactive energy meter (e.g., models DX8, DX9, DX310, DX862).
DZ denotes a maximum demand meter (e.g., model DZ1).
DB denotes a standard electricity meter (e.g., models DB2, DB3).
2. Nameplate
The nameplate must include the following information:
(1) Trademark.
(2) Metrology license mark (CMC).
(3) Name or symbol of the unit of measurement (e.g., "kilowatt-hour" or "kWh" for active energy meters; "kilovar-hour" or "kvarh" for reactive energy meters). For the window of a drum-type register, integer and fractional digits are distinguished by different colors, with a decimal point in between; if there are no fractional digits, each digit wheel in the window bears a multiplier (e.g., ×100, ×10, ×1). For LCD displays, a decimal point separates the integer and fractional digits.
(4) Name and model of the electricity meter.
(5) Basic current and rated maximum current. Basic current (or rated current) is the current value used to determine the meter's relevant characteristics and represents its standard operating current; it is denoted as Ib. Rated maximum current is the maximum current value at which the meter maintains the accuracy specified by manufacturing standards; it is denoted as Imax. For example, "1.5(6)A" indicates a basic current of 1.5A and a rated maximum current of 6A. If the rated maximum current is less than 150% of the basic current, only the basic current is marked. For three-phase meters, the number of phases is indicated as a multiplier at the beginning (e.g., 3×5(20)A).
(6) Reference voltage. Reference voltage is the voltage value used to determine the meter's relevant characteristics and represents its operating voltage; it is denoted as Un. For three-phase three-wire meters, it is expressed as the number of phases multiplied by the line voltage (e.g., 3×100V); for three-phase four-wire meters, it is expressed as the number of phases multiplied by the phase voltage/line voltage (e.g., 3×220/380V); for single-phase meters, it is expressed as the phase voltage (e.g., 220V).
(7) Reference frequency. Reference frequency is the frequency value used to determine the meter's relevant characteristics-specifically the power frequency-expressed in hertz (Hz).
(8) Meter constant. The meter constant represents the relationship between the recorded electrical energy and the corresponding number of revolutions or pulses. For active energy meters, it is expressed as r(imp)/kWh or kWh/r(imp); for reactive energy meters, it is expressed as r(imp)/kvarh or kvarh/r(imp). These two forms of the constant are reciprocals of each other.
(9) Accuracy class. Indicated by the accuracy class number enclosed in a circle (e.g., ①, ②); if no symbol is present, the electricity meter is considered Class 2.
(10) Symbols for the number of phases and wires.
(11) Environmental withstand capability class, categorized into four groups: P, S, A, and B.
(12) Manufacturing standard.
