Definition and classification of electric energy meters
Definition: An electric energy meter is an instrument used to measure electric energy consumption and consumption speed, commonly known as watt-hour meters and fire meters.
Classification: by purpose: a industrial and civil meter, b electronic standard meter, c maximum demand meter, d multiple rate meter
According to structure and working principle: a induction type (mechanical type), b static type (electronic type), c electromechanical type (hybrid type)
According to the nature of the power supply: AC meter, DC meter
According to accuracy level: Commonly used ordinary tables: 0.2S, 0.5S, 0.2, 0.5, 1.0, 2.0, etc.
Standard table: 0.01, 0.05, 0.2, 0.5, etc.
According to the installation wiring method: direct access type, indirect access type
According to electrical equipment: single-phase, three-phase three-wire, three-phase four-wire electric energy meter
Nameplate name and model
The first part: category code: D: electric energy meter
Part II: Group code: First letter S: Three-phase three-wire T: Three-phase four-wire X: Reactive B: Standard Z: Maximum demand D: Single-phase Second letter F: Multiple rate table S: Full Electronic D: Multi-function Y: Prepaid
Part 3: Design serial number: Arabic numerals
Part 4: Improve the serial number: use lowercase Hanyu Pinyin letters
Part 5: Derivative number T: Damp heat and dry heat dual use TH: For humid tropical zone G: For plateau H: For general use F: For chemical corrosion protection; K: Switch panel type J: Pulse electric energy meter with receiver
Also marked with signs ① or ②
①It represents the accuracy of the electric energy meter is 1%, or called the level 1 meter;
②It represents the accuracy of the electric energy meter is 2%, or called the level 2 meter. It is also marked with the standard code, manufacturer, trademark, and factory number used by the product.
Electric energy measurement unit
1. Active energy meter kW · h
2. Reactive power meter kvar · h
Character wheel counter window (liquid crystal display window): Integer and decimal places are in different colors, with a decimal point in the middle; each character wheel has a multiplication factor (when there is no decimal point), the LCD display of the multi-function meter has two integer and decimal places.
Accuracy level: relative error, represented by a number placed in a circle
Calibration current and rated maximum current: Calibration current (rated current): marked on the meter as the base current value of the calculated load: I b Rated maximum current: the maximum current value at which the energy meter can work normally for a long time, and the error and temperature rise fully meet the requirements ：Imax Rated voltage: Single-phase electric energy meter Marking: 220V
There are three labeling methods for three-phase meters: a. Directly connected three-phase three-wire: 3×380V b. Directly connected three-phase four-wire: 3×380/220V
Electric energy meter constant: the ratio of the relationship between the electric energy recorded by the electric energy meter and the number of turns or pulses of the turntable: r/kWh; imp/kWh Rated frequency: 50Hz