Working Conditions of the Multifunction Energy Meter

A multifunction energy meter refers to an watt-hour meter that has more than two functions of time-sharing and demand measurement in addition to measuring active (reactive) power, and can display, store and output data.

1. Working conditions of the multifunction energy meter

1.1 Standard reference voltage: 220V
1.2 Standard reference current: 5A, 10A, 15A, 20A
1.3 Maximum current: 4 times or more than the rated current, and run at 1.2Imax for 1 hour, the meter should not be damaged
1.4 Standard reference frequency: 50Hz

2. Mechanical requirements for multifunction energy meter

2.1 Watch case: There should be a case with double-sided clamp seals, and the internal parts of the watch can only be touched after the clamp seals are broken

2.2 Shell: It should be sealed and dust-proof and have a certain strength. It should be made of flame-retardant materials that can resist deformation, anti-aging and high transparency

2.3 Bottom shell: the bottom plate is connected with the bottom plate of the terminal button box, and it is non-combustible. The temperature requirement of the terminal block and the end cover: 960°C±15°C; the temperature requirement of the watch case: 650°C±10°C; the action time: 30s±1s

2.4 Liquid crystal display: LCD displays 6 digits, including 5 integers and 1 decimal. When using liquid crystal display, the minimum storage time of its non-volatile memory should be 4 months

2.5 Output device: The meter should have a test output device, which can be touched from the front and can be monitored with suitable test equipment.

2.6 Wiring diagram: The wiring diagram should be marked. The wiring method of the terminal button box of the electric energy meter is the same as that of the 86 series.

2.7 Accessories in the table: all components in the table are anti-corrosion and anti-oxidation

2.8 Nameplate: The logo should be clear, anti-ultraviolet radiation, non-fading, with barcode, barcode coding rules

3. Electrical requirements for multifunction energy meter

3.1 Power consumption: under the reference voltage, reference temperature and reference frequency, the active power and apparent power of the electric energy meter voltage line are less than 1W and 6VA; under the basic current, reference temperature and reference frequency, the electric energy meter current The apparent power of the line is less than 1VA

3.2 Voltage and voltage influence: The specified working range: 0.9Un—1.1Un, the limit working range: 0.7Un—1.3Un, 380V voltage is applied to the voltage line for 1 hour, and there is no damage. After the test, the meter should work normally

3.3 Effect of power interruption: After the test according to regulations, power interruption has no substantial impact on the meter

3.4 Effect of short-term overcurrent: It can withstand 30Imax overcurrent without damage, and the application time is half a cycle of the rated frequency. After the test, the electric energy meter should work normally, and the error change should not exceed ±1.5% (I=Ib,cosφ =1.0)

3.5 Effect of self-heating: The error change caused by self-heating should not exceed ±1.0% (I=Imax, cosφ=1.0) and ±1.5% (I=Imax, cosφ=0.5L).

3.6 Effect of temperature rise: Under normal working conditions, the insulation should not reach a temperature that will adversely affect the operation of the electric energy meter. When the ambient temperature does not exceed 40oC, the temperature rise of the shell does not exceed 25K

3.7 Insulation: Sufficient dielectric quality should be maintained under normal use conditions, and the influence of the atmosphere and different voltages under normal use conditions should be taken into account, and it should be able to withstand the pulse voltage test and AC voltage test specified in the regulations

3.8 Electromagnetic compatibility: meet the requirements of GB/T17215-1998 and DL/T614-1997

3.9 Immunity to electromagnetic disturbance: the design of the meter should ensure that it will not be damaged or substantially affected under the influence of conducted and radiated electromagnetic disturbance and electrostatic discharge.

3.10 Requirements for key components:
Chip: variation ±0.1%, linearity ±0.2%, American ADE7755
Electrolytic capacitor: 105℃, 3000 hours, leakage current <3μA, withstand voltage ≥16V, Japanese ruby
Current-limiting capacitor: polystyrene metal film, capacity ≥ 0.33μF, Phillips
Varistor: 20K nominal voltage 620V±10%, leakage current<30μA, voltage ratio≤1.15
Sampling resistance: manganese copper alloy (passivation treatment, high temperature aging)
Crystal oscillator: imported parts or joint venture production
Chip resistors: imported parts or joint venture production
Chip capacitors: imported parts or joint venture production
Zener diode: imported parts
Light-emitting diode: low power consumption, imported parts

4. Performance requirements of multifunction energy meter

4.1 Basic error: should meet level 2.0,
Acceptance error limit: Under the specified reference conditions, meet the requirements of the technical regulations, and our bureau will accept 50% of the error limit specified in the verification regulations
Error limit in operation: Under the specified reference conditions, meet the requirements of technical regulations

4.2 The error change limit caused by other influence quantities: the additional percentage error change caused by the change of the influence quantity relative to the reference conditions given in the regulations should not exceed the limit specified in the regulations

4.3 The influence of ambient temperature: the average temperature coefficient should not exceed the limit specified in the regulations

4.4 Time-sharing function: three rates, can display the time-sharing power and total power of the specified time period in different time periods, and the daily timing error is less than 0.5 seconds/day

4.5 Meter reading: meter reading can be programmed by infrared, and the communication protocol is implemented according to DL/T 645-1997

4.6 Output port: It has standard pulse output and light-emitting diode output for testing and corresponding to the electric energy value

4.7 Electric meter error guarantee period: under normal working conditions, the average service life of the electric energy meter is at least 10 years

4.8 Battery: Cylindrical battery is used, with a service life of at least 10 years