Lh2a series digital display ammeter is an instrument that converts the measured voltage value into digital form by analog-to-digital converter and expresses it in digital form. It is suitable for the environment temperature of 0 ~ 50 ℃ and humidity below 85%. When the voltage is abnormal due to magnetic field or high-frequency instrument, high-voltage spark, lightning and other reasons, the external interference absorption circuit such as power line filter or nonlinear resistance should be used.

In the process of use, there are the following precautions:

1. It is suitable for environment temperature 0 ~ 50 ℃ and humidity below 85% to prevent bad phenomenon caused by temperature change.

2. Pay attention to prevent vibration and impact.

3. Do not use in places with dust, chemicals harmful to electrical products, gas, etc.

4. In case of abnormal voltage and current caused by magnetic field or high-frequency instrument, high-voltage spark, lightning and other reasons, please use interference absorption circuit such as power line filter or nonlinear resistance.

5. The input signal line should be as short as possible, and the protective shield line should be used where interference signal may be mixed. In general, twisted pair is recommended.

Lh2a series intelligent programmable digital display ammeter is mainly used for real-time measurement, monitoring and indication of single-phase, three intersecting / DC current in power station, electrical switch cabinet and various electrical equipment. It has the characteristics of high measurement accuracy, clear reading, convenience, no angle error, can be installed at any angle, anti-seismic, anti-interference of external magnetic field and so on. It is an ideal substitute for the original pointer type instrument. It can be used with all kinds of electric quantity and non electric quantity transmitters with linear analog signal output, and indicate the electric quantity or non electric quantity value in the circuit. It can be widely used in various voltage levels of urban and rural substation power plants, enterprise / institution transformation and distribution rooms and many other fields.

The instrument panel is equipped with a programmable keyboard, which can program and set the parameters of the instrument, such as the ratio of instrument transformer, upper and lower limit alarm value, alarm return difference, instrument communication address, communication baud rate, transmission output mode, transmission output range, etc. It has the characteristics of easy installation, simple wiring, convenient maintenance, small amount of work, field programmable input parameters, etc., and can complete the networking communication of PLC and industrial control computer, which is different from the industry.

The product parameters of each company's intelligent programmable digital ammeter are similar, as follows:

1. AC current measurement range: AC / dc0-5a, other specifications are used with current transformer

2. Auxiliary power supply: Standard AC220V, optional AC / DC: 80v-270v

3. Display mode: four digit LED digital tube display, sine wave average detection, effective value display

4. Accuracy: ≤ 0.5% of input full scale ± Two words

5. Overload: continuous 1.2 times, instantaneous 2 times / 1s

6. Power consumption of input circuit: < 0.5va (per phase)

7. Impedance: < 20m Ω( (per phase)

5. Auxiliary power consumption: < 5VA

8. Sampling speed: about 3 times / S

9. Frequency 45hz-65hz

10. Alarm output: the same relay output for upper and lower limit alarm, contact capacity AC250V / 2a, dc30v / 2A

11. Transmitting output: dc0-10ma, 0-20mA, 4-20mA, output load ≤ 500 Ω， Customizable voltage output

12. Communication: RS-485 communication interface, MODBUS-RTU communication protocol, baud rate 1200, 2400, 4800, 9600, 19200 can be set

13. Withstand voltage: power supply, input and output > ac2kv, 50 Hz / 1min

14. Insulation resistance > 100m Ω

 15. Heat resistant and flame retardant: Terminal: 960 ℃, shell: 650 ℃, action time: 30s

16. Electrostatic discharge ± 8kv

17. Fast transient burst: ± 1kv

18. High frequency electromagnetic field: 80mhz-1000mhz, 10V / M

19. Relay contact capacity: AC220V / 3a, service life: 1052 times

20. Working environment: temperature - 25 ~ + 55 ℃, humidity ≤ 90% RH without corrosive gas, altitude ≤ 2500m; Storage temperature: - 25-70 ℃