Grounding Resistance Tester for Earth Network

1、 Instrument Overview

Grounding Resistance Tester for Earth NetworkAt present, in the power system, the grounding resistance of the earth grid is mainly measured using the power frequency high current three pole method. In order to prevent power frequency interference during the operation of the power grid and ensure the accuracy of measurement results, the insulation preventive test regulations stipulate that the test current of the power frequency high current method shall not be less than 30A. As a result, many problems have arisen, such as bulky testing equipment, complex testing processes, low efficiency of testing personnel, and long testing times.

A new type of variable frequency AC power supply has been adopted, and measures such as microcomputer processing control of the grounding impedance tester and signal processing have been taken to effectively solve the anti-interference problem during the testing process, simplify the experimental operation process, improve the accuracy and precision of the test results, and reduce the labor intensity and testing cost of the testers.

The instrument is a specialized device used to measure the grounding resistance of the grounding network and the grounding conductivity between the grounding points. The instrument adopts frequency conversion anti-interference technology, which does not require high current measurement and can accurately measure 50Hz data in strong interference environments of substations. The measurement results are displayed on a large LCD screen and come with a built-in micro printer for printing and output. The instrument can simultaneously measure grounding impedance and grounding resistance, which can better reflect the actual characteristics of the grounding network

2、 Functional Features

1. The measured power frequency equivalence is good. The test current waveform is a sine wave, with a frequency difference of as little as 0.1Hz and as little as 10Hz from the power frequency. It can be used for measurement at both 50Hz and 60Hz frequencies.

2. Anti interference ability. This instrument adopts the frequency difference method for measurement, combined with modern software and hardware filtering technology, making the instrument have excellent anti-interference performance and stable and reliable test data.

3. Measurement accuracy draft. The basic error is only 0.005 Ω, which can be used to measure the earth network with very small grounding impedance.

4. Functionality. It can measure current piles, voltage piles, ground grid impedance, grounding resistance, grounding conductivity, soil resistivity, step voltage, contact voltage, potential gradient, etc.

5. Full touch LCD display screen, super comprehensive graphical operation interface, every process is very clear and understandable. Operators do not require additional professional training to use it. The entire testing process can be completed with a gentle touch.

6. Equipped with a calendar chip and large capacity memory, it can save results at any time. You can view the historical records at any time and print them out Both the current time and storage time can be displayed and printed.

7. Data management: Instrument data can be exported through a USB flash drive, and can be viewed and managed on any PC through dedicated software. Capable of generating reports and experimental reports.

8. Safe and reliable. The instrument has functions such as grounding protection, current and voltage limiting protection, and sound and light alarm to ensure the safety of testing personnel and equipment.

9. Equipped with vector testing function, capable of measuring ground impedance and ground pure resistance. Impedance angle can be measured.

10. Low wiring workload, no need for high current wires.

11. Integrated model, equipped with standard resistors and constant current source for easy on-site testing and reducing on-site wiring.

12. The instrument is easy to operate, and the measurement process is controlled by a microprocessor. As long as the correct measurement method is selected, the data measurement can be automatically completed under the control of the microprocessor.

When users need high current testing (such as 30A), this instrument can be implemented by connecting an external power supply.

3、 Technical indicators

1. Measurement range: 0-5000 Ω (including current pile impedance)

2. Resolution: 0.001m Ω

3. Measurement error: ± (reading x 2%+0.005 Ω)

4. Power frequency suppression ratio: ≥ 60dB (with a resistance to 50Hz power frequency voltage interference of 10V)

5. Test current waveform: sine wave

6. Test current frequency: Single frequency: 40-70Hz Resolution: 0.1Hz, freely set

Dual frequency: freely set from 50 ± 0.1Hz to 50 ± 10.0Hz

Set freely from 60 ± 0.1Hz to 60 ± 10.0Hz

7. Maximum output current: 5A or external power supply 30A

8. Output voltage: 400V or external power supply 400V

9. Measurement line requirement: The cross-sectional area of the copper core of the current wire should be ≥ 1.5mm2

Voltage wire copper core cross-sectional area ≥ 1.0mm2

10. Test power supply: Built in 2kW variable frequency power supply or external high-power variable frequency power supply.

11. Power supply: AC220V ± 10%, 50Hz

12. Dimensions: 500mm * 377mm * 330mm

13. Instrument weight: 20kg

Sudian ElectricMain products:

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