Earth Ground Resistance Tester

KEDWY-BType Large Ground Grid Ground Resistance Tester

I. Instrument Overview
      Currently, in power systems, the testing of large ground grid grounding resistance mainly uses the power frequency high-current three-pole method. To prevent power frequency interference generated during grid operation and improve the accuracy of measurement results, the insulation preventive test regulations stipulate that the test current for the power frequency high-current method must not be less than 30 amperes. This leads to numerous issues such as bulky test equipment, complex testing processes, high workload for test personnel, and long testing times.
       The KEDWY-B type large ground grid grounding resistance tester, capable of measuring substation ground grids (4Ω), hydro and thermal power plants, microwave stations (10Ω), and lightning rods (10Ω), is a versatile model. It employs a new variable frequency AC power supply and incorporates microcomputer processing control and signal processing measures, effectively solving interference issues during testing, simplifying the test operation process, improving the precision and accuracy of test results, and significantly reducing the labor intensity of test personnel and testing costs.
       This instrument is suitable for testing the power frequency grounding impedance, contact voltage, step voltage, and other power frequency characteristic parameters of various grounding devices, as well as soil resistivity. Using heterodyne anti-interference technology, it can accurately measure data at the power frequency of 50Hz even in strong interference environments. The test current can reach 5A, which does not cause excessively high potentials in grounding devices during testing. It also has strong anti-interference capabilities, allowing measurements to be taken without power interruption.
II. Performance Characteristics
       1. Excellent power frequency equivalence in measurement. The test current waveform is sinusoidal, with a frequency only 5Hz different from the power frequency, using 45Hz and 55Hz for measurement.
       2. Strong anti-interference capability. The instrument uses the heterodyne method for measurement, combined with modern software and hardware filtering technology, giving it high anti-interference performance and stable, reliable test data.
       3. High precision. The basic error is only 0.005Ω, making it suitable for measuring large ground grids with very low grounding impedance.
       4. Powerful functionality. It can measure current stakes, voltage stakes, grounding resistance, step voltage, and contact voltage.
       5. Simple operation. Fully Chinese menu-driven operation, directly displaying measurement results.
       6. Reduced wiring labor, no need for high-current cables.
III. Technical Specifications
       1. Impedance measurement range: 0～200Ω
       2. Resolution: 0.001Ω
       3. Measurement error: ±(reading × 2% + 0.005Ω)
       4. Anti-interference capability against 50Hz power frequency voltage: 10V
       5. Test current waveform: Sinusoidal wave
       6. Test current frequency: 45Hz, 55Hz dual frequency
       7. Maximum output current: 3A, 5A, 10A (user-selectable current)
       8. Maximum output voltage: 400V
       9. Measurement cable requirements: Current cable copper core cross-sectional area ≥1.5mm² (3-5A),   ≥3.0mm² (10A)
                                Voltage cable copper core cross-sectional area ≥1.0mm² (3-5A),   ≥2.0mm² (10A)
     10. Power supply: AC220V±10%, 50Hz
     11. Dimensions: 440mm×350mm×210mm
     12. Instrument weight: 22.5kg (main tester unit), ground stakes and accessories: 2.5kg

Note: The product is continuously updated and improved during production. The product appearance images are for reference only (subject to the actual product), and changes may be made without prior notice.