Performance Features:
1. Good power frequency equivalence. The test current waveform is a sine wave, with a frequency differing from the power frequency by only 5Hz, using 45Hz and 55Hz for measurement.
2. Strong anti-interference capability. The instrument uses an off-frequency method for measurement, combined with modern software and hardware filtering technology, giving the instrument 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 small grounding impedance.
4. Powerful functionality. It can measure current stakes, voltage stakes, grounding resistance, step voltage, and contact voltage.
5. Simple operation. Full Chinese menu-based operation, directly displaying measurement results.
6. Low wiring labor, no need for large current cables.
Technical Specifications:
1. Measurement range: 0～150Ω (including current stake impedance)
2. Resolution: 0.001Ω
3. Measurement error: ±(reading ×2%+0.005Ω)
4. Maximum output voltage: AC 400V (45Hz, 55Hz, dual frequency, sine wave)
5. Maximum output current: AC 5A (45Hz, 55Hz, dual frequency, sine wave)
6. Current output gears: 5/4.5/4/3.5/3/2.5/2/1.5/1A, with 0.5A increments, 9 gears in total.
7. Anti-interference capability: withstands 50Hz power frequency voltage of 10V
8. Measurement line requirements: current line copper core cross-section ≥1.5mm
voltage line copper core cross-section ≥1.0mm
9. Power supply: AC 220V±10%, 50Hz
10. Dimensions: 440×350×210mm
11. Instrument weight: 30kg
The ground grid ground resistance tester is composed of a high-power variable frequency signal source, coupling transformer, high-precision multi-function frequency-selective multimeter, and other accessories.
DIDW-5A ground grid ground resistance tester, also known as ground grid ground resistance tester, large ground grid ground resistance tester, and 5A ground grid ground resistance tester, is suitable for testing the grounding resistance of large ground grids in power departments, substations, etc. It 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.
Instrument Overview:
Currently, in power systems, the testing of grounding resistance for large ground grids 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 30A. This leads to problems such as bulky test equipment, complex test procedures, high labor intensity for test personnel, and long test durations.
The large ground grid ground resistance tester can measure substation ground grids (4Ω), hydro and thermal power plants, microwave stations (10Ω), and lightning rods (10Ω). It adopts a new type of variable frequency AC power supply and uses microprocessor control and signal processing measures, effectively solving the anti-interference problem during testing, simplifying the test operation process, improving the precision and accuracy of test results, and greatly reducing the labor intensity and test cost for test personnel.
