DCY-IIB Ground Grid Ground Resistance Tester

Estimated delivery : 30 Days; MOQ : 1 PCS
Features :
In recent years, many substations in China have suffered accidents caused by lightning strikes, most of which are related to unqualified grounding resistance of the ground grid. Therefore, it is necessary to vigorously strengthen the regular monitoring of the grounding resistance of the ground grid.
The measurement of grounding resistance of the substation ground grid in operation will produce large errors in the test results due to the interference of the system current flowing into the ground grid and the interference between the test leads. In particular, the grounding resistance of large ground grids is very small (generally below 0.5Ω), and even slight interference will have a great impact on the test results. If the grounding resistance test of the ground grid is inaccurate, it will not only damage the equipment, but also cause unnecessary losses such as wrong ground grid modification.
At present, there are many methods for testing the grounding resistance of the grounding grid, among which the main methods are the power frequency large current method and the different frequency power supply method. In order to improve the measurement accuracy, the former adopts the method of increasing the signal-to-noise ratio to reduce the influence of interference, but increasing the current makes the equipment bulky and cannot completely solve the interference problem; the latter mainly relies on changing the test current frequency (generally around 120Hz) to avoid 50Hz frequency interference, but this method cannot eliminate the interference between the test leads, especially when the overhead line is used as the test lead, the error is quite large. After many field tests, this instrument has solved the interference of the power frequency current flowing into the ground grid and the interference between the test leads.

Technical Parameters Specifications :
(1) Power supply: AC220V±10%, f=50Hz
(2) Output current: AC 0.53A
(3) Output voltage: AC 0100V
(4) Measurement range: 0～4Ω
(5) Test frequency: 77.6Hz /116.4Hz (±0.1Hz)
(6) Measurement accuracy: ±(reading × 3% + 0.01Ω)
(7) Measurement line requirements: current line ≥ 1.5 mm2 voltage line ≥ 0.8 mm2
(8) Instrument weight: 7kg