Large Ground Grid Earth Resistance Tester GRT-III

Now in the power system, the most popular measurement for grounding resistance of large ground Grids is “Three Pole” method using 50Hz power-frequency large current. In order to avoid interference from 50Hz power-frequency in power grid operating and improve veracity of measuring, the insulating precaution test regulation stipulates that test current of 50Hz power-frequency large current measurement must be less than 30A. As a result of the regulation, there have some problems such as the heavy test device, large labor, and long test time.

 GRT-III survey meter for grounding resistance of large ground grids is an all-purpose tester with electrical source of non-power frequency, the tester can measure the grounding resistance of substation (4Ω), thermal power planthydropower plant, microwave station (10Ω), lighting rod etc. Microcomputer is adopted to control GRT-III survey meter and process testing datum, which eliminates interference from the testing process, simplifies operation programs of testing, enhances precision and veracity of measuring, and reduces the cost of labor and test.

Technical parameters:
1) Measurement range:  0~40Ω
2) Precision: 3%
3) Output current: AC<5A
4) Diameter specification of testing wire:≥1.5mm2
5) Electrical source: AC220V/50Hz
6) Weight: 5kg