| Title |
Effects of the Position of Potential Probe on Ground Resistance Measurements Using the Fall-of-Potential Method |
| Authors |
Bok-Hee Lee ; Ju-Hong Eom ; Sung-Won Kim |
| Abstract |
The effects of the position of potential probe on the measurements of the ground resistance in the fall-of-potential method are described. The ground resistance is theoretically calculated by applying the 61.8[%] rule, and then the potential probe is located on the straight line between the grounding electrode to be measured and the current probe. However, sometimes the grounding electrode to be measured and the measuring potential and current probes in on-site test might not be arranged on the straight line with adequate distance because there are building, roadblock, construction and other establishments. Provided that the grounding electrode to be measured and the measuring potential probes are out of position on the straight line, the measurement of the ground resistance classically falls into an error and the measured ground resistance should be corrected. In this work, measurements were focused on the grounding electrode system made by the ground rods of 2.4 m long. The measuring error was increased with increasing the angle which is made by the 3-points of the grounding electrode to be measured, the potential and current probes, and it was a negative. That is, all of the measured ground resistances were less than the true ground resistance. |