Abstract:
The purposes of this research were to evaluate and analyze the differences in electrical conductivity in soil that affects the resistance of the grounding system. The research was carried out by using samples of conductor sizes in the soil, including numbers 50, 70 and 95. Three locations of the same size were selected for the experiments to get various parameters. The parameters were used as an element in determining the resistance of the grounding system in each location. Each location had three experiments using the different conductors. The averages of the resistance from the experiment in the three locations were found to be 9.34, 9.32 and 9.31 Ohms for the conductor numbers 50, 70 and 95, respectively. After using ANOVA, it was learned that the resistance of the three conductors were not different. Therefore, it was concluded from this experiment that the difference in the three conductors did not affect the ground resistance significantly. So, we can choose to use the conductor in the lowest size of the number 50, which was the minimum size that can be accepted. The price of the number 50 conductors was 229 Baht per meter. When compared to 450 Baht per meter for the conductor number 95, the first one was 221 Baht cheaper. So, the total reduction could be 49%.
Keywords: grounding system, conductor, ANOVA, cost reduced.