Investigation on Wear due to Corrosion of the Earth Electrode and the Rate of Increase in Earth Resistance

This paper investigates the rate of increase in earth resistance due to corrosion of the earth electrode. When the earth electrode corrodes, the predetermined value cannot be maintained due to the earth resistance increasing. As there has been no study of the relationship between corrosion of the earth electrode and earth resistance, it is difficult to predict the rate of increase in earth resistance due to electrode corrosion. In this paper, we have derived a calculation formula for determining changes in electrode shape that takes both electrolytic corrosion and natural corrosion into account, and this makes it possible to estimate the lifetime of the earth electrode. Furthermore, by using this calculation formula, it is possible to predict the rate of increase in earthing resistance value when electrolytic corrosion and natural corrosion progress simultaneously.