Calculation of ground resistance and step voltage for buried ground rod with insulation lead

Procedures for installing ground rods can be categorized into the driven ground rod methods and the buried ground rod methods. The leads of ground rods are also classified into two types—bare conductor leads and insulation leads. The analytical results herein elucidate a method for determining ground resistance, earth surface voltage, position and magnitude of the maximum step voltage for the buried ground rod with the insulation lead. The ground resistance, earth surface voltage and step voltage in the driven ground method exceed those of the buried ground rod with the insulation lead. Ground resistance, earth surface voltage and step voltage decrease as the depth of the buried ground rod increases. The position of the maximum step voltage varies with the buried depth of a ground rod with the insulation lead. The distance of the maximum step voltage from the ground rod increases with the depth of the buried ground rod. Results of this study provide a valuable reference for ground designs that protect humans and electrical equipment.