Mathematical study of voltages between sheath and cable conductor due to currents from nearby earth electrodes

The voltage between a sheath and a cable conductor which is excited by the current leaving a nearby earth electrode is considered. Point, parallel and perpendicular earth electrodes are discussed. The maximum voltage between the sheath and the cable conductor is evaluated, and the functions which appear in the equations for the maximum voltage are plotted. The effect of variations in the internal impedance of the cable sheath and in the earth conductivity is considered.