The effect of electrical grounding systems on underground corrosion and cathodic protection

THE essential purpose of most electrical grounds is protection. The National Electrical Code states that: ¿Circuits are grounded for the purpose of limiting the voltage upon the circuit which might otherwise occur through exposure to lightning or other voltages higher than that for which the circuit is designed: or to limit the maximum potential to ground due to normal voltage.¿1 It states further that exposed metal enclosing electric conductors or enclosing electric equipment are grounded for the purpose of preventing a potential above ground on those enclosures. While there are other purposes for electrical ground, such as those which are required in the communication field, most grounding is done for protection either of equipment or of personnel. Even static grounding at oil or gasoline unloading facilities is a protective device.