The function and composition of the global industrial grounding system

This paper describes the basic functions of, and the parts that make up, the global grounding system. It discusses the destructive effects on equipment and the danger to human life presented by the existence of high-frequency lightning-surge currents in the earth or ground. Emphasis is on the important role of the global grounding system in minimizing the attendant hazardous voltage gradients that occur in the ground surface. The effect of 60-Hz-frequency ground-fault current in seeking a path in closest proximity to the outgoing power conductors within its ground-fault island is asserted. The operation of wye-delta-wye transformers to interconnect a resistance-grounded industrial system to a solidly grounded high-voltage utility system is explained without the customary utilization of symmetrical components.