The question of whether or not to ground a power system is one which must be faced sometime by most engineers charged with planning industrial distribution. A decision in favor of a grounded system leads then to the question of how to ground.
It is the intent of this chapter to assist the planning engineer to answer these and other more detailed questions on the subject, by presenting basic reasons for grounding or not grounding and by reviewing general practices and methods of system grounding. Practices of the grounding of synchronous generators, and for the grounding of transmission systems, particularly those operated at 23 kilovolts and higher, have been summarized in other guides. The practices set forth in those guides are applicable to industrial power systems in various degrees, depending on the type and extent of the industrial system under consideration, and on the character of service required at the points of power consumption.
Where an industrial power system consists of power generating equipment, transmission circuits, and distribution circuits, the reasons for grounding these components are often the same as for grounding similar components of public utility systems and other large power systems, and the methods of grounding would generally be similar under like conditions of service. But in some cases the reasons for grounding and the methods of grounding certain components of an industrial power system may differ according to the requirements of manufacturing or process operations.