Grounding system design for isolated locations and plant systems

Abstract

Effective grounding is critical for protection of electrical equipment from transients. Grounding for personnel safety requires very distinct considerations. The application of the grounds may be similar in some instances. However, the installation will be radically different in isolated areas. Furthermore, the grounding of controls and computers present even more unusual requirements than the grounding of power devices. Additional concerns are circulating currents and injection of spurious noise. The paper addresses grounding for transients, power, and personnel. Designs include installations in plants and for isolated and remote equipment. The methods have been effectively used for pipelines, production facilities, gas plants, and power plants. Ten case studies of diverse applications illustrate the pertinence of the techniques and procedures. The case studies are: remote pump sensor erratic readings; unused data points inducing errors; remote sensor/input card failure during thunderstorms; data communication failure; blown fuses and data errors; conducting current flowing into grounding electrodes; fan motor failure; structural tower lightning strikes; high resistivity soil causing poor ground; and electrical shock when touching grounded metal enclosure.