Grounding of Distribution Systems

Electrical shock hazards can exist in many situations where there is no direct contact with any electrical conductors or equipment. This chapter discusses some of the hazards which are produced by electrical utility distribution systems. There are a variety of distribution systems in the world, with different voltages, grounding configurations, numbers of conductors, and so forth. The chapter, in particular, addresses mostly the multigrounded neutral system prevalent in North America. It begins with a discussion on the typical electric utility distribution system for homes and farms in the United States, and the domestic wiring system that it feeds. The flow of currents for both unbalanced loads and ground faults are estimated, along with the voltages that are associated with the currents. The level of hazard for various configurations is calculated. The chapter concludes with a discussion on the methods of remediation.