ABSTRACT
This chapter discusses Utility Distribution System Design and Characteristics. The distribution engineer sometimes finds it difficult to define a typical distribution system. This chapter suggests typical values of voltage, line lengths, load and fault levels, as well as types of system design and grounding which can be used as background information for the more technical discussions. The electric utility system is usually divided into three segments which are generation, transmission, and distribution. A fourth division, which can sometimes be made is subtransmission, which can really be considered a subset of transmission since the voltage levels overlap and operational and protection practices are quite similar. The distribution system is commonly broken down into the following three components: Distribution substation, Distribution primary and Secondary. It consists of a much wider variety of voltage levels, components, loads and interconnections than does the generation or transmission system.
