ABSTRACT
Figure 7.1 depicts a typical power distribution system. The township power comes from transmission lines via a step-down substation transformer shown in the dotted box. It shows four three-phase feeders running radially from the central distribution station switchboard to various loads via circuit breakers. Feeders 1, 2, and 4 are shown in a single-line diagram, whereas Feeder 3 is shown in full detail with four-wire configuration (three-phase lines A, B, and C with neutral N). The lateral feeders are tapped off from each phase (line to neutral) of the main feeder such that single-phase service loads are about equally distributed on all three phases of the system. For example, the first two topmost lateral feeders-one going to the left and one going to the right-take power from phase A, the next two lateral feeders take power from phase B, and the next two from phase C.
