Primary Distribution

Primary distribution systems deliver electrical power from substations to consumers through various voltage classes, with 15-kV class voltages being predominant among U.S. utilities. Older 2.5- and 5-kV classes are being replaced by 15-kV primaries, while higher 25- to 34.5-kV classes are used in high-density urban areas and rural regions with l...

The primary distribution system facilitates the transmission of electricity from high-voltage transmission lines to consumer-end distribution transformers.

The primary radial system, most prevalent in low-load density areas, consists of individual three-phase feeder mains.

Lightning flashovers or momentary contact incidents can cau...