A review of overhead secondary distribution

This paper provides a comparison of results of 5 economic studies^∗ that were made to determine the economic relationship between conductor sizes and distribution transformer sizes for various load densities and rates of load growth. The progressive method of distribution design, which provides additions rather than replacements, has been found most economical. Increase in load density can be handled most economically by the subdivision of secondary mains and the installation of intermediate transformers. Numbers 4, 3, or 2 conductors and 15-kva transformers should be favored for overhead secondary distribution in residential areas in cities and towns. Rural lines and service to rural communities are not considered in this comparison.