Shielding 13.8-kv distribution circuits

THE DISTRIBUTION SYSTEM for all new residential and commerical areas developed in New Orleans since 1943 has been constructed to operate at 13.8 kv with conversion of the old 4-kv system to 13.8 kv beginning in 1945. The use of 13.8-kv circuits raised the distribution lines above the surrounding shielding, thereby increasing exposure to lightning. As more and more of the 4-kv circuits were converted and the 13.8-kv system expanded, this exposure continued to increase, resulting in an increased number of circuit outages during thunderstorms. Since New Orleans is in an area that can expect 75 thunderstorm days per year, some steps had to be taken to reduce the increased exposure.