Application of Spill Gaps and Selection of Insulation Levels

Abstract

Synopsis SHIELDINGShielding of circuits and equipment is accomplished Thi ppe pesnt' fo thviw inofhengeer ether by underground construction, or by the so-called who plans and operates electric power systems, the appli-eithe nb u round construction, or be so-calle cation logic or theory and the performance results w*th " p t wfoi ir the shielding must be capable of withstanding all direct variousufomsn frof spi tgaps, for theprotection of circuit strokes of lightning, except possibly the most severe, and equipment from lightning, and the selection of insula-wihu braoe or codcino h ihnn urn tion levels co-ordinated with this type of protection. tothe pow erond cors.to the power conductors. The performance results are largely confined to transShielding within the limitations of the specific installamission voltages, although the same general principles tion, protects service and equipment. Unfortunately it and logic apply over the entire transmission and distribu-is economically feasible only in the case of the higher transtion operating voltage range. mission voltages, and on circuits of major importance.In the lower transmission and distribution range of Background