Electrical considerations in establishing working clearances for energized line maintenance

Information on factors affecting the electrical performance of large gaps has led to concerns regarding the adequacy of clearances used for live line work. The ESMOL Working Group on Safety reviewed the factors which affect the electrical component of the phase-to-ground working clearances. These factors are reviewed and areas are identified for further research necessary to relate line designs based on operating performance criteria to live line working conditions. Particular consideration is given to the following factors: voltage stress at the work site, work site insulation strength, the atmospheric effect, and minimum clearance requirements