Corrosion and fatigue failure of insulated copper conductors used for overhead power lines

The fatigue failure of copper conductors, covered by polyvinyl chloride; were investigated. It is demonstrated that corrosion pits, which are associated with the presence of chloride ions, are the focal points for subsequent fatigue fractures. Pitting and general corrosion are allied to movement of water and pollutants along the strands of the cable, although the surface decomposition of the PVC insulation cannot be completely ruled out as a contributor of chloride ions. The factors determining the rate and extent of corrosion are discussed. Various methods of preventing the premature failure of new or replacement PVC-covered conductor are considered