Corrosion attack in midspan joints in ACSR transmission conductors

In conjunction with the investigation of midspan transmission line conductor joints that have been dismantled because they exhibited excessive resistance, it was discovered in most cases that severe corrosion attack had occurred in them. The attacks were concentrated in the areas where the steel core enters the steel joint sleeve. Corrosion was discovered in conductor joints on 130 kV to 400 kV lines. Various methods of inspection have been tested to determine the extent of this corrosion and protect conductor joints from further attack.