Discharge damage and failure in 11-kV belted cables

Investigations of a particular type of failure of 11-kV oil/rosin impregnated belted cables are described. These failures, encountered both in South Africa and other countries including the United Kingdom, have invariably been found in a vertical run of the cable close to an end box and the cable papers in the region of the failure have usually shown severe “pin-holing“, without charring, together with waxing and loss of compound. In addition, corrosion products have frequently been found on the copper conductor strands.