Accelerated aging of XLPE cable insulation

The latest results of a continuing study into the deter ioration of cross-linked polyethylene (XLPE) insulation subjected to electric stress in the presence of water are described. Earlier results have shown that the breakdown strength of electrically aged XLPE was dependent on the amount of moisture in the insulation [1]. Temperature cycling has now been used to enhance water diffusion into the insulation and its effect on the breakdown strength and times to breakdown of miniature cables has been examined. Also the effect of fregency on the times to breakdown has been studied and is reported.