Water content of XLPE cable components

This paper presents results of water absorption measurements in several insulation and shield materials taken from unaged medium-voltage cables made by three different manufacturers. Comparisons are made of the water content of two types of water tree retardant XLPE (WTRXLPE) insulation with a conventional XLPE material, and two cleaner conductor and insulation shields with conventional ones. The measurements were performed on cable component chunks after immersion in water at 23, 57 and/or 80°C for various periods of time. The results show that the new cable components absorb much more water by a factor between 2 and 14. Furthermore, the capability of WTRXLPE insulation to retain and/or release water at normal operation temperature (90°C) is also reported: this parameter provides an indirect indication of whether these materials lose their effectiveness with time