An overview of different designs of water resistant cable

An overview of the most current information on several different constructions and materials that help combat water treeing, a long-term failure mechanism for extruded dielectrics is given. The mechanisms involved in tree formation and in the subsequent deterioration of the insulation material are described. The use of accelerated cable life testing to evaluate different methods of coping with treeing is discussed. In the ACLT, test conditions accelerate the growth of trees. The compounds normally used as the insulation for medium-voltage cable, namely, crosslinked polyethylene (XLPE), tree retardant crosslinked polyethylene (TR-XLPE), and ethylene propylene rubber (EPR), are compared. It is shown that under testing the EPR compounds last much longer than TR-XLPE and standard XLPE.<>