Service aged medium voltage cables-a critical review of polyethylene insulated cables

Utility organizations have major investments in underground distribution facilities to provide electrical service to their customers. Medium voltage cable is a major component of these distribution facilities. Over the years since residential subdivisions have been served with underground electric systems, there have been many insulations sold to the utilities. There has now been sufficient time for these cables to have aged naturally and data is becoming available to evaluate each of these insulations. This work will describe the various polyethylene insulations that have been available over the past 35 years and give the actual performance of these materials. The data indicates service life estimation among these insulations. A follow up paper will provide the same critical analysis of the various ethylene propylene rubber insulations that have been used over the same period.