LOW-TEMPERATURE AGING OF XLPE AND EP INSULATED CABLES WITH VOLTAGE TRANSIENTS

This paper presents the interim results of tests conducted on 15 kV cr osslinked polyethylene (XLPE) and ethylene propylene (EP) insulated ca bles aged under identical conditions for 36 months at 30 degrees C (+/ -5 degrees C) with and without applied voltage transients. Aging volta ges were from 1 to 2.5 times rated voltage, Failures during aging have occurred in EP insulated cable while none have occurred in XLPE insul ated cable. Both types of cable experienced a large drop in ac and imp ulse voltage breakdown strength early in the aging process. There is a n indication that voltage transients have slightly affected the ac and impulse voltage breakdown strength and contributed to the EP cable ag ing failures.