Effects of voltage surges on extruded dielectric cable life project update

Electric utility engineers have commented that extruded distribution cables frequently fail during or shortly after a thunder storm. These engineers also comment that failures often reoccur on cable circuits where previous failures were located with a thumper. Linemen at Georgia Power often make similar comments. To investigate this observation, crosslinked (XLPE) and tree retardant crosslinked (TRXLPE) power cable designs were subjected to accelerated water treeing tests. Samples were subjected to simulated lightning surges or simulated thumping surges. Crosslinked cables removed after 15 years of service operation were also subjected to these surges. The results show that, in some cases, lightning surges do reduce extruded distribution cable life. Also, high level thumping surges appear to reduce cable life once cables are well aged