Sami .Ajeel; Mokdad T.Younis; Arkan A.Hussein
Abstract
This work involves fiberglass samples used in two kind of aging (45days aging, 45 days aging with AC of 25 kV). Five sets of fiberglasssamples were used in the accelerated aging tests ...
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This work involves fiberglass samples used in two kind of aging (45days aging, 45 days aging with AC of 25 kV). Five sets of fiberglasssamples were used in the accelerated aging tests and each set consists ofnine fiberglass samples. The tested insulation length of these samples waschosen as 0.3 m. Two metallic bands, upper and bottom, were used aselectrodes and tightly wrapped on the samples. The effect of surfacecondition on the materials electric degradation was studied and the ninesamples were divided into' three group. The external surfaces of the firstgroup of tested samples were kept intact, but some scratches were manuallyplaced on the external surfaces of the second group. For the third group, fiveholes, each with 2.5 cm in diameter, were manually drilled in each sample.The electric experimental using to identify the insulation strength offiberglass materials were (the lighting impulse test, AC wet flashover testsand, AC dry flashover test).The result show that the CFO voltage and ACflashover under dry condition were higher than under wet condition for allsamples. The leakage current has a linear relation ship with applied voltage.The electric degradation is significant when the sample were tested withelectric stress.
