AC and lightning performance of fiberglass crossarms aged in 115 kV transmission line

This paper presents the results of an investigation of the electrical performance of 115 kV transmission line fiberglass crossarms used by Mississippi Power and Light Company. A transmission line fiberglass crossarm removed from service and companion crossarms stored outdoors but not in service were examined. The evaluation of electrical performance was based on flashover voltage value at AC voltage and standard lightning impulse as well as under dry and wet conditions. The tests were performed in the Mississippi State University High Voltage Laboratory. The obtained flashover voltages show no large difference in electrical strength of fiberglass crossarms removed from service and those stored outdoors. The added critical flashover voltage by fiberglass crossarm to the porcelain suspension insulators is presented versus the length of the fiberglass crossarm for dry and wet conditions. >