Electrical performance of 115 kV transmission line fiberglass crossarm used by MP&L

The authors present the results of an investigation of the electrical performance of 115 kV transmission line fiberglass crossarms used by the Mississippi Power & Light Company. Three 115 kV transmission line fiberglass crossarms removed from service and three identical ones were examined. The evaluation of electrical performance was based on flashover voltage value at AC voltage and standard lightning impulse. Flashover voltages were measured under dry and wet conditions. The impulses used in the tests had positive polarity. The obtained flashover voltages showed no large difference in the electrical strength of fiberglass crossarms removed from service and those stored outdoors.<>