Fog-type insulators eliminate transmission line flashovers

ACCORDING to A. C. Nielsen Company, engineers, Chicago, and J. E. Woods and E. T. Ankele, respectively chief engineer and operating engineer for the Central Power & Light Company, San Antonio, Texas, Lapp standard fog-type insulators have been instrumental in solving a troublesome transmission line problem on the power company's 17-mi., 66-kv. transmission line between Sinton and Robstown, Texas. The line in question is subject alternately to dust and salt fogs, and for some time prior to its reinsulation there occurred an average of some ten insulator failures and consequent service interruption. Analysis of maintenance costs showed an average expenditure of of $152.50 annually to cover necessary replacements, and this together with troubles arising from interruptions to important service brought about a reinsulation which was completed about two and one-half years ago. At that time the 66-kv. pin-type units previously in service were replaced each by three No. 5805 fog-type units. It is stated that insulator failures due to arcover have been eliminated entirely.