Technical Evaluation of Test Procedures for Insulated Aerial Devices Rated Less Than 69 kV

Alternating-and direct-current test procedures prescribed by American (ANSI A92.2-1969) and Canadian standards (CSA C225-1976) are evaluated using analytical methods and test results. It is demonstrated that the alternating-current (AC) technique is not adequate to evaluate the dielectric integrity of insulated booms. The direct-current (DC) technique, offered as an alternative by the Canadian standards, generally allows evaluation of overall material quality but not the identification of local defects such as cracks, scratches, voids, etc. For the time being, however, the DC test procedure is recommended although for the immediate future, a research effort will be required to develop a technique for adequate electrical evaluation of insulated aerial devices.