A-C and D-C high-potential testing

Insulation is recognized as the weak link in the chain of electrical reliahility despite the tremendous strides of the past few decades. Improvement in insulation and in test methods is suggested. A-c and d-c testing procedures are compared, and advantages and disadvantages of each, in particular test situations, are analyzed. Methods for determining the size of the test set for a particular application, a-c to d-c conversion factors, and several techniques of performing d-c tests are outlined.