This report deals with dielectric tests on completed apparatus. Tests on materials and on components during the course of fabrication usually are left to the discretion of the manufacturer and are not a subject foe standardization except as to method and technique. Impulse test values where specified in standards are based on the Basic Impulse Levels and thus are consistent for different equipment. Impulse test conditions and technique are outside the scope. Hence, this report deals mostly with conditions and test values associated with low-frequency dielectric tests.

This report deals with dielectric tests on completed apparatus. Tests on materials and on components during the course of fabrication usually are left to the discretion of the manufacturer and are not a subject for standardization except as to method and technique. Impulse test values where specified in standards are based on the Basic Impulse Levels and thus are consistent for different equipment. Impulse test conditions and technique are outside the scope. Hence, this report deals mostly with conditions and test values associated with lowfrequency dielectric tests

A statement of the purpose of this report follows from this review of the general problem. It is: (1) to present a survey of the over voltages encountered in service (2) to review existing test values and practices in present standards (3) to propose guiding principles for the selection of dielectric test values (4) to investigate other types of testing to determine their latent usefulness and the desirability of standardization.