Stator winding hipot (high potential) testing

Over-potential or hipot tests are frequently applied to machine stator windings to assure that the electrical insulation in windings is fit for service. However, several questions are frequently raised: When should a hipot test be applied? Which hipot test should be applied? What should be the hipot test levels? Does hipot test damage a good winding? To answer these questions, a comprehensive review of literature was done and industry experts were surveyed for their views and experience under an EPRI sponsored project. The results are summarized in this paper. The questions are answered using the information from the literature review and the survey responses.