Is Modern High Voltage Testing Destructive?
A published survey (2001) of utilities routinely performing High Voltage testing was the source of this information: Does HiPot testing damage a good winding? This question is raised many times, most often by managers, who have to approve the tests. The answer is a resounding NO. HiPot tests do not introduce any significant degradations in a machine with a good insulation system. Machines that have failed a HiPot test have ALWAYS revealed poor insulation systems upon later examination.5 Modern High Voltage test equipment has many built in instantaneous trips, which simply did not exist 20 years ago. As an example, the over-current trip function of modern Baker Instrument Company equipment can be activated with less than 1 micro-amp of leakage current. The Maintenance Engineering Handbook 6th edition 2002 is even more descriptive: The surge test is a method for evaluating turn-to-turn insulation within the coils. THIS IS A NON DESTRUCTIVE TEST which indicates shorts and dissymmetries su
