Electricity Today T&D Magazine

Field Testing of MV and HV cables has come a long way in recent decades. Gone are the days of old, when the traditional DC (Direct Voltage/Current) hipot was the recommended method for testing these modern cables that form the critical backbone of the distribution electrical power network. Extensive research, often rooted in the hard lessons learned through negative experiences in the field, has brought about changes to and improvements in the approaches and methods used when testing MV and HV cables.
The traditional high voltage “DC Hipot” and/or the routine insulation resistance measurement may still be a viable and useful technique for testing various types of electrical apparatus. However, when it comes to shielded MV and HV cables, this approach has been found to be seriously lacking and, in some cases, potentially damaging to the cables themselves. The latest IEEE400 clearly states that high voltage...