Defect Blog

Each year, millions of people and thousands of businesses are impacted by underground cable system failures. IMCORP is dedicated to advancing the understanding of how these failures occur and more importantly, how they can be avoided.

Mar 23 2012

Whittled Cutback on Power Cable at a Co-op Utility


Posted in: Workmanship, Wind


This image shows a 7.2 kV (medium voltage) power cable system at a co-op utility in rural Missouri that supplies power to a residential area.  IMCORP's Factory Grade® assessment indicated PD activity at the separable connector of this particular cable system. Upon further inspection, IMCORP determined that the cable was not IEEE 386 compliant. The semi-conductive material was not prepared in a smooth radial cut pattern (as is required) but rather in a jagged, non-uniform way. In addition, the insulation between the semi-con and the stress relief element (elbow) had been haphazardly gouged and whittled down. The stress relief at the termination is dependent upon proper semi-con cutback and insulation. If this issue were not caught in advance by IMCORP and promptly mitigated, the utility’s customers may have experienced power outages as a result of a termination failure.