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.

Jul 30 2012

Stone in Cable 176m (578ft) from Termination

By: Ben Lanz and Bill Corrente

Posted in: Backfill, Cable, Facility, Generation, Renewable, Solar, Utility, Wind, Workmanship

 

IMCORP’s  Factory Grade® assessment discovered a substandard  location while commissioning the cable systems at a generation facility. The client used IMCORP’s Location Matching service to pinpoint the defect location. No physical evidence was found upon first glance.  Looking at the cable jacket more closely, the field technician noticed a small dimple of dirt that appeared to be pushed into the cable.  The installation contractor cut open the jacket and revealed a sharp stone that punctured the jacket and outer semicon layer of the cable (picture above). The stone was a stress enhancement that also created an interfacial void.  Mostly likely this damage to the cable insulation would have resulted in a near term failure if left undetected and not repaired.