IMCORP

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.

Aug 08 2012

Termination Failure at a Wind Farm

By: IMCORP

 

This client used Factory Grade® technology to commission a shielded power cable system, linking a substation with a generation plant. We found twelve cable terminations on the substation end of the circuits performing well below the manufacturers’ specifications. The contractor, being unfamiliar with the latest diagnostic technology and manufacturers’ standards, insisted that the terminations were installed correctly. In an effort to vouch for the quality of the system, the contractor performed an IEEE Type 1 VLF 0.1Hz Destructive AC HiPot on all of the cable systems in question. All cable systems passed the VLF AC HiPot.

However, within one month there was a failure on one of the terminations recommended for repair by the Factory Grade® technology.  Looking at the image above (One Month Later), you can see that the stress control was not in contact with the semicon. The plant owner then requested that the contractor repair all of the terminations reported as substandard by IMCORP.