IMCORP Blog

Oct 28 2015

PD Activity Identified During Assessment of Aged Utility Cable

By: IMCORP

Posted in: Utility, Cable

During the reliability assessment of aged underground residential distribution (URD) cable systems at a mid-western electric utility, one particular cable sample was found to exhibit low levels partial discharge (PD) activity. These PD sites were evi... Read Article


Oct 27 2015

Very Low Partial Discharge Values Found While Commissioning A New Wind Farm

By: IMCORP

Posted in: Workmanship, Wind, Utility, Renewable, Cable

During a recent wind farm commissioning project in the southern United States multiple defects were identified within the collector cable system. One particular cable exhibited defects in the form of very low levels of partial discharge at two times ... Read Article


Dec 18 2014

Wind Farm Cable with a Small but Very Serious Defect

By: IMCORP

Posted in: Workmanship, Wind, Renewable

After performing an initial Factory Grade® technology assessment at a renewable energy plant, a cable was found to have near end termination discharge at operating voltage. The on-site crew attempted to mitigate the Partial Discharge (PD) activit... Read Article


Nov 18 2014

Oil Damaging to Cable Semicon

By: IMCORP

While performing a Factory Grade® technology assessment on a cable at a utility client in the southern part of the US, substandard partial discharge (PD) was observed near a termination. Upon visual inspection it was noted that the cable&r... Read Article


Nov 18 2014

Cable Manufacturer’s Defect Found at a Renewable Site

By: IMCORP

As part of commissioning of a new renewable energy site in the Midwest, IMCORP's Factory Grade® technology assessment was performed on the entire site cable collector system.  Substandard partial discharge (PD) activity (per I... Read Article


Feb 05 2014

Severe Termination Damage at a Utility

By: IMCORP

An IMCORP Field Engineer was performing a Factory Grade® technology asessement for a utility client. The test results showed partial discharge (PD) at operating voltage in the far end open air termination. Upon investigation of the far... Read Article


Feb 05 2014

Multiple Defects Found at a Wind Farm

By: IMCORP

Just a few weeks ago, IMCORP was performing its Factory Grade® technology assessment at a wind site in Canada. The test indicated substandard partial discharge (PD) at the near end termination. To determine the source of the PD, the as... Read Article


Sep 23 2013

Carbon Black Residue at a Utility Cable Termination

By: IMCORP

IEEE 386 Non-Compliant   While performing IMCORP's Factory Grade® technology assessment for a utility client, IMCORP detected sub-standard partial discharge (PD) activity at a URD cable termination. After the assist... Read Article


Sep 20 2013

Damaged Semicon at Termination at a Wind Farm

By: IMCORP

IEEE 386 Non-Compliant While commission testing a renewable energy generation site, IMCORP’s Factory Grade® technology assessment found partial discharge(PD) activity near a T-body termination. Visual inspection of the terminati... Read Article


May 13 2013

Issues with Termination at a Utility

By: IMCORP

IEEE 386 Non-Compliant Earlier this year, IMCORP was performing its Factory Grade® technology assessment for a utility client and detected PD at 1.3 times operating voltage at the far end termination (not meeting IEEE 386 requi... Read Article


Mar 20 2013

Electrical Tree in an Aged XLPE Cable

By: IMCORP

Electrical Tree in Aged URD Cable A few years ago at a client utility in the Midwest, IMCORP was performing a Factory Grade® technology assessment on an aged 2615 foot long XLPE cable.  As the high voltage portion of the test w... Read Article


Mar 19 2013

Ambers in Cable Insulation at a Renewable Generation Facility

By: IMCORP

Cable not meeting ICEA S-94-649 standard A little while back at a renewable energy generation facility, IMCORP was conducting a Factory Grade® technology assessment on collector system cables when this pair of defects was uncov... Read Article


Sep 27 2012

Severe Cable Defect at a Wind Farm

By: IMCORP

Cable not meeting ICEA S-94-649 standard In 2012, IMCORP was again contracted to commission a wind farm collector system using  Factory Grade® technology.  During the course of testing, the IMCORP Field Supervisor came acros... Read Article


Aug 15 2012

Improper Installation of Stress Control

By: IMCORP

When: November 2011 Where: Wind farm in West Virginia. The owner of this wind farm had IMCORP perform testing on their aged cable systems in the past. However, for new cable installations they chose to use VLF testing. Within one year of in... Read Article


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 to be performing well below ... Read Article


Jul 30 2012

Improper Insulation Cutback On A Cold Shrink Termination

By: IMCORP

The above image; taken at a nuclear power plant in Southeast USA, shows a jagged cutback on an open-air cold shrink termination. During a cable system installation, the utility used Tangent Delta (TD), Very Low Frequency AC destructive wit... Read Article


Jul 30 2012

Nail in Cable 578ft From Termination

By: IMCORP

In November 2011, the IMCORP  Factory Grade® technology assessment discovered this compromised section of cable at a wind farm in Kansas. The customer used IMCORP’s Location Matching service to pinpoint the defect location. ... Read Article


Jul 23 2012

PD Activity in a Y Joint at a Nuclear Facility

By: IMCORP

Posted in: Workmanship, Generation

In 2008, IMCORP conducted its Factory Grade® technology assessment on a critical loop at a government nuclear facility in southeast USA. This particular PD occurred at a Y-joint located 185 ft. and had an inception... Read Article


Apr 16 2012

Non Radial Cutback on a Cold Shrink Joint at a Wind Farm

By: IMCORP

Posted in: Workmanship, Wind, Generation

This cold shrink joint was a part of a feeder cable system at a wind farm site that failed to pass IEEE 404 specifications. Even after the Factory Grade® technology assessment found this joint to be substandard, the cable system... Read Article


Apr 16 2012

Non Radial Power Cable Cutback at a Power Plant

By: IMCORP

This is the open-air termination of a solid dielectric cable featuring ethylene propylene rubber insulation (the salmon colored section). Initially, this cable was deemed to be in good working order after passing a one-hour, 3Uo VLF withstand tes... Read Article


Apr 16 2012

Misplaced Stress Relief Material at a Utility

By: IMCORP

Posted in: Workmanship, Utility

This particular open-air termination transitions an underground line to a riser. Although visual inspection indicated that the cable was properly installed (it is difficult to see the mastic placement with the termination installed), the cable ... Read Article


Mar 27 2012

Embedded Semicon in Insulation during Cutback at a Wind Farm

By: IMCORP

Posted in: Workmanship, Wind, Generation, Cable

The cable displayed here was compromised as a result of the misuse of an insulation-stripping tool when being installed at a wind farm. At the insulation cutback, the contractor had inadvertently cut too deep, resulting in a small slice of semi-c... Read Article


Mar 23 2012

Issues Performing Cutback on Out of Round Power Cable at a Wind Farm

By: IMCORP

Posted in: Workmanship, Wind, Generation

Featured here are medium voltage feeder cables at a wind farm substation in South Dakota. These cables are the site’s most critical link, handling the output of 10 to 20 turbines. IMCORP Factory Grade® technology found that ... Read Article


Mar 23 2012

Improper Heat Shrink Application on Power Cable at a Wind Farm

By: IMCORP

Posted in: Workmanship, Wind, Generation

These images show the development (from November 2008 to March 2009) of a medium voltage cable failure in an open-air termination at a wind farm in Minnesota. The first image shows non-compliant heat shrink at the termination that was located b... Read Article


Mar 23 2012

Power Cable Degassing

By: IMCORP

Posted in: Workmanship, Wind, Generation

These images show cross-sections of a medium voltage power cable that was installed at a wind farm in Wyoming. In this case, the IMCORP Factory Grade® technology indicated partial discharge activity on a section of cable. The PD l... Read Article


Mar 23 2012

Damage to Power Cable from a Neutral Wire Repair

By: IMCORP

Posted in: Workmanship, Wind

IMCORP's Factory Grade® technology assessment indicated a PD site in an underground medium voltage power cable at a wind farm in Texas. Initial inspection of the PD site did not show any evidence of an issue. IMCORP's confiden... Read Article


Mar 23 2012

Whittled Cutback on Power Cable at a Co-op Utility

By: IMCORP

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® technology assessment indicated PD activity at the sep... Read Article


Mar 23 2012

Power Cable Termination Cutback Issues at a Data Center

By: IMCORP

Posted in: Workmanship, Facility

Pictured here are live front terminations of a 7.2 kV (medium voltage) power cable system at a critical data center in Portland, OR.  After termination failures began to occur, DC HiPot testing had been utilized but came back inconclusive. A... Read Article


Mar 23 2012

Power Cable Damage From Backfill

By: IMCORP

Posted in: Wind, Generation, Cable, Backfill

These images show a PD site in a medium voltage power cable, part of a collector system designed and installed at a wind farm in Idaho during 2005.  In the first few years of operation, the site experienced a very high collector syst... Read Article


Mar 23 2012

Power Cable Termination Cutback Issues at a Wind Farm

By: IMCORP

Posted in: Wind, Generation

These pictures show two different live front substation terminal ends at a wind farm in Canada during the summer of 2006. The client believed that the medium voltage power cable termination ends at the substation were in fine working order. Also, e... Read Article


Mar 23 2012

Power Cable Insulation Damage (Sabotage) at a Wind Farm

By: IMCORP

Posted in: Workmanship, Generation, Cable

                          The discovery of this medium voltage power cable defect at a site in Canada during the summer of 2006 provided an ... Read Article


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