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Penelec Rejuvenates Underground Cable to Help Enhance Service Reliability

July 15, 2020
Utility injected sections of an aging underground distribution line with a silicone-based fluid that should prolong its useful life by decades.

Penelec, a FirstEnergy Corp. utility, recently injected sections of an aging underground distribution line in Erie County with a silicone-based fluid that should prolong its useful life by decades. This method allows the cable to support continued reliable electric service for a fraction of what it would have cost to replace it and eliminates the need to dig trenches through landscaped yards and driveways for cable replacement.

Over time, water and corrosive soil materials can penetrate underground wire through tiny cracks and fissures, causing power outages. Rather than disturbing dirt to replace nearly 1.5 miles of aging underground cable along Fieldcrest Drive and Townsend Drive in Fairview Township, Penelec hired an electrical contractor that specializes in restoring buried cable without excavation.

This is the first time Penelec has used fluid injections to rehabilitate underground electric cable. The company may consider the process for more widespread application in coming years. The approximately US$80,000 project is part of the company's ongoing efforts to strengthen the durability of its electric system and enhance service reliability for its customers.

Accessing de-energized wires through underground vaults, the contractor forced pressurized silicone-based fluid into the cable, filling the cracks and spaces in the worn insulation encasing the wire with new material. The fluid provides a shot in the arm, strengthening the existing cable and helping it perform well for another 20 to 30 years.

"Underground electrical equipment is in many ways better protected from the elements than overhead wires, but when an outage occurs it often takes longer for our crews to pinpoint where the underground problem is and make repairs," said Nick Austin, regional president of Penelec. "The underground cable rejuvenation process only costs about half as much as replacing the cable — plus, it's far less time consuming and disruptive for neighborhoods."

Penelec plans to replace another 30,000 ft of aging underground cable in 2020. Much of that cable has been spliced and repaired too many times for those line sections to be good candidates for fluid injection.

The work is part of Penelec's Long Term Infrastructure Improvement Plans (LTIIP II), a US$200 million initiative to accelerate capital investments over five years to help ensure continued electric service reliability for the company's 585,000 customers.

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