New technology breaths new life into old power lines
The Brooks Bulletin, May 2015
by Sandra M. Stanway
FortisAlberta is giving new life to 8.4 kilometres of 1970s installed underground power lines in Brooks by injecting them with a silicone-based liquid. “We’re putting a compound inside to increase the reliability of the system and to get its insulation value back up,” said Stephen Ricalton, a journeyman power line technician with Fortis.
The silicone injection is made into one end of a power line and forced through to the other end with 277 psi (pounds per square inch) of carbon dioxide. “It pushes the liquid into the insulation which fills all the voids, water trees and electric trees in it and rejuvenates the cable to make it last another 40 years,” said Ricalton.
As the work is being done the power remains energized except for the single cable being injected. “These guys are doing this project virtually live. We might have to take out outages at some point in time if there is a really bad splice and there’s no alternate feed,” said FortisAlberta spokesperson Mona Bartsoff. “Can you imagine how many back alleys we would have to dig up to replace the lines? The labour cost on that alone would be huge.” She added, the silicone technology is the most cost effective way to repair the old lines. “It costs onethird less that replacing the line,” she said.
The project is in its fourth year in Brooks but over the next three months the company will send silicone to over eight kilometres which is further than they did in the first three years. “For the last three years we completed five kilometres,” said Bartsoff.
“The first couple of years we were in a test mode. Now that we know it works and now that we know it keeps us from having to take outages for our customers and it’s the way to go, we’re full on,” she said.
The company should be completed by 2017 when they return to inject about three additional kilometres of power lines.