Subdivision underground repair and replacement ongoing

Hydro outages inevitable, but should be shorter as infrastructure rebuilt

A civil contracting crew laid ducting down in the underground electrical system on North Birch Avenue on March 17

A civil contracting crew laid ducting down in the underground electrical system on North Birch Avenue on March 17

The power outage and the underground repair and replacement work in parts of 100 Mile House went off as planned on March 17.

The power was flipped off at 9 a.m. and it was turned back around 6 p.m.

The outage affected 215 Evergreen Cres. to North Birch Avenue; Birch Place; Balsam Street; Fir Street; and from 267 and 262 Dogwood Cres. up to Balsam Street.

BC Hydro design technician Ingo Theuring of the l00 Mile House office says he was pleased how the upgrade went.

“It’s a 1970 or so vintage, so some of the infrastructure that is there now has passed its lifetime and it needs upgrading.”

Underground work is a bit more involved because back in the 1970s they didn’t have the standards they do now, Theuring says, adding they have to do a lot of prep work and then upgrade equipment in sections.

“With there not being standards, there’s not really a safe way to operate equipment, so we were trying to incorporate that in the new design. This was really the first stage.”

He notes the driver of the current work was the transformer was being lifted by tree roots and it was only a matter of time before it would fail because it would put more strain on the wires.

Theuring says the underground primary wire carries 14,400 volts and it could cause some real damage.

“It was going to be a hazard to people or cause an even longer power outage [than the March 17 outage].”

In all, a low profile transformer was replaced and junction boxes, which the primary wire runs into and allows the power to be safely switched off, were installed on each side of the transformer. Theuring explains this will allow power to be turned off, but not involve as many households.

The junction boxes were installed at the corner of Evergreen Crescent and North Birch, and at North Birch. Service boxes, which go to the houses, were also replaced.

“The civil contractor placed all of the junction boxes in the ground and used the vacuum truck to lay new duct in the ground. Then our crew pulled the new cable through and terminated them at each end, and they replaced the low profile transformer and connected it all up again.”

Theuring says the next phase will be installing more junction boxes throughout the subdivision.

“So, we can have a section off – maybe five houses instead of 10 – and renew everything without having everyone off while we do the work.”

Back in the ’70s, he explains, the primary line was run in one long line, so as it deteriorates, BC Hydro cannot work on sections of it safely without shutting off the whole line.

BC Hydro also has to replace a terminal pole, which is where the overhead lines drop down to the underground system, in the next phase.

After that, each low profile transformer will be replaced as they work through the system. Those replacements will be determined the ones that are in worse shape.

“There is another one being lifted up by roots a little bit. I would think we’ll replace them and bring everything up to standard as much as we can.”

Theuring says the length of time for future outages will be determined by the status of the old primary line, which is brittle and reaching the end of life. He suspects they will be able to turn the power off to half a subdivision at a time.

Given possible budget constraints, Theuring says he hopes the whole subdivision can be completed this year.