Whitehorse Daily Star

Power failure’s duration: seven minutes to three hours

Saturday’s grid-wide power outage lasted up to three hours for some 17,000 customers affected, but as few as seven minutes for others.

By Chuck Tobin on February 20, 2017

Saturday’s grid-wide power outage lasted up to three hours for some 17,000 customers affected, but as few as seven minutes for others.

Yukon Energy spokeswoman Janet Patterson said this morning the outage occurred at 3:08 p.m.

It happened after the failure of an electrical component on the largest hydro-generating unit at the Whitehorse Rapids Dam, commonly referred to as the fourth wheel.

It had been more than two years since the last grid-wide outage in 2014, also a result of problems with the fourth wheel, she said.

She said Stewart Crossing, Mayo and Keno City were the only grid communities not affected because of how the system’s protection system was built.

Altogether, there were 1,800 Yukon Energy customers affected and 14,960 ATCO Electric Yukon customers impacted.

Yukon Energy provides almost all the generation in the Yukon while ATCO provides most of the distribution.

In communities like Dawson City, Yukon Energy also provides the distribution.

Patterson said Dawson had power restored after 15 minutes with the back-up diesel generators, while Faro and Ross River were back on in 20 to 25 minutes.

They began re-energizing Whitehorse between 4:30 p.m. and 4:36, with ATCO handling the logistics of what sections of the city to bring back up first, Patterson said.

ATCO spokeswoman Carla Howard said today McRae and Granger were the first to be restored, with power back on at 4:39. The McIntyre subdivision was next at at 4:55, followed by parts of Porter Creek at 5:08, Whistlebend at 5:26, Riverdale at 5:31, Mountainview 5:37, Arkell at 5:42, the downtown at 6:04 and Yukon College and the remaining part of Porter Creek at 6:06.

Other communities like Teslin and Pelly Crossing were restored in seven minutes with back up diesel generators in their communities, Howard said.

Patterson said they had to rely on one natural gas generator at the dam for a few hours while the fourth wheel was down but they started bringing the fourth wheel back on line at 8 a.m. Sunday.

“By 9:30, it was running as normal, and it’s on the system now and its running as normal,” she said.

Patterson pointed out the part that failed had already been scheduled for replacement in April, and discussions about conducting a major overhaul of the 1980s-era fourth wheel this summer were already underway before Saturday’s outage.

She said it was all hands on deck for Yukon Energy on Saturday, as there was a crew of 24 working on the restoration.

Comments (2)

Up 20 Down 3

Highly Suspicious! on Feb 20, 2017 at 5:15 pm

Strange that this system wide outage comes at a time when Yukon Energy is ramping up for another unwarranted rate increase. A little public conditioning never hurts when your trying to argue that the power system doesn't meet demands even though we just purchased 2 huge gas generators that much to everybodys surprise, do not automatically provide the demand juice. (Seems like a mistake). YE will be arguing that they need way more funds even though they just got a 13% increase and are back at the trough already. (Campaigning).

Up 14 Down 4

Isembard on Feb 20, 2017 at 4:11 pm

Total Preventative Maintenance - try and drag yourself into the 21st Century !

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