A tree blown onto a power line by Friday afternoon's powerful winds knocked out electricity to about 400 customers.

Jay Massie, superintendent of operations for Yukon Electricial Co. Ltd., said today the McIntyre, Logan and Arkell subdivisions and part of Copper Ridge were blacked out just before 4 p.m.

Electricity was restored to Logan, Arkell and Copper Ridge by 5 p.m., and McIntyre was back on at 5:20 p.m., he said.

Massie said a tree was blown onto the line running through the bush from the substation near Rabbit's Foot Canyon to the McIntrye subdivision.

"It did not do any damage to the line, but the tree had to be removed by the guys."

Down at the Whitehorse Rapids Dam, meanwhile, Yukon Energy has put the number three hydroelectric turbine back on line, eliminating the need to use its diesel generators during periods of peak demand.

An expert in the field of generators arrived in Whitehorse last week from Wisconsin to assist Yukon Energy with its assessment of the number three and four turbines.

"Number three has been back on line since 17:52 (5:42 p.m.) Friday afternoon," Yukon Energy spokeswoman Janet Patterson said this morning.

She said an inspection of number three didn't show anything wrong mechanically, so it was recalibrated to the same safety setting typically used by the Wisconsin company.

The safety settings, Patterson explained, will automatically shut down the generator if problems are detected, to avoid any significant damage.

Number three was tested, and put back on line Friday afternoon, she said.

"And it has been working fine ever since," she said. "Now they have turned their attention to number four."

Number four has been off line since Thanksgiving Sunday, when a faulty valve caused a lengthy blackout of the entire Whitehorse-Aishihik-Faro grid.

Patterson said Yukon Energy now suspects problems with number three may have contributed to the lengthy outage on Thanksgiving Monday.

The publicly-owned corporation, however, is not convinced number three was solely responsible for the outage, though there is no evidence to suggest what else may have contributed to the loss of power, she said.

Yukon Electrical has said nothing on its monitors showed any problems with the distribution system that Monday, and it didn't have to make any repairs before power was fully restored.

With number three and four off line, Yukon Energy was forced to fire its diesel generators last week during peak demands at breakfast and supper.

As a result, the 22 consumers of secondary power - cheap power that is normally surplus hydroelectric energy and is often used for heat instead of the more expensive heating fuel - were taken off.

Patterson said Yukon Energy doesn't want to restore secondary power sales until number four, the largest of the territory's hydroelectric generators, is back on line.

The Whitehorse General Hospital, for instance, is a consumer of secondary power.

While the Minto mine and Pelly Crossing are not yet receiving power from the Whitehorse-Aishihik-Faro grid, they may be fully tied in by sometime next week, Patterson said.

It was expected the new customers would be on line by the end of September, though there have been, and still are, delays in receiving essential equipment.