CLALLAM BAY — A tree that fell into a Clallam County Public Utility District power line Thursday afternoon sent five times the normal amount of power through homes in the Clallam Bay-Sekiu area.
The surge knocked out power to more than 1,500 customers for several hours and destroyed numerous electronic equipment and appliances.
It also destroyed the utility district’s lightning arresters designed to handle 10,000 volts.
“It caused a fire at Slip Point, a neighbor’s dishwasher was set on fire, another’s stove was destroyed,” said Dave Weir from Al’s Mini Mart in Clallam Bay.
“I lost my VCR, two DVD players, a coffee pot and a microwave oven.”
Utility district chief engineer Dave Proebstel said the district’s transmission line runs along the south side of state Highway 112.
A large cottonwood tree on the hillside next to the highway fell into the district’s transmission and distribution lines, he said.
Because it created a transmission short circuit, Bonneville Power Administration’s circuit breaker at Sappho opened, Proebstel said.
But before that happened, a transmission conductor made contact with a distribution conductor, causing the power surge, he said.
Line carries 69,000 volts
The transmission line carries 69,000 volts and transmits 39,000 volts to the ground, so a house wouldn’t have received more than the latter number, Proebstel said.
The power also would have traveled through a “stepped-down transformer” that controls how much power a house receives, he said.
So a house might have received five times the power it normally gets, as much as 600 or 1,200 volts instead of 120 or 240 volts, Proebstel said.
