A fire at Rocky Mountain Power’s Rigby Substation Wednesday was the result of a failure of a voltage monitoring device.
The device is designed to protect company and customer electronics, said spokesman Dave Eskelsen. When the device failed, it triggered other safety mechanisms to open all circuits and shut down the substation for safety.
The substation serves upper valley customers and the area north and west of Idaho Falls, Idaho.
Technicians restored the Rigby substation and it came back online Thursday morning, bypassing the failed equipment.
Rocky Mountain Power technicians said the cause of a fire at its Rigby substation Wednesday night is still uncertain.
Spokesman Dave Eskelsen in Salt Lake City said as soon as the outage began at around 10:20 p.m. crews began working to restore power to around 27,000 customers from other directions.
Most were restored, in stages, by midnight with another large group of customers coming back on line at 3:30 a.m. Thursday.
Around 800 customers in the Lewisville and Rigby area, served by a Menan substation, ended up restored in stages at 6:59 a.m. and 7:36 a.m. Eskelsen said it appeared that outage was a separate problem that had to be repaired by a lineman.
Rocky Mountain Power crews were expected to be working Thursday on restoring normal operations to the Rigby substation. Eskelsen said that work should not interrupt power to customers.