Hawaii Electric Light Co. is trying to determine what’s causing an East Hawaii transmission line to fail.
The line, linking substations in Kaumana and Pohoiki, has shut down four times since March 10, said Roger Keller, HELCO distribution manager.
The most recent outage affected 5,309 customers in the Puna and Waiakea areas for less than a minute Monday.
One outage on March 13 also blocked power to a separate transmission line, causing Puna Geothermal Venture to automatically shutdown.
About 20,000 customers lost power during that incident. Other recent outages have affected about 9,500 customers.
“We’re very concerned about it,” Keller said.
“Our customers need to know they are going to get secure power.”
Keller said the utility has conducted helicopter flyovers to try pinpoint what’s causing the problematic line to fail. Infrared cameras have also been used.
But the problem could be located in a heavily-wooded area. HELCO crews are currently building an access road to check the line pole by pole.
“We are bulldozing in there again today,” Keller said Tuesday. “We’re hoping to finish up the access road by the end of today so our trucks can go in.”