TORRANCE, Calif. (KABC) --A wiring error during an equipment upgrade caused a power outage that affected nearly 100,000 customers and shut down a refinery in Torrance, Southern California Edison said.
The error occurred Tuesday morning at the Torrance electrical substation. Edison has been working for the past four years to increase the capacity of the substation by adding a large power transformer and upgrading circuit-breakers and automated systems.
That included temporarily re-wiring a device that trips a circuit-breaker when it detects an electrical surge or fault, said Paul Grigaux, Edison's vice president of transmission, substations and operations.
On Tuesday, electrical demand rose after a long Columbus Day weekend. Because upgrade work had isolated a section of the substation, the load was shifted to another section where, due to the wiring error, "it gave this protective device the impression that it was a fault... and tripped a circuit-breaker," Grigaux said.
The massive outage left more than 90,000 Southern California Edison customers in the dark and caused flaring at the plant for the third time in about a month.
"If there's windstorms and rainstorms, you could almost explain it away. But here, we have almost perfect weather - but maybe that perfect weather, the sun deteriorates their lines," said Torrance Mayor Patrick Furey. "So it's ongoing maintenance, obviously, the rates that they charge, all of that comes into play."
Furey met with Edison reps, hoping to find solutions. The utility company has vowed to improve.
"We're hopeful that they'll get a dedicated line into the PBF refinery, which I think that would release some of the pressure on the rest of the grid to our residential customers," Furey said.
Now, there are some concerns about the opt-in Torrance alerts system.
Torrance resident and clean energy advocate Michelle Kinneman is signed up for both text and voicemail alerts but was already on her way to work Tuesday when the first "shelter in place" text came in - an hour after the flare-up.
"I ended pulling off to the road, checking that message, and heading back home realizing that I didn't want my daughter to have to walk to school if indeed we were supposed to be sheltering in place," Kinneman said.
She said in addition to timely and accurate alerts, she's fighting for what she calls the bigger picture.
"We need to move rapidly to a point where we're not relying on the Torrance refinery or any other refineries to power our lives," Kinneman said.
Furey said improvements on the alert system were underway, adding that in the year or so that it has been up and running, only about 13,000 subscribers have opted in.
The Associated Press contributed to this report.