Electrical vault explosions that left thousands in Long Beach without power for several days this summer stemmed from a cascade of breakdowns that originated in Southern California Edison’s mismanagement, according to two reports released Tuesday by the company.
The vault explosions and outages were set in motion by the failure of a single cable splice -- the point at which two pieces of cable are joined -- according to the company’s internal report, which reached the same conclusions as the external inquiry completed by a consulting firm.
But the malfunction of one cable splice usually doesn’t trigger what Long Beach saw starting July 15, the reports said. Nearly 30,000 customers lost power at the peak of the outages, which lasted up to five days -- three underground vaults were ignited and circuits were automatically shut off.
The investigations found systemic causes including poor oversight and inadequate knowledge about the network, according to Edison’s report.
Some equipment was improperly installed, and some employees were unaware of specific steps to ensure equipment was properly functioning, the report said. In addition, the network’s maps were not “consistently updated” and often inaccurate.
“We are deeply disappointed that the findings point to shortcomings in SCE’s operation of the network,” Pete Dietrich, Edison senior vice president for transmission and distribution, said in a statement.
The reports concluded that the second series of outages, which began July 30 and continued through Aug. 3, were caused by a cable that was overwhelmed during the July 15 outages.
Edison shared the findings of the two investigations with city officials and the state Public Utilities Commission, which is currently conducting its own probe into what led up to the outages. Mayor Robert Garcia asked for the CPUC inquiry.
The outage was the worst the company’s Long Beach customers have endured in at least 60 years, the company said.
Part of the challenge for Edison was that the area affected by the outage has a unique electrical design, according to Edison officials.
The grid is powered by a loop of electrical lines with no central beginning and end, said Paul Grigaux, vice president of transmission substations and operations for Edison.
Since the outage, Edison has paid $1.8 million for thousands of claims by residents and businesses, Edison spokesman David Song told the Long Beach Press-Telegram. The city is also claiming damages of $435,000 from the outages, according to a claim filed in October, the newspaper reported.
The company has taken steps to prevent outages from wreaking havoc on the electrical grid. The reforms include a thorough investigation of every underground vault in downtown, more employee training and additional inspections on the rest of the grid.
Assemblyman Anthony Rendon (D-Lakewood), chairman of the Assembly’s Committee on Utilities and Commerce, said he was “disappointed” by Edison’s performance, and he called on utility companies across the state to prioritize safety and reliability.
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