SCE Spells Out Approach to Power Outage Investigation

File photo. 

On Wednesday, Southern California Edison (SCE) issued a response to the California Public Utilities Commission (CPUC) which, in a letter sent earlier this month, had formally requested the company take specific actions related to Long Beach’s rash of recent power outages.

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S P O N S O R

SCE’s letter paints a cooperative portrait of the utility company, acknowledging each action requested of them and actions they have taken to address CPUC’s listed concerns, which amounted to seven separate demands. Yet, the company still has yet to identify an underlying issue or cause of the power outages.

“The safety of SCE customers and employees is our first priority,” read the letter, signed by Greg Ferree, vice president of the Distribution Business Line of Southern California Edison. “The company is continuing to cooperate with the Commission through its investigation into the outages and has already implemented some changes to the system to improve safety and reliability on the network.”

Since July, Long Beach has experienced six significant power outages, with the most recent outage occurring September 8. The cause behind the underground vault fires that resulted in widespread blackouts affecting over 30,000 people at their peak, has not yet been discovered or explained.

In their letter dated September 1, CPUC demanded that the following be done by September 30:

  • Detailed inspection of underground facilities and lead conductors and splices.
  • Detailed inspection on protective devices (such as relays, breakers, fuses and more).
  • Confirm ventilation system is properly working in all underground vaults that require ventilation systems.
  • Confirm transformers serving Long Beach are rated properly to meet customer demand, especially in times of peak demand.
  • Inspect and confirm reliable operation of the circuit supplying power to the Port of Long Beach and any spot serving a large number of customers.

SCE states that “thorough and detailed” inspections of 329 underground structures, including 303 underground vaults and other types of underground structures that compose the Long Beach Network System have been performed since the July 15 outage, including the requested inspections of lead conductors and splices. No major equipment problems were discovered, but the company did undertake a few minor repairs and system upgrades, some of which they are still in the process of implementing, according to the letter. Ongoing, routine detailed inspections of underground and overhead equipment (including manhole structures) will continue to be conducted, SCE stated.

Testing on circuit breakers will be completed within the year, according to SCE. Detailed inspections of protective equipment have occurred in the months following the initial July 15 power outage and additional tests on substation circuit breakers, relays and transformers continue. Follow-up corrective action will be prioritized, according to SCE.

An additional review of ventilation system installations has been called for, and will be completed for the approximately 2,100 additional underground structures throughout the City of Long Beach by the end of the year, with corrective action prioritized.

Actions have been taken to secure the 287 manhole cover lids throughout the city. Tethering alternatives are also being evaluated by SCE, according to the letter.

SCE is also testing a pilot project to analyze distribution transformer loading based on SCE’s metering data for the 14,000 distribution transformers in Long Beach, served from radial circuits, according to the letter. SCE stated that the 17 substations in Long Beave have also been evaluated.

In July, State Senator Ricardo Lara and assemblymembers Anthony Rendon and Patrick O’Donnell had called upon CPUC to demand a comprehensive review of the causes of the recent power outages, along with Mayor Robert Garcia. In August, SCE said they had hired a private consultant to conduct an investigation into the power outages, in addition to an existing internal investigation.

“The recent rash of outages, smoking vaults and explosion in Long Beach is very troubling,” CPUC’s September 1 letter stated. "The [Safety Enforcement Division of CPUC] believes that investigating and mitigating these unsafe conditions should be SCE’s top priority.”



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