LADWP gives briefing on Labor Day weekend outage

During Wednesday’s Bel-Air/Beverly Crest Emergency Preparedness meeting on Wednesday, September 16, 2020, LADWP representatives gave a briefing on why power was out in some Bel-Air areas for over 30 hours.  Here are some quick, raw notes from that meeting with LADWP’s Deborah Hong, Walter Rodriguez and Juan Esparza:

• Labor Day weekend, Los Angeles experienced record heat temperatures — 121 degrees,  This heat caused stress on the transformers.  This recent heat event resulted in evening temperatures of 70 to 80 degrees, when transformers usually cool off enough to be able to handle the next day’s power demand, These evening temperatures were not adequate for the cool down for transformers.

• Prior to this heat event, LADWP had been replacing transformers around the city that showed signs of imminent failure.  They had replace 300 of them prior to the recent heat event.

• A transformer usually services 25-30 customers and an outage due to transformer failure is called a “small neighborhood outage.”

• To replace a transformer it can take 4-12 hours but in some cases repair is longer.  Sometimes the transformer is difficult to access because it’s on a rear property line and crew cannot easily get equipment in position — so crews must hand carry equipment and rigging.

• To replace a transformer located underground,  those vaults are difficult to maneuver inside of as they are crowded and small.

Other issues:

• COVID-19 has more people working and attending school from home that results in extra demand for power that added stress on the transformers.

• COVID-19 restrictions on LADWP crews as they must wear masks, creating a longer time to work as they physically do not overheat and become safety issues themselves.

• LADWP had prearranged crews to work throughout the Labor Day weekend’s heat event (100 crews).

Events of Labor Day weekend power outage:

• Outage that happened on September 3rd affected 1300 customers and was caused by one of the main power feeders in an underground vault.  Unlike an overhead transformer repair, a failure in an underground vault is a difficult repair process with time-consuming isolation methods to locate the problem.  It was discovered that over 900 feet of cable went bad inside a duct.  Evidently, over the years, the cables in the duct had been compromised (such as water intrusion and the expansion and contraction causing insulation breakdown between the conductors).

• It took over 24 hours to locate the problem, pull the cable, splice the cable and replace it into the duct and re-energize it.

• There was also another issue in Laurel Canyon where a tree had fallen and that took time for crews to repair.

• With temperature at 121 degrees, the stress on transformers resulted for the first time since the Northridge Earthquake, a “Level 3” response time.

LADWP’s Levels of response times:

Level 1 - 4-12 hours response time;

Level 2 - 12-24 hours response time; and

Level 3 - Days to respond - service is overwhelmed - (“complex storm” or “earthquake”) - The Department has experienced a major disaster, usually an earthquake with a magnitude of 6 or greater, and with an epicenter located within a 25-mile radius from City Hall, or a complex storm or series of storms may have occurred. It is assumed that an earthquake of this magnitude or within the city limits or a complex storm would cause severe damage to the Department’s electrical system however an earthquake of lesser magnitude may cause significant damage also. Electrical substations (Receiving and Distribution) may sustain facility and/or equipment damage requiring it to be repaired or replaced before being placed back in service to carry load. Customer calls meeting the Customer Service Guarantees criteria may not be responded to for one or more days. Callers are advised that we have sustained major damage to our electrical system, ALL available personnel are in the process of “rebuilding” the electrical system, and we may not be able to respond for days, provided we don’t sustain further damage from after shocks. DWP does not have any portable generators.