Faulty Wires Caused Huge Blackout, DWP Claims

The 5 1/2-hour power failure in West Los Angeles and part of the San Fernando Valley Tuesday night was caused by a malfunction in the wiring that controls a power station’s circuit breakers, officials of the Department of Water and Power said Wednesday.

The malfunction tripped the breakers and interrupted the flow of electricity to 18 smaller distribution plants, the officials said.

Reacting to the blackout, the Los Angeles City Council ordered a full report on the incident after Councilmen Marvin Braude and Zev Yaroslavsky blamed DWP officials for not anticipating the problem.

A DWP official, addressing the City Council, replied that there was no way to foresee the malfunction.

The outage cut off power to 105,000 DWP customers, shut down UCLA for a time and snarled rush-hour traffic from the northern rim of the Santa Monica Mountains near Mulholland Drive in the north to Venice in the south.

Dozens of people were trapped in stalled elevators in high-rise buildings throughout the area, but no life-threatening situations occurred, police said.

Rare Occurrence

The malfunction caused the automated, unmanned power plant at 1840 Centinela Ave. to shut down about 3:15 p.m., cutting off the flow of electricity to the 18 smaller plants, said Norman Nichols, assistant DWP general manager.

The internal wiring problem caused an uncommon situation: the shutdown of an entire power station, Nichols said.

Plants of similar size have been shut down in the past because other power suppliers, such as Southern California Edison Co., suffered outages, he said. It is rare that one like the Centinela station--with a capacity of 400,000 kilovolt amperes--shuts down because of internal problems, he said.

“We have had transformer failures, partial failures within those kinds of stations on a very infrequent basis,” said Nichols, who has been with the DWP for nearly 28 years. “I cannot recall ever losing an entire station.”

DWP officials said they do not know why the wiring system went awry. Batteries connected to the system in the event of an outage also were rendered useless when the breakers opened.

After the trouble was reported Tuesday afternoon, it took DWP employees about 45 minutes to got to the unmanned station, Nichols said. They assessed the situation, and repair crews were then called in, he said.

By 5 p.m., the DWP began “field switching,” bypassing the damaged wiring to transfer power to the 18 smaller plants, Nichols said.

Power was gradually restored to the affected areas by 8 p.m. All of the blacked-out neighborhoods had full power an hour later, he said.

Repair crews pulled the suspected faulty wiring out of service Wednesday morning and routed power through other circuits in the station, putting it back into full operation.

Robert Shepard, an assistant engineer for operations and maintenance, said the wiring in question will not be replaced until the source of the problem can be pinpointed.

Nichols’ explanations, however, did not sit well with the City Council when he appeared before it.

Calling the failure a “major catastrophe,” Braude, whose 11th District was hit hard by the blackout, said DWP officials should have anticipated the possibility of an automated, unmanned station shutting down.

‘That’s Not Enough’

“It’s not enough for me to say that there are technical difficulties that you don’t know and can’t figure out,” Braude said. “That’s not enough. We pay our managers well, and we expect good managers . . . to anticipate technological problems.”

Yaroslavsky criticized the length of time it took DWP officials to restore power after identifying the problem. Nichols responded that a helicopter was standing by to rush repair crews to the station but that foggy conditions in West Los Angeles caused the crews to drive there instead, in heavy rush-hour traffic.