One day after a Commonwealth Edison circuit breaker exploded at a key substation, producing a massive downtown blackout, Mayor Richard Daley on Monday called on ComEd to accelerate system improvements to prevent “what could be a disaster” in the future.
Daley said the utility must intensify efforts to limit broad collapses on its electrical grid when problems occur at single “choke points,” such as the Jefferson Street substation, site of Sunday’s breakdown.
As ComEd officials tentatively singled out a 5-foot long ceramic connector on the circuit breaker as a possible key to the breakdown, Illinois utilities regulators used the incident to highlight how ComEd’s ongoing improvements have yet to surmount basic flaws.
“Whatever the cause, an entire 9 square miles was depending on that one `well’ of power, and that remains the issue,” said David Farrell, spokesman for the Illinois Commerce Commission.
Though they stopped short of calling for ComEd to accelerate its $1.9 billion overhaul, ICC officials emphasized the urgency of the problem by citing a June report from a state-commissioned consultant that detailed maintenance delays and funding cuts at substations such as the one involved in Sunday’s power failure.
That report, issued in June by Pennsylvania-based Liberty Consulting Group found that “ComEd decreased substation maintenance expenditures from about $45 million in 1991 to about $15 million in 1998,” while circuit breaker and transformer failures at those sites continued at “excessive” rates.
Defending its improvement program, ComEd listed recent upgrades made at the Jefferson Street substation, including replacement of cables and rebuilding of 110 circuit breakers.
ICC officials said they have been satisfied with the utility’s progress so far. Consumer watchdogs said the blackout underscores the need for ComEd’s progress to be monitored.
“We’ve heard it all before–a piece of equipment failed and nobody can explain why it failed. … What we need is serious monitoring,” said Pat Clark, of the Citizens Utility Board.
Daley–calm and collected, in stark contrast to his angry, red-faced demeanor after a ComEd power failure downtown in 1999–described Sunday’s incident as “a rare occurrence.”
“The city will continue to closely monitor ComEd’s progress toward accomplishing this goal, but they must remain on course to alleviate the problems with these critical substations,” Daley said at a news conference, adding that the company has been very cooperative throughout.
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In fact, Sunday’s blackout would have been more widespread if ComEd had not begun upgrading substations after last year’s series of power failures, Chicago Environment Commissioner William Abolt said.
As part of its $1.9 billion program to improve infrastructure, ComEd upgraded the power lines coming into the LaSalle Street substation from 69,000 volts to 138,000 volts. That meant the LaSalle substation could get its power from the Taylor Street substation, rather than the overworked Jefferson station.
Had LaSalle still been connected to Jefferson as its only source of power, another 2,100 customers, mainly in the south and central areas of the Loop, would have been without power on Sunday, ComEd spokesman John Hatfield said.
Sunday’s equipment failure knocked out power from Chicago Avenue to 24th Street and Lake Michigan to Ashland Avenue.
Upgrading power lines to the substations will make them less dependent on “hubs” such as Jefferson Street, said Abolt and Pamela Strobel, ComEd executive vice president for transportation and distribution. That work is just beginning. Upgrades are scheduled to be in place in 2002, with nearly all of them completed by 2004.
But Abolt said Sunday’s incident underscores the need to speed up that schedule, if possible. ComEd officials said they will see if the timetable can be moved up.
“We are doing everything the engineers say is technically feasible to accelerate that timetable,” Strobel said.
If that isn’t possible, Abolt said, the company must build new redundancies into the system, even if they are temporary, to prevent more power failures.
The investigation of the failure now is centering on two porcelain “bushings,” 10-inch diameter connectors that link the circuit breaker to the power source.
The circuit breaker that exploded is made up of three tanks, each filled with 690 gallons of oil. There are two bushings per tank.
Nick Lizonich, vice president of engineering and planning for ComEd, said the explosion at 12:28 p.m. Sunday burst the metal top off one of the tanks and a manhole cover off the side. Bolts shot into other equipment, causing shorts, and oil from the tank ignited.
The problem would not have been found or fixed under the $1.9 billion plan because the equipment is relatively new, Strobel said. It was built in 1993 and installed in 1994.
Similar devices “are in common use throughout the country” and there is “no known history of failure,” Strobel said. Even so, Daley said the company must check for defects in about 30 similar breakers throughout the city.
ComEd said it was too early to know what led to the explosion.
ICC officials said the June report highlighted maintenance and staffing lapses at substations over the past decade. “The ComEd substation maintenance programs lacked sufficient budgeting, supervision or manpower to complete maintenance on a timely basis,” the consultant wrote.
A report specifically about the high-voltage transmission system is to be released next week.
ComEd will reimburse the city for police, fire and other costs, merchants will not be paid for lost business.
“That is a harsh answer, not something … that goes down well, but there is no utility in the country that takes on that kind of responsibility,” Strobel said.