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Letter to the editor

Field engineer's experiment triggered Florida blackout

The employee disabled system safeguards.

By Asjylyn Loder, Times Staff Writer
Published March 1, 2008

Florida's coast-to-coast blackout Tuesday might have been nothing worse than a fleeting electric twilight, affecting relatively few and quickly forgotten.

But one man tried to figure out what was broken and left roughly 2-million people from Miami to Jacksonville in the dark.

That lone field engineer working at Florida Power & Light's Flagami substation in western Miami-Dade County disabled a pair of safeguards that would have confined the outage to a few thousand customers, if any, explained FP&L president Armando Olivera on Friday afternoon.

The unnamed engineer, who had "significant tenure" at the utility, has been suspended with pay pending a full investigation, Olivera said. He declined to offer further details about the worker, except to say that he had not been injured in Tuesday's incident.

"I want to reiterate my apology to our customers and the communities we serve," Olivera said in a prepared statement. "We understand that this event caused a significant inconvenience."

How did one person trigger a blackout that affected 26 transmission lines, 38 substations and shut down at least nine power plants from Miami to Jacksonville?

He started out trying to diagnose a problem.

The substation has two levels of protection that keep disruptions in power -- called "faults" -- from damaging the system. A fault can be caused by something as small as a squirrel crossing a line.

Usually, one of the two levels of relay protection would "clear" the fault in less than a second, and customers would never know about the antics of the errant squirrel.

Workers sometimes disable one of the two protection relays to work on equipment, but they're prohibited from disabling both at the same time, Olivera said.

Still, Floridians might never have known about it if there hadn't been a fault at just that moment. In this case, the engineer caused it. About 1:08 p.m., he asked the control center to send a signal that would normally be disarmed in milliseconds by the relay.

Except, of course, that the relays weren't working.

Within seconds, nearby substations reacted, including one that ties into two nuclear reactors and a massive natural gas plant at Turkey Point, 25 miles south of Miami.

Power plants shut down in Tampa, Kissimmee, Jacksonville and Polk County, according to the Florida Reliability Coordinating Council.

According to the reliability council, about 930,000 electric customers lost power, including more than 200,000 in the Tampa Bay area. If households average 2.5 people, as Florida Power & Light estimates, that translates to more than 2-million people.

Asjylyn Loder can be reached at aloder@sptimes.com or (813) 225-3117.

[Last modified March 1, 2008, 00:25:24]