Archive for Thursday, December 6, 2007

Black start’ necessary in case of KCPL outages

December 6, 2007

A "black start," such as the one city crews pulled off during Saturday's power outage, is just that -- starting in the black.

When Rob Culley, power plant operator, arrived at the plant Saturday at 8:35 p.m. it was just like most of Baldwin City -- dark. The lights were out, except for the emergency lights strategically placed in the building.

Culley called KCPL, the city's power supplier most of the time, when he arrived. He didn't get an answer on how long the outage would last and started the "black start" procedure. When his second call to KCPL didn't result in a better answer, the start was on.

It involves cranking up an emergency generator housed at the plant. The diesel-driven engine that packs a 200 kilowatt punch is used to start the two 4,200 horsepower engines that provide Baldwin City its power during summer's peak usage times and other emergencies.

"You cannot start those engines without power," said Culley.

Although engines are "dual-fuel" engines which can be run on diesel fuel or natural gas, they have to have electricity to start. The emergency generator fills that bill and more.

"It's plenty big enough to run this facility and the water pumps," said Culley.

The procedure is well known and practiced.

"We do 'black start' simulations all the time," he said. "We just did a 'black start' simulation a week ago."

Once the emergency generator, which is mobile and can be taken to the city's water pumps if necessary, is running, the process doesn't take long.

"By the time I start it, unlock the office and switch the breaker, it's ready to go," said Culley.

Because it's the winter down time, part of the procedure also includes opening the lines to the cooling towers that provide water to the big engines. After that was done, it was time to crank the engines.

"We start one and get it online and it goes off 'black start,'" he said, adding it's not long after that when the engines are producing power. "In a situation like Saturday, we start them up right away. They warm themselves up pretty quickly."

But, the city can't all be brought online at once. There's a process there, too.

"By then, you're able to generate power," said Culley. "We've already opened the breakers at the Newton Substation. At that point, everything is up and running.

"We take the feeders one at a time," he said. "The nursing home is first. Once it's up, we'll bring the other units up. The downtown and Baker University are next. They are smaller loads before we add the northeast and northwest feeds which are our largest two feeders."

On Saturday, that whole process began at 8:45 p.m. and was completed by 9:17 p.m. It isn't instantaneous, but it's not that slow.

"That's about as fast as we can do it," said Culley.

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