KUA Substation Fire

[safetman1]

KISSIMMEE --
A worker was killed Sunday morning when part of a Kissimmee Utility Authority power substation exploded.

The incident was in the area of 1100 Davis Street in Kissimmee.

KUA officials say two employees and a contractor were performing maintenance on a 69,000 volt transformer at a control house when the explosion happened. The contractor, a woman, died. Her name has not been released. The two employees, Robert Treasure and John Johnson, were airlifted to Orlando Regional Medical Center with second and third degree burns.

"I woke up to a large boom. Everything in my house was shaking," said Emerald Ford, who lives nearby.

Ford stepped outside her home to see the substation across the street going up in flames, and a the workers trying to running away. One of them was on fire.

"[People tried to help her out, but couldn't do anything?] They couldn't help her out. She fell to the ground. She didn't move anymore," said Emerald Ford.

Officials temporarily closed parts of Pershing Street and South Hoagland Boulevard.

Thick black smoke could be seen for miles in the area.

"I saw it from all the way in Holopaw and I was on my way to do some work here in the area," said one neighbor.

The contractor, an employee of Reinhausen, was pronounced dead at the scene by Osceola County emergency officials.

“Our thoughts and prayers are with the families right now,” said Jim Welsh, KUA’s president and general manager. “This is a tragic event and a difficult time for all of us.”

"It's something that I'll never forget," Ford said. "I'll never be able to get those images out of my mind. All I can think about is I hope she didn't suffer."

The transformer was a new piece of equipment, having only been in service a few months at the substation.

The accident is under investigation.

[topgroove]

The transformer was only in service for a few months.... I doubt we'll ever find out what maintence work was being done on the energized piece of equipment. I wonder if the secondary bus tie was closed ?

Witnesses recount horrifying explosion at Kissimmee power substation

[HIVOLTS]

Reinhausen specializes in load tap changers. Maybe that's where it started. They are nothing but trouble. Our company decided at the begining not to have LTCs. We regulate every feeder.

[topgroove]

Ya know, HIVOLTS.... that would make sence. I hate speculating on things like this without knowing the facts. I'm gonna guess this was a 230KV to 69KV transformer with a built in tap changer. We know it was only in service for a couple months. I'm guessing the women who died was a service tech for the manufacturer of the transformer. Is it possible something went terribly wrong internally when they tried to manually change tap settings?

[lewy]

All of our station transformers have automatic tap changers, that our system operators can put on manual when switching and we have had no problems with them.

[topgroove]

I here that Lewy, same here. Obviously something went very very wrong here. We're just trying to piece together the clues. All we know so far is this was a fairly new piece of equipment. The women who died was what I assume was a service tech for the manufacturer. Something must have been adnormal with the transformer for her to travel on site. Something caused that transformer to go super nova. I fairly sure it didn't simply explode without some sort of action on the part of the service tech. Could it be the tap changer was not opperating properly and she was there to try and trouble shoot the problem?

[Divemaster]

Like topgroove said, we need to piece things together. It's hard to tell in the pic, but to me, this looks like a larger sub with maybe two or more transformers in it. If they went and tied two substation transformers together and that close together they would have had to have the secondary voltages as close together as possible approximately 0.7 volts on the test point in the LTC cabinet. I have yet to work on the inside of a Reinhausen and don't know exactly how they operate but if they are anything like an AC or Siemens there is the possiblity that the taps were askew inside even if the voltages matched since your test points are only on one phase. The difference of potential on one phase could cause catastrophic events to occur.

[ghostdance56]

Word on the street is that this Siemens unit was made in Columbia. When it was first delivered, it was defective and sent back to Columbia. It came back not much different than when it left. Two other Reinhausen personnel had previously been to Florida to work on the problem; part of which was the noise it was making while changing tap. When Beverly was working on it, the transformer was not tied in on the secondary side only the high side. Hence no customers lost power as reported. Reportedly, the LTC door blew open throwing Beverly 30-40 feet back and soaking her in oil which ignited. She never had a chance.

[topgroove]

Thanks Ghost.... that certainly clears things up. I'm not a substation guy but I would think the tap changer should have been able to have been taken off line compleatly and ran up and down?

The strange noise it was making while changing tap may have been a warning sign that something mechanical inside the tank was mis-aligned , loose or missing?

seams typical don't it! Once a piece of equipment has been shipped installed and set-up all of the sudden support goes away. I wonder if that poor women knew the whole story behind that tap changer?

[Divemaster]

In my experience with the 7 LTCs we have, it should sound smooth and snap firmly when operated. That and every time I've helped work on our LTCs, we've had the transformer de-energized since the LTC control and motor only needed 120 volt station power that was provided from a separate transformer. Usually though, we've also had the oil drained and the LTC cabinet open to actually see what is going on inside. After any repairs, we will run it up and down several times like this to make sure everything is operating properly and does sound right. Then we'll closeup the unit to put back in service, go through the same motions only with oil in it then finally energize the tub and do the same while checking the voltage on each step. I truely do feel sorry for this gal and her family. It does make me think though about two units that we have, on one the LTC is right next to the control cabinet, the other it's above. This is definately going to be one of our safety meeting subjects and one I'll use when training our switchmen.