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 Post subject: Can we discuss this video?
PostPosted: Tue Sep 23, 2008 5:29 pm 
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Location: New England
http://www.youtube.com/watch?v=0vvkhpT7QQI

This was posted on this forum and was found on youtube. Its hard to tell exactly what is happening but can we speculate.

Does anyone know where this occurred?

It looks like 480V gear to me, what do you think.

The electrician is turning the crank clockwise, so I would guess he is racking in a draw out breaker.

Notice that he puts his ear muffs on just before he starts racking. He was just talking to his buddy, and it is an MCC room so it is probably quiet. So did he put his ear protection on as part of arc flash.

He has long sleeve shirt and pants look like uniform. Could he be dressed in FR clothing.

Can you tell if he is wearing eye protection or gloves.

Any idea of bad the injury was or what caused the fault.

Lesson, always meg the phase to phase and phase to ground to make sure there is no inherent faults before racking in breakers. Even a fluke ohm meter would have prevented this.


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PostPosted: Wed Sep 24, 2008 5:30 am 
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Location: Charlotte, NC
haze10 wrote:

Lesson, always meg the phase to phase and phase to ground to make sure there is no inherent faults before racking in breakers. Even a fluke ohm meter would have prevented this.


True statement, but other things can go wrong when racking breakers that a megger test would not revealed. He seems to be racking it in, out, in, having problems obviously, could be the primary disconnects were misaligned and snapped off, causing the flash, experience and knowing what this feels like is a must. Of course I am speculating on this senario also, my point is, other things can go wrong.

This video has been discussed here and in other forums, seems this happened in the UK, I dont recognize this as any gear common in the US but agree it looks like a 480V main or Tie.

Just another reason many companies or going to remote racking systems.


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PostPosted: Wed Sep 24, 2008 7:36 am 
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Location: NY
Arc flash Video

This is the same one posted on Live Leak . On live leak one of the comments stated that a PM was being performed on the breaker but was not complete when they inadvertantly racked it in . On the floor near the sceen is , what looks like a meggar . Checking for a Phase to phase or a phase to frame problem should be mandatory, before restoration, anytime after a breaker is PM'd or transported. It would have prevented this.
Also, tagout and work permit issues here . This error chain had quite a few links . Up to and including improper PPE.


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PostPosted: Wed Sep 24, 2008 5:37 pm 
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Sorry but I don't see the 'in and out'. It liooks like a steady clockwise stroke, little stronger on the downstroke than the upstroke, but don't see him changing direction.

I can't say that I ever tried to rack in a breaker that was in the closed position. I got a feeling it can't be done even if you wanted to as there is probably some cam or lever that would lockout or open the breaker. If it was a closed breaker, and he racked into a bus with ground straps still on, that would explain it.

ONe other point of advise I can give when racking. I've noticed that that line and load jaws can often be installed in different orientation - jaw open top/bottom or left/right, or one jaw is opposite the other. So if I have any breaker work being done, I always look into the cubical to verify off the bus how the jaws should engage. If the jaws are out of alignment, you could still make contact with the racking mechanism forcing distortion in the jaws and not engaging, but making contact, and then when you close to the load you get a blow out arc. (PS. I never did this but learned from a person who knew more than me).


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PostPosted: Thu Sep 25, 2008 7:15 am 
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haze10 wrote:
I can't say that I ever tried to rack in a breaker that was in the closed position. I got a feeling it can't be done even if you wanted to as there is probably some cam or lever that would lockout or open the breaker. If it was a closed breaker, and he racked into a bus with ground straps still on, that would explain it.

I have, but only while inspecting switchgear before shipment to make sure that it can't be done. If they are built according to industry standards, breakers can't be racked in while closed.


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PostPosted: Thu Sep 25, 2008 11:21 am 
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haze10 wrote:
I can't say that I ever tried to rack in a breaker that was in the closed position. I got a feeling it can't be done even if you wanted to as there is probably some cam or lever that would lockout or open the breaker.


We've had the that lever break on one of our breakers. The breaker got racked in while in the closed position and blew the doors off the switchgear. Luckily is was being racked remotedly! It still managed to blow the windows out of the door to the room and caught a stray custodian's cart on fire. (The custodian wasn't there.)


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PostPosted: Thu Sep 25, 2008 1:18 pm 
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haze10 wrote:
Sorry but I don't see the 'in and out'. It liooks like a steady clockwise stroke, little stronger on the downstroke than the upstroke, but don't see him changing direction.

.


Thats because that link was to a cut down version of the video, the full video is over 2 minutes long and shows much more of the story


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PostPosted: Thu Oct 30, 2008 6:58 am 
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I recieved some new info today on this video. Turns out this took place in Bogota Columbia in April 2007. The breaker being racked in had been in storage for a long time in a damp location allowing the fiberglass insulation to absorb moisture. The breaker is being placed back in service and racked in for the first time, no one tested the breaker before installation, when the line side disconnects contacted the buss the damp insulation allowed a phase to phase fault to occur.


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PostPosted: Mon Nov 17, 2008 9:39 am 
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Was that really 480V gear? Appears like it could be 5kV though that probably is a moot point.


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