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#42497 - 09/21/04 10:52 PM wow watch this  
dougwells  Offline

Joined: May 2003
Posts: 1,137
kamloops BC Canada
Not sure what to say

This was a quote that came along with the link i recieved not sure when this happened unless someone could photoshop this

" There was reportedly a problem shutting down a 500,000 volt electric utility circuit by conventional means, so the circuit was opened at the Palo Verde switchyard while under FULL load, with spectacular results. (This may be the Palo Verde Nuclear

[This message has been edited by dougwells (edited 09-22-2004).]

Work Gear for Electricians and the Trades

#42498 - 09/22/04 12:13 AM Re: wow watch this  
hbiss  Offline
Joined: Dec 2003
Posts: 886
Hawthorne, NY USA
Somebody posted a link to a longer version of that awhile back.


#42499 - 09/22/04 12:27 AM Re: wow watch this  
dougwells  Offline

Joined: May 2003
Posts: 1,137
kamloops BC Canada
ah guess i missed that somehow

#42500 - 09/22/04 09:22 AM Re: wow watch this  
Crowbar  Offline
Joined: Jan 2003
Posts: 33
Pittsburgh, PA,USA
Is it just me, or did I only see one phase of that switch arc?

#42501 - 09/22/04 10:55 AM Re: wow watch this  
dougwells  Offline

Joined: May 2003
Posts: 1,137
kamloops BC Canada
Yes. I asked an acquaintance from Manitoba hydro about it. this is what he wrote.

My dept. has had numerous discussions about this very same video.
They are using a device called a circuit switcher - it consists of an air-break mechanism and vacuum chamber (vac-rupter) that is used to break/extinguish the arc under load. If I recall correctly, this cct. switcher had it's vacuum chambers fail and lose vacuum, thus severely de-rating it's interrupting capacity, they called on it to operate and break load - which it didn't really succeed in doing.

If you notice in the video, a bit closer to the camera is the 500 kv O/H buswork, if there had been a wind (or a different wind direction, for that matter), the arc would certainly have drifted into the buswork (or into the other 2 un-failed phases of the circuit switcher) and caused a 3 phase flash over with no means at all to extinguish the arc, other than the over current relays acting on the fault that would ensue when the whole structure fell, or possibly the harmonic units sensing some really ugly stuff and tripping the line via an upstream breaker.
I happen to have a sister unit to the very same circuit switcher in the video installed in one of our export stations, we use it to switch a 200 MVAR reactor bank for power factor correction, the other end of the export line I'm talking of, has the same cct switcher as well, but they use it to do the opposite - they switch in/out a 200 MVAR capacitor bank.

#42502 - 09/22/04 12:02 PM Re: wow watch this  
Trumpy  Offline

Joined: Jul 2002
Posts: 8,211
SI,New Zealand
Hey Doug,
How come I can't get the link to play?.
It loads WMP, but it says that the duration of the file is 00:00?. [Linked Image]

Let's face it, these days if you're not young, you're old - Red Green grin

#42503 - 09/22/04 12:11 PM Re: wow watch this  
dougwells  Offline

Joined: May 2003
Posts: 1,137
kamloops BC Canada
Hi Trumpy

It played in Winamp for me

#42504 - 09/22/04 12:21 PM Re: wow watch this  
mamills  Offline
Joined: Nov 2001
Posts: 745
Wharton, Texas, USA
What happened that finally caused the arc to be extinguished?

Mike (mamills)

#42505 - 09/22/04 12:40 PM Re: wow watch this  
dougwells  Offline

Joined: May 2003
Posts: 1,137
kamloops BC Canada
Mike I am not really sure I just seen it on a forum and thought i would post it here

#42506 - 09/22/04 01:49 PM Re: wow watch this  
mustangelectric  Offline
Joined: Feb 2004
Posts: 494
Bentonville, AR
the arc could not sustain itself uder those circumstances. had the arc blast switch worked it would have extingushed or broken the arc long enough (milli seconds)and you would not have seen near the arc..

its a good thing they were clear of that line!

to view the file, try right click>save target as and save to your computer...then get your video player will work..



Electricity has no respect for ignorance!

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