Found THIS very interesting video of a 480 volt arc blast test.

Despite the somewhat unusual test conditions (a solid bolted fault directly on a transformer's terminals, the timed cutoff of the power {you'll hear a "ding" like a microwave saying dinners done}) it would be not too far off from the potential forces in most switchgear, I'd imagine.

Watch this and think about what would have happened if you were standing near that transformer.

The electric dragon spares no one when he decides to breathe fire.....

Please be safe!!!


Edited a few times to fix link...


[This message has been edited by mxslick (edited 08-16-2006).]

[This message has been edited by mxslick (edited 08-22-2006).]

[This message has been edited by mxslick (edited 08-22-2006).]

Thanks for that video clip.

It's amazing how much energy is available, especially at the transformer terminals.

Low resistance connections, maximum fault level available, high PSI and good quality switchgear.

Most good quality BSS HRC fuses are rated to break safely a fault at 80 or 120 kA.

You can see that good quality switchgear and HRC fuses are a must to clear low resistance faults near distribution transformers especially when cable runs are short and are of heavy gauge cable.

Is your email correct RODALCO? I have a question for you, if you don't mind.

Thanks,
Dave
dave@tigerelectrical.com

Thanks Tony. That gets the point across much better than words.

Roger

I can't see it. All I get is:

Forbidden
Remote Host: [my IP address]

You do not have permission to access http://electricsubstationsafety.com/Movies/Test%2024.mpeg

Data files must be stored on the same site they are linked from.

Thank you for using FreeServers

Added: never mind, I got to the directory by lopping off the last part of the URL.

[This message has been edited by Larry Fine (edited 08-16-2006).]

Larry, I get the same message.....

Just go here:
http://electricsubstationsafety.com/photo5.html

and click on the appropriate link.

Somehow, a "%20" code got inserted into the posted link in place of a space.

Heh, I'd posted that very video in the safety forum about 2 weeks ago!

More videos here: http://electricsubstationsafety.com/photo5.html

Steve:

No wonder!! I was at a loss as to where I first ran into that video, I honestly had thought it was on one of the other sites I browse...major brain flatulence here!!

That's what I get for posting when I'm tired!!

So a big thanks to SteveFehr for bringing that link to my (stunted) attention!!

That arc-blast video is shocking at the least! And I don't mean electric shock!

At the end of the first (transformer failure) video, you can just barely hear someone start saying "We need all available en-gines..."


Ian A.

[This message has been edited by Theelectrikid (edited 08-21-2006).]

As a note to that particular video, it was explained that the substation protection scheme had failed, due to a defective $5.00 fuseholder!! The fuseholder in question was a panel-mounted, "AGC" type.

The initial fault was believed to be a failed capacitor, and when the protection system didn't detect it, it evolved into the runaway arc welder in the video.

The transformer's oil began boiling, and about halfway through the clip you can see it venting from the overpressure valve and transformer's top. The oil then ignited into the fireball.

The flash and bang is the expulsion fuse on the transformer's primary finally blowing, killing the power.

The substation was a total loss.

I've heard different ideas as to the origin of the video, one of which said that this all took place near a fire station, another that it was behind a golf course, and another that it was behind a residential development. But it seems to be agreed that it was in the Miami/Dade area of Florida.

Anyone from that area able to confirm/provide more info?

Here's another, related video of power line faults during a storm....

HERE

Note the faults that occur to the right of the image near the end....my guess is that was a transformer letting go from the stresses of the arc faults. (You'll see orange glow, as opposed to the blue of the arcs.)

Cool shots !