Power line videos. Neat stuff

Confetti causes a flash over between power line conductors. I wonder why it travels horizontally like that?
http://www.youtube.com/watch?v
XAonbevaA
I thought this one was pretty neat. A linesman servicing HV lines from a chopper.
http://www.youtube.com/watch?v=HcalasGr_uk&mode=related&search

--
Thank You,
John Riegle
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Do a search on Jacobs Ladder Arcs.
--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
writes:

Heat seems to pull the arc up, but this is horizontal and judging by the sparks there is little or no wind. John
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Hello All

I have not seen the video, but if you have a pair of parallel wires, and establish an arc between them it will travel along the wires away from the power source. Remembering that the arc could be replaced by a piece of wire, if you work out the force on the piece of wire, by doing the appropriate integrations on the fundamental equation Force = Flux Density x Current x Length you will find that with a few thousand amperes of current there is a significant force in this direction.
There is a message in this for those investigating equipment failures. That is that the major damage will be where the arc ends up. The place where the failure started is usually somewhere back towards the supply from this point. You can usually find a series of bright spots on the conductor where the arc was stationary for a few milliseconds.
If you consider single phase ac supplies the arc will often go out for a short time at current zero and then restrike.
John
--
John Rye
Hadleigh IPSWICH England
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Pretty silly. Arcs find least resistance paths, period. Air ionizes around them, and some lines are coated, so an arc could move in either direction.
These were parallel lines, so it likely moved along them as it breeched the coating on them, blazing a trail as it were.

Any arc that remains stationary is going to heat up the start and finish points (which each is both for AC) heavily at the location where it stands in one place.

Since all three phases are not carried on ONE pair of lines, the same occurs one a three phase system where the arc is typically only on one of the phases.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Hello
wrote:

Agreed that arcs normally find the least resistance path.
Agreed that if the conductors are insulated it will slow the movemant down.
But you are forgeting the magnetic forces. The arc will move away from the power source, and I have plenty of videos from experiments demonstrating this. Unfortunately they are on film, and can not therefore easily be put on the web.

Sorry but no. The arc will run on all 3 phases. If you look at a high speed film you can see the current zeros occuring on each phase, but except for these very short breaks, on a three conductor arrangement with bare conductors there will be arcs on all three conductors.
John
--
John Rye
Hadleigh IPSWICH England
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
----------------------------
writes:

--------------- Actually the most common arcing fault on a 3 phase system is line to ground on one phase. However, it can, if not cleared become 2 line to ground and then involve all 3 phases. In many cases single pole clearing and reclosure works well.
--

Don Kelly snipped-for-privacy@shawcross.ca
remove the X to answer
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Look again. THAT WAS a three phase line, but only two lines were arcing.
Nice guess though.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 15 May 2007 07:29:29 GMT, snipped-for-privacy@cucumber.demon.co.uk (Andrew Gabriel) wrote:

Totally incorrect. Such arcs operate on the rise of heat in air. This was HORIZONTAL.
Think before you speak, boy.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
---------------------------- "The Great Attractor"
writes:

--------------
There is a short between lines - current flows- magnetic force is present and tends to expand the loop and this alone can cause movement of the arc (and is also a major factor in Jacob's Ladders-more so than thermal effects). This arc had little upward expansion so heating wasn't the source. A horizontal Jacobs ladder should work. Fats, you should be able to try this.
--

Don Kelly snipped-for-privacy@shawcross.ca
remove the X to answer
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

I have had jacob's ladders where the arc sits at the bottom without moving up the conductor pair at all.
The thing needed adjustment, and the ACTION was effected by THERMAL energy carrying the arc up the non parallel conductor pair. Since the top is wide, when the arc finally quenched, a new arc forms at the bottom (least resistance path), and the process starts again.
It is 100% thermal in air, with the ONLY exception being in a vacuum vessel. Then, I would suspect that there is STILL some air in there.
Are there DC Jacob's ladders?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
"The Great Attractor"
remove the X to answer ----------------------------
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Another horizontal Jacob's Ladder of sorts.

http://www.youtube.com/watch?v=-Q7qATVBEW8&mode=related&search

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
| Confetti causes a flash over between power line conductors. I wonder why it | travels horizontally like that? |
http://www.youtube.com/watch?v
XAonbevaA | | I thought this one was pretty neat. A linesman servicing HV lines from a | chopper. |
http://www.youtube.com/watch?v=HcalasGr_uk&mode=related&search
Do you have normal videos for these? YouTube still can't figure out what version of Flash player my browser has (likely because their code does not understand Linux).
--
|---------------------------------------/----------------------------------|
| Phil Howard KA9WGN (ka9wgn.ham.org) / Do not send to the address below |
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 15 May 2007 12:31:24 GMT, snipped-for-privacy@ipal.net wrote:

What I hate is all these damned sites that allow one to view, but not save a clip.
They act like they are going to lose money or some such SPAM related CRAP.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Wed, 16 May 2007 02:49:32 -0700 The Great Attractor
| On 15 May 2007 12:31:24 GMT, snipped-for-privacy@ipal.net wrote: |
|> |>| Confetti causes a flash over between power line conductors. I wonder why it |>| travels horizontally like that? |>|
http://www.youtube.com/watch?v
XAonbevaA
|>| |>| I thought this one was pretty neat. A linesman servicing HV lines from a |>| chopper. |>|
http://www.youtube.com/watch?v=HcalasGr_uk&mode=related&search
|>
|>Do you have normal videos for these? YouTube still can't figure out what |>version of Flash player my browser has (likely because their code does not |>understand Linux). | | | What I hate is all these damned sites that allow one to view, but not | save a clip. | | They act like they are going to lose money or some such SPAM related | CRAP.
If you can view it, you can save it. You just have to be using software that obeys the user, or something sniffing the video card buffers. BTW, features in the new Vista from Microsoft intentonally try to prevent that.
I would not mind watching the video directly from YouTube, if they would make it work universally. But that probably means they would ose certain abilities to control other people.
--
|---------------------------------------/----------------------------------|
| Phil Howard KA9WGN (ka9wgn.ham.org) / Do not send to the address below |
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 16 May 2007 13:15:59 GMT, snipped-for-privacy@ipal.net wrote:

Try "Devil Ducky" and hunt up the same clip.
http://www.devilducky.com/all /
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
snipped-for-privacy@ipal.net writes:

That's true. There are some nice extensions for Firefox web broser that allows you to easily download videos from many sites, including YouTube. Use Firefox web browser with VideoDownloader plug-in and you can download videos easily. Get fre FLV player application and you can play easily those downloaded flash videos.

--
Tomi Engdahl (http://www.iki.fi/then /)
Take a look at my electronics web links and documents at
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Some local lines have coatings on them, and the burn travels along as the coating is breeched.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Polytechforum.com is a website by engineers for engineers. It is not affiliated with any of manufacturers or vendors discussed here. All logos and trade names are the property of their respective owners.