It is a loosely coupled line arcing to ground along several points.
Either a hot phase that was knocked to the ground and is being back feed from 3 phase transformers along the line. Or a ground wire that was melted in
two by lighting and the neutral currents are arcing along wooden poles and pole hardware to the ground.
I would say it’s most likely the latter. The blue lights are metal to metal arcs. The reddish ones are caused by wood being vaporized in the arc.
If it was a multiple phase to ground arc, it would be more violent and trip something. This looks more like it being a limited current arc. That would
be caused by a ground wire being broken and the return current is trying to find a way back. Its arcing across the small spool insulators that most
power companies use to mount the neutral to the pole. The arc current is being limited by the current the load is pulling. It is arcing randomly at
each pole along the line.
Around here, where lighting is common, the power company bonds the neutral to the ground wire running down every pole just because of that situation.
If the neutral is taken out, then the ground return currents can travel back via the natural ground path without the chance of dangerous voltages
building up. And, when lighting hits the ground wire, then the bonding to the ground wire on each pole makes a convenient path for the lighting to
take to ground, without hitting the utility equipment at each end. The ground wire on each pole goes down to the bottom, and is coiled around the
bottom part that is under the ground level. So each pole serves as a ground rod driven in the ground.
From the light display on that video, I can take it that that power company doesn’t have such installation practices.
And a lighting strike doesn’t have to hit right where it burned in two. It could hit anywhere along the line and the weakest link somewhere else
along the line could go first. Like a substandard splice or where a crew used a short section of wire that was a lighter gauge than the rest of the
And I would say that it was a transmission line from a power plant to a substation, not a distribution from a substation to multiple end users. If it
was a distribution line with that much voltage on the neutral, it would cause a lot of damage to a lot of houses.
On second thought…… if there was a long distribution line that went a long distance before it reached the customer base and fanned out, and the
neutral was broke just before it reached the area where it fanned out. Then the substation could be floating above ground. And the arcing would be the
neutral currents from the substation trying to find their way back to the rest of the (better grounded) distribution system.
edit on 11-5-2011
by Mr Tranny because: (no reason given)