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Fireballs reported in east Fort Worth

Fireballs reported in east Fort Worth

Fireballs reported in east Fort Worth

(OP)
Does anyone know what happened?

There is also a vidio out there of this.

RE: Fireballs reported in east Fort Worth

After watching this video, the only thought that I can come up with is that a higher-voltage subtransmission overbuild was dropped into the distribution line.  If the sub-transmission line failed to trip, the sustained overvoltage could cause successive failures of arrestors and transformers.  Unless it was an arcing fault that never cleared the distribution or sub-transmission lines, it is hard to understand why this went on for so long...

RE: Fireballs reported in east Fort Worth

I saw this on the national news. They reported it as 'transformer explosions' following a lightning strike. But I don't see the oil fires that one would expect if a pole pig failed catastophically.

It appears that there are several locations where arcs restrike. The primary one being a bit to the left of the center of the picture. But the restrikes appear to occur at several locations over and over. So I'd guess that the initial lightning caused multiple insulator failures. The arcs restrike at the weakened insulators or arresters due to system voltage transients. Transients due possibly to breaker reclosing events or perhaps just another arc down the line clearing and the circuit voltage overshooting upon recovery. Hence the cascading sets of flashes at various locations on the circuit.     

RE: Fireballs reported in east Fort Worth

Sounds like they could use some overvoltage protectors!

RE: Fireballs reported in east Fort Worth

Might have been an arcing fault of not sufficient current to trip
overcurrent protection due to depressed voltage under arcing conditions.
A case for voltage sensitive overcurrent protection??

RE: Fireballs reported in east Fort Worth

Too bad no-one can be trusted anymore. The images are identical at times 0:47 and 2:30. So, who knows what else is doctored in this "amazing video".

 

RE: Fireballs reported in east Fort Worth

Well, there's a billboard in town that says that the world is going to end on May 21 ("guaranteed by the Bible"), so it could be related to that. looking around

RE: Fireballs reported in east Fort Worth

I noticed about halfway through there was a glitch and it seemed like they restarted from the beginning.  It didn't seem to me like an attempt to disguise anything... pretty obvious. There were reportedly (*) many other people who saw this, and there are photos taken by others.

(* I read it on the internet.. must be true)

=====================================
(2B)+(2B)'  ?

RE: Fireballs reported in east Fort Worth

I thought that they looked, at first anyway, a lot like the videos we have been seeing of night time cruise missile attacks we have launched on places like Libya and Iraq of late.

The overall effect it had on me was one of realizing just how interconnected everything is. One initial problem fomented problems over a wider area. I half expected to see it expand in an increasing circle...

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RE: Fireballs reported in east Fort Worth

It certainly didn't affect the birds in the local vicinity. They were happily chirping away.

Ausphil

RE: Fireballs reported in east Fort Worth

Now, if this is a dumb question please recoginze that I am an ME who doensn't know anything about electricity except that it can kill you.  That said:

Recently in the area south of Houston there were widespread outages in the League City area due to salt build up on the insulators at certain substations.  The salt build up was due to the lack of rain that would have otherwise helped keep the insulators washed and clean.  After some frantic power washing of the insulators in several key substaions, most of the major industrial plants knocked off were back on line within a day or so.  

Obviously I recognize that East Fort Worth is too far from the sea to have a salt build up problem.  That said:

Could this have been due to carbon and/or dust (ash) build up on the insulators due to the plethora of wild fires upwind of the area?  To me it seems like were that the case, once a single arching event set off a spike or surge, then others on the ragged edge would then 'torch off' as a result.

Could that be what happened here or has my coffee just failed to kick in yet?

rmw
 

RE: Fireballs reported in east Fort Worth

Well, there were several things going within a 1 or 2 mile radius by my judgement. It takes a surge something like 10 usec to travel 2 mils. The time spacing of those events was measured in seconds.  So, if we are to conclude that one flash event caused another, then  it involves more than just a surge traveling from one location to another, perhaps system response to those events (someone measured trip/reclose).  Or perhaps something completely different (I have no idea).

=====================================
(2B)+(2B)'  ?

RE: Fireballs reported in east Fort Worth

Quote (electricpete):

The time spacing of those events was measured in seconds.  So, if we are to conclude that one flash event caused another, then  it involves more than just a surge traveling from one location to another, perhaps system response to those events (someone measured trip/reclose).

Something like: An arc at one point pulls the system voltage down. Once the arc clears, the system voltage rebounds. Much like a switching surge, the rebound causes overvoltages which initiate flashovers at other locations. Its possible that there could be a few second delay from the initiation of an arc to the point at which significant power (and an arc visible at some distance) develops.

It could be the reclose time delay as well. The breaker closing can also generate a switching surge.  

RE: Fireballs reported in east Fort Worth

Switching surges at distribution voltages are not severe enough to cause insulator flashovers.

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