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An alarming flashover.

 
PYE625
(@pye625)
Famed V-Ratter Registered

I happened to see this video and can only be relieved that I do not live near any power lines, however, I would doubt that this could occur in most cases as you would think that there must be safety measures to cut the current in such an event as this. I know very little of power distribution, but surely there would be RCD arrangenments at major substations etc ? Obviously not here.....

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Topic starter Posted : 10/03/2020 6:29 pm
Nuvistor
(@nuvistor)
Famed V-Ratter Registered

At least it was self extinguished. A quick search of power line fires produce this report of fires under HV lines that can cause flash over and fires on the HV lines. Sugar cane fires can be a big problem the intense heat and dust produce corona discharge. Something I have never thought of

https://www.researchgate.net/publication/234058061_The_threat_caused_by_fires_under_high_voltage_lines

 

We had a safety talk many years ago about HV and if you are not trained keep well away. One thing he told us was that HV deaths were very often due to copper poisoning due to the heat melting the copper wire and being transferred in to the burns.

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Posted : 10/03/2020 9:47 pm
Alastair
(@alastair)
Reputable V-Ratter Registered

Hmm--A bit big for a blu-tac plaster!

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Posted : 10/03/2020 11:03 pm
PYE625
(@pye625)
Famed V-Ratter Registered

Here's another one to drool over.... if you like this sort of thing that is ?

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Topic starter Posted : 11/03/2020 10:28 pm
Katie Bush
(@katie-bush)
Illustrious V-Ratter Moderator

Hmm, "Frying tonight!"

So, two lines fell to the ground? Leaving the upper of the three to burn by itself. A good job that all three didn't detach and fall.

I once saw a video from a place in Wales where pylons and power lines were tested to destruction. It gets a bit ugly when the stress loading becomes seriously asymmetric. Pylons are immensely strong under normal loading, but don't take kindly to being loaded on one side only.

This clip reminds me of a late summer night in the early 80s, when we still had overhead power lines down the main street. These were only "low" voltage distribution lines, but the fireworks were still very impressive, as the pitch potted, cast iron junction box on the pole, just across the way from our house, blew its top clean off and the connectors within began to arc and burn. Needless to say, the lights flickered a bit! I called the then YEDL, who sent out an engineer at about 1:30am. My brother and I met him in the street and described what we'd seen. All was quiet and peaceful by then, but the cast iron lid, lying on the pavement, showed the violence by which it was blown off, and the lava like streamers of pitch down the pole, and the pitch "tadpoles" that adorned the nearby hedges gave testimony to the event.   The engineer just looked up the pole, shone his big torch at the pole box and said, "Well, it's all quiet now, I think we'll leave it 'till daylight" - And that was that.

We still had power, and everything seemed normal, though I didn't exactly sleep too easily, knowing that thing was only about 45 feet from my window. Power was still on when I got ready for work, next morning, and the power was still on when I returned in the evening, but by now, the guys had been and re-rigged the connections into individual "potted egg" style insulators.  The overhead power lines came down just a few years later, in favour of a new, underground line.

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Posted : 11/03/2020 10:36 pm