Homeowner shuts down U.S. nuclear plant for 3 days — Tree fell onto transmission line after being

Thanks everyone for your informative replies. They have added to my knowledge and it is truly appreciated.

reply to post by Arbitrageur


Thanks for posting that. I could not see where the trees came up to the level of the lines although to me they seemed to because of camera angle and perspective.

That is one scary video my friend. I cannot even imagine how much knowledge, trust and confidence a person has to have to do this kind of work!

Originally posted by aboutface
That is one scary video my friend. I cannot even imagine how much knowledge, trust and confidence a person has to have to do this kind of work!

You're welcome. Yes it's hard to be sure the trees are actually higher than the lines, but I think they are a little bit from my take on the perspective, though the hilly terrain might be a factor.

I liked that quote at the end of the video, that he's afraid of electricity heights and women. He's apparently conquered all three fears since he's married too.

Originally posted by Zaphod58
reply to post by Arbitrageur

 

If there was more than one line, it's also possible that as it fell it pushed the outside line into one of the other ones.

I want to say impossible, but I'll say highly unlikely instead. Remember those lines whip around in high winds, so they are designed to not touch when outside forces are applied be they from trees or winds. If you're talking about those two conductors in the video the man is climbing on, yes those can touch, but that doesn't cause any major problem if they touch since they are at the same potential, and in fact the worker in the video is shorting them out with no ill effects. They sometimes use multiple conductors at the same potential on lines with voltage that high to reduce corona discharge, which is an unwanted form of power loss that can make the air around the power line glow which is undesirable but not a major problem. So the worst thing that would happen if those touch is a little corona discharge meaning a very slight power loss, not anything that would shut down the circuit.

Originally posted by spolcyc88
reply to post by C0bzz

 

Transmission is done in high voltage low current DC. At least here in the Pacific Northwest, in which most of our power generation is sent to California so the increased losses associated with long distance AC transmission are avoided.

Actually you have both systems, AC and DC, but you're right that the DC intertie is a major conduit to California, where you send your electricity in the summer to power their Air conditioners.

But Californians aren't just leeches who suck up power from the intertie as your comment might suggest. California sends the power back to the Pacific Northwest in the winter when you guys run your heaters!

More info here.

The Pacific Intertie takes advantage of differing power demand patterns between the northwestern and southwestern US. During winter, the northern region operates electrical heating devices while the southern portion uses relatively little electricity. In summer, the north uses little electricity while the south reaches peak demand due to air conditioning usage.

Originally posted by Arbitrageur
I want to say impossible, but I'll say highly unlikely instead. Remember those lines whip around in high winds, so they are designed to not touch when outside forces are applied be they from trees or winds. If you're talking about those two conductors in the video the man is climbing on, yes those can touch, but that doesn't cause any major problem if they touch since they are at the same potential, and in fact the worker in the video is shorting them out with no ill effects. They sometimes use multiple conductors at the same potential on lines with voltage that high to reduce corona discharge, which is an unwanted form of power loss that can make the air around the power line glow which is undesirable but not a major problem. So the worst thing that would happen if those touch is a little corona discharge meaning a very slight power loss, not anything that would shut down the circuit.

A few years ago there was a wildfire that burned something like 5,000 acres that when they found ground zero, they found a squirrel that had touched both wires, and shorted itself, and burst into flame. It was pretty funny, but even though they move around in high winds, a tree hitting them can put more pressure on them than the wind would.

Originally posted by Zaphod58
A few years ago there was a wildfire that burned something like 5,000 acres that when they found ground zero, they found a squirrel that had touched both wires, and shorted itself, and burst into flame. It was pretty funny, but even though they move around in high winds, a tree hitting them can put more pressure on them than the wind would.

Link to source?

Anyway, without seeing the source I can guarantee that didn't happen on a 500 KVA transmission line, the topic of this thread. The lower voltage lines are a bit sloppier so it's more possible on those, but the conductors are simply too far away on a 500KVA line for a squirrel to short them.

When I was growing up our entire neighborhood lost power. The culprit was a squirrel, but he didn't touch two of the not so high voltage residential lines, he gnawed his way through a transformer, so I know that can happen. The line repairman even showed me the dead squirrel, he looked like he didn't have a very good day.

reply to post by Arbitrageur


God, this was back when I lived in Atlanta. I read it at work one day on Yahoo News. I just threw it out there for the laugh to be honest, because it was funny as hell.

But I can see the three pushing the lines together and causing a short somehow.

Speaking of critter problems, we almost had our house catch fire from a gecko. We smelled something burning, traced it to the breaker box, which was hot as hell, opened the door, and one of the breakers was glowing red. The electrician pulled it out, and pulled a little charred corpse of a gecko out.

slightly off topic, but my family is from there and many have been at ORNL for decades.

the lines coming and going from there, WOW from the air.

this is probably the most secretive place in america, and for good reason.

many NEVER realize the stuff that happens here. x-10, k-25, y-12. etc..

i have a lifetime of stories.. many i'll die with.


i promise, a very deep rabbit hole. due to obvious reasons, i can only plant that seed.

reply to post by Arbitrageur


500 kV (Voltage) not 500 kVA (apparent power).