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Bassalisk
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This is pret... appear at all?
Can we discuss this effect?
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I think I understand. (ion part)jim hardy said:you're tapping my oldest memory banks now.
when i was a kid had a next door neighbor hwo was a sort of Sorcerer's Apprentice, making Jacob's Ladders and the like.
I think you'll find the arc went up by simple convection like the smoke did. The ionized air is very hot...
there is a force on the charge that is moving through the arc, Q X Velocity (cross) B
but shouldn't that twist the arc parallel to conductors?
i didn't notice that in the video..
old jm
Bassalisk said:
This is pretty old but it just crossed my mind. Wanted to share it with you guys.
One question though, why is that current arc going upwards? And why did it appear at all?
Can we discuss this effect?
gnurf said:Tree branch "falls" on power lines? From nowhere on a relative wind-free day with cameras ready? Admit it, you threw it up there didn't you?
jim hardy said:""""But this is AC, how does lorentz force apply to this when we have alternating B field."""
B alternates certainly, and so does Velocity (current in the arc is alternating )
i think you're right - if i remember how to cross vectors, the result also alternates direction hence nets to zero... mumble mumble...c'mon old brain,,, V X B--- rotate V into B and result is direction a right hand thread would move?
was hoping youd reaffirm my old memory because i don't have my books handy. (visiting friends away from home)
am i right , my kind friend?
dlgoff said:This old video shows what it looks like when transmission line phases arc.
https://www.youtube.com/watch?v=hIkNY5xjy5k
jim hardy said:memory - i can almost remember when i had one...
jim hardy said:that last video is intentional opening of a disconnect switch in that yard. first second you can see it swing away... that kind of switch cannot interrupt load current, but the simple charging current makes a plenty impressive arc.
so judging by lack of excitement by participants that video, the current was pretty small. i didnt notice molten metal falling...
Maybe I was your neighbor. I've still got my 9KV neon sign transformer.jim hardy said:when i was a kid had a next door neighbor hwo was a sort of Sorcerer's Apprentice, making Jacob's Ladders and the like.
jim hardy said:power side of EE is to me more interesting than computers.
i honestly considered programming but decided it's more fun to magnetize iron by the ton than by the micron.
i was happy with DOS and QBASIC.
but that's just me.
old jim
There are several factors that can cause a tree branch to fall on power lines, including strong winds, heavy snow or ice accumulation, and disease or decay in the tree itself. Additionally, improper tree trimming or maintenance can also increase the risk of branches falling on power lines.
A strange arc, also known as a "corona discharge," is a phenomenon that occurs when high voltage electricity is discharged from a power line to a nearby object, such as a tree branch. This can happen when the air around the object becomes ionized, creating a visible, glowing arc of electricity. It is typically caused by a combination of high humidity, moisture on the surface of the object, and high voltage on the power line.
Yes, a tree branch on power lines can cause a power outage. When a branch falls on power lines, it can disrupt the flow of electricity and cause a short circuit, leading to a power outage. Additionally, if the branch damages the power lines or other equipment, it may take longer to restore power.
If you encounter a tree branch on power lines, do not touch it or attempt to remove it yourself. Always assume that the power lines are still energized and contact your local power company immediately. They will have the necessary training and equipment to safely remove the branch and restore power if needed. It is also important to stay at least 10 feet away from any downed power lines.
Proper tree maintenance and trimming is the best way to prevent tree branches from falling on power lines. Trees should be planted a safe distance away from power lines and regularly inspected for any signs of decay or disease. Trimming should be done by a professional, following established safety guidelines, to ensure that branches do not come in contact with power lines. Additionally, power companies may also trim trees near power lines as part of their regular maintenance to prevent potential outages.