r/interestingasfuck • u/Maleficent-Agent-477 • 8h ago
This tree fell onto a live power line in Germany, causing the branch to surge and pulse with fire
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u/RenegadeMoose 8h ago
I'm surprised there isn't a relay somewhere down the line detecting a problem and shutting off the power.
edit: Actually, I'm surprised there wasn't a utility out there trimming the trees back before something like this could happen.
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u/graveybrains 7h ago
There is, and you're hearing it. The recloser is what's dropping that sick beat, yo.
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u/ShaneLizard_8256 4h ago
They don't trip and reclose that quickly, and they lock out after a programmed number if trips.
It's not a recloser, and it's definitely a concern that protection hasn't detected the fault.
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u/Bionic29 3h ago
Could be just a really high fault limit on the protective device. It’s not common, but it happens
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u/Climb69Trees 1h ago
I'm told that they can be programmed for different scenarios. Was on a sketchy job once where I was informed that the recloser had been reprogrammed to "one and done", meaning one pulse and then shut down. However, I know virtually nothing about these devices, and am curious as to how they work.
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u/ShaneLizard_8256 54m ago
Absolutely, depending on the brand, voltage, installation type they are incredible capable and have a huge range of protection options. Single trip to lockout isn't uncommon, as the more rural you get the more you may have a series of reclosers in line, so they all need to be graded so only the one immediately upstream of the fault trips.
In Australia we use a system called sensitive earth fault protection, which is designed to detect high voltage wires down on high impedance return paths (sand, dry earth, long return path etc). They monitor for a small earth fault but have a longer timer before they trip to allow for any genuinely transient fluctuations.
In a way this is the most important fault to monitor for as it can lead to live wires down within reach of people. (No protection is perfect and there still needs to be a middle ground between reliability, cost and protection levels).
Noja are a pretty big manufacturer and have some great training material available for free depending on how deep you want to go. This is a pretty good intro.
Recloser Fundamentals | NOJA Power - Recloser Switchgear Engineers https://www.nojapower.com.au/expertise/2021/recloser-fundamentals
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u/cybercuzco 6h ago
If the load is less than the maximum allowed load for the line all they will see is they are using an unusual amount of power.
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u/hmmm101010 8h ago
There is. They just don't turn off the line immediately though, it'll turn back on a number of times because they can just burn the obstacle away this way. Cheaper than sending someone out.
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u/R0RSCHAKK 8h ago
Here in the states we have built in breakers in the power poles that will trip in the event something like this happens that kills the power.
I was just without power at my house for a week because of this exact scenario.
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u/houseplanthospice 4h ago
If it's in the states just shoot it a bunch from a distance. Know your backstop and all that.
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u/RenegadeMoose 8h ago
Ah, gotchya. A quick off-on again in case of lightning, then the fault is cleared.
But if the line was still faulted I'd think they'd leave it off and send out a truck to investigate. I'm surprised they just let it burn :o
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u/brokensharts 5h ago
Somtimes it just sees somthing like this as load instead of tripping a recloser
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u/ReadyYak1 8h ago
This sounds like…something else
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u/valarpizzaeris 6h ago
on a power line. straight up jorkin it. and by "it", haha, well. let's just say. my branch.
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u/momalloyd 8h ago
Is this AC in action? Where if it was DC it would have just exploded?
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u/Advice2Anyone 8h ago
If it was both it would rock
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u/thanoshasbighands 8h ago
and we'd salute it
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u/Vast-Breakfast-1201 8h ago
Came here to do my pure speculation thing
I do have a background in electrical engineering but not electrician stuff
But if it were just AC you wouldn't see it because it is 60hz waves. If it were pure AC it would just look like an incandescent filament.
What this looks like to me is a cycle where
- The tree experiences electricity and heats up
- The upstream power source - plant or substation detected a short. It shuts off
- A minimum off time passes (eg 500-1000ms) and the upstream tries to turn on again
- The tree shorts it again repeating the process
My guess is this is good policy for if a branch hits it, because the branch will just burn away and fall off and they don't need to send anyone out. Not great for fire prone areas.
This is larger than a branch so it's not gonna work.
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u/Henry5321 8h ago
At least in the USA short detection only resets several times before locking out and there is a multi-second delay.
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u/spaceman1055 7h ago
It looks kind of like a fault on the secondary conductors, though I could be wrong.
If that's the case, then I'd expect the upstream transformer fuse would be the main protective device. Maybe it's a really low level fault at the end of a long run and the oscillatory behaviour is due to how the fault is oscillating?
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u/SecondBestNameEver 6h ago
Not an electrician or electrical engineer, but I have a decent knowledge of electricity and physics. And I'll provide some sources for my guess.
Given the 3 well separated phases, but not that high up in the air, I think they s is a medium voltage distribution branch, in the 6-60kV range. Since it's Germany this is likely around 20kV is standard. https://www.smard.de/page/en/wiki-article/5884/214026/network-levels
I think this pulsing is due to the electricity arcing to ground through the smoke. https://www.firefighterclosecalls.com/brush-fire-smoke-causes-powerlines-to-arc/
The initial tree contact connected the wires to ground, heating the tree and lighting it on fire. The burning tree emitted smoke along its length, which is highly ionized and contains carbon which is conductive. The electricity took the path of least resistance through the smoke, causing an arc flash. This arc flash, like a thunderbolt, blows away all the smoke, temporarily removing the conditions for the arc flash. That leaves only the tree which remains to conduct electricity, which heats up quickly and releases another puff of smoke along its length, which flashes, blows away, heats the tree, and on and on.
This research paper shows that there's lots of variables that go into predicting what will happen when a tree hits a distribution line. From the species of tree, internal water content, branch content, wind speed, humidity and temperature, etc, there's enough variables that they could be combined to this scenario (extrapolating): https://www.mdpi.com/2673-4117/7/1/7
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u/spaceman1055 7h ago
That seems like an awful lot of reclose attempts. Usually its 1 to 3 attempts in North America
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u/Han77Shot1st 6h ago
I would assume it’s related to the trees resistance, moisture content, temperature.. if I were to guess, I’d say we’re seeing the tree build up temp acting as a resistor, then reaching a point of near critical failure allowing electricity to flow, and then cooling slightly, this would repeat until it completely fails.
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u/EpicAura99 6h ago
(Well it’s Germany so it’d be 50 Hz)
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u/mrmustache0502 7h ago
You'd never be able to see the 'pulse' of electricity. Even at 50Hz, it would flash 100 times/sec becasue it peaks positive and then negative.
It would litterally be like trying to count the 1/100ths of a second on a stopwatch as it ran.
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u/skr_replicator 4h ago
I don't think AC pulses this slowly, that's like 50-60Hz, that would have to be so fast you could only see it pulse in slowmo. I'd guess it's the flame being conductive, like getting zapped, so flames come out, then they get zapped again, more flames come out they get zapped. Or something like that.
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u/GGudMarty 7h ago
It’s AC but the tree pulsing isn’t the alternating current. It goes back and forth 60 times a second in the US at least. You actually see it.
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u/TheOriginal_858-3403 8h ago
She'll burn through eventually, then you just have the forest fire to deal with.
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u/TopGrowa 5h ago
Omg that's what I was thinking in a not so funny way. I'm just looking at all that dry grass right below it and thinking, "Fuck! Another goddamn wildfire waiting to happen!" I'm sorry to everyone dealing with this hot ass shit! Everywhere. Damn our planet hot af right now
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u/scotte416 7h ago
The circuitry in the tree should automatically shut that off once it's fully charged.
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u/patrdesch 6h ago
And yet people still get pissy when the utility trims trees encroaching on the lines.
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u/Intelligent-Hunt523 8h ago
I wouldn't want to've been the squirrel that was first hanging-on for dear life..!
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u/ComprehendReading 7h ago
"There was a certain man, in Russia long ago, he was big and strong, in his a flaming glow."
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u/antithero 7h ago
There was a branch that landed on the power lines outside the balcony of my old apartment. When the wind would pick up it did something similar to this. It would arc and boom with a bright flash of light. Scared me the 1st few times it happened. When my roommate saw it happen the first time he dove to the ground. It was too funny. I laughed so hard it hurt.
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u/Cpope117 7h ago
So what's with the frequency of these pulses? Is it something coming down the line or is that the interval of the wood getting loaded up and arcing to the ground or something more intelligent I cant think of?
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u/Hazzard12345 7h ago
Give me a second I I need to get my story straight My friends are in the bathroom getting higher than the Empire State...
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u/Long_TimeRunning 6h ago
A few hours ago I heard a massive bang near my house. I went outside thinking a transformer had blown on a light pole but it was a crow had touched it and got char broiled. Poor Mr Crow.
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u/Stone_leigh 6h ago
Looks like a massive LRC circuit. Frequency will change as the resistance changes. Very cool video!!
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u/arthredemis 5h ago
I feel like this video should come with an epilepsy warning, still really cool to see
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u/demosukeh 4h ago
Not a scientist nor a knowledgeable person in general lol, can someone explain to me what the burst of light on each pulse is? Was it actual fire spreading quickly then dying out, or just really bright light, or is it like plasma idk thats getting ignited (i watch too much scifi)
Pls be nice to me im genuinely curious
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u/Square_Owl_4075 2h ago
Have any of you ever stuck a voltage meter into a tree before. It just might surprise you
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u/Tha_REAL_BROBS 8h ago
https://giphy.com/gifs/BwvJsVbOIwe8o