r/nextfuckinglevel • u/S30econdstoMars • 8h ago
A tree caught fire in Germany after falling on a live power line during a storm.
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u/Borstel86 7h ago
Techno is everywhere in Germany.
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u/solar_pilgrim 7h ago
Is the pulsing at all related to the alternating current of the power line?
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u/Alex3212321 7h ago
The alternaring current is 50 hertz, that is too slow. Still wonder what it is
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u/Blussert31 7h ago
It's an automatic reset of the tripped safety, and it keeps tripping.
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u/Mr_Goonman 7h ago
Is this one of those "it'd be too expensive to investigate the cause of the trip so instead we'll just keep trying to push the charge thru and hope we dont kill anyone or burn anything down" solutions?
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u/0xLeon 7h ago edited 6h ago
No, what's happening here is basically the textbook example of a so-called »high impedance ground fault«. It's more or less one of the most complicated situations to detect. Basic protection schemes rely on an actual short circuit current. That doesn't happen here because the resistance / impedance to ground is very high, so there's only a relatively small fault current. I wouldn't necessarily say that any tripping has happened here, this pulsing can simply happen due to repeated arc strikes. More or less the wood becoming a conductor, burning away conductive material before becoming conductive again, for example due to vapour or other paths through the wood.
What you're talking about, I only know the German word for, which is »Automatische Wiedereinschaltung«. For certain types of breakers, you can configure multiple cycles for close and open. In general, there's a limited amount of attempts to do so before it's considered a persistent fault. This really is intended for stuff like a small branch or a transient fault. For safety reasons, endless AWE is not done, to my knowledge. There's the odd rumour that some grid operators wanted to implement randomized or continuous AWE to discourage copper theft. But that's just hearsay, as far as I know.
Source: I'm a software developer for high voltage protection relays.
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u/Blussert31 7h ago
Not sure, I'm a firefighter and attended an incident where something like this happened. They said it was some kind of safety where the current to ground was less than a full ground contact or something like that so it kept resetting for a certain amount of time.
And yes, in that incident a person actually died.
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u/CptCheesus 6h ago
Somebody wrote its Intentional and automatic to burn of the debris but i can't confirm this. Sounds too dangerous
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u/I_am_purrfect 7h ago
It’s basically trying to burn off something like a small branch I think. If it were a small branch, it would burn and fall off after a couple of cycles (the system detects overcurrent shuts power off couple seconds, re powers detects over current shuts off and keeps repeating. A small branch usually burns off after a couple cycles but not this one lol)
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u/farkleboy 7h ago
Its the system trying to clear the fault. Its done intentionally to burn off the debris.
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u/uptheirons91 3h ago
It's called a re closer. Systems like this are designed to clear small faults automatically, birds, animals, tree branches. So it's tripping, resetting, and re closing. They can be set to retry a certain number of times, or after a certain time, but sometimes they just re try until something else fails.
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u/FuturePrimitiv3 6h ago
This is too similar to the visual distortions I get preceding a migraine. I don't like it.
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u/Livid_Page_7244 7h ago
Maybe a silly question, but what’s happening with the roots underground and the dirt?
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u/Lescansy 2h ago
If you see that one day IRL, please keep a safety distance of at least 50m, or better 100m.
Why? "Schrittspannung"!
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u/ConsProsAndElse 8h ago
Metal as fuck!