Fritz Adalis
MissInformationsomething, something energy conductor
Risa Spirelli@MissInformation was sehen wir da??
@risa_spirelli eine Leiter unter starker Spannung, teilweise geschmolzen.
@risa_spirelli Ja sollte man nicht versuchen hochzuklettern im Moment. Vielleicht später 😬
Christian Gudrian@MissInformation Kein Problem. Ist geerdet. @risa_spirelli
Sir Toootenstein
Michael@MissInformation die Leiter 🤝 der Leiter
kravietz 🦇@MissInformation What a fantastic resistance heater 🤩
Alexander Knochel@MissInformation In German, you could make a joke about Hochleistungs--Halbleiter
Hans Hafner
diana 🏳️⚧️🦋🌱I found the most voltage concrete can handle is about 2,000 volts. After that, it's like an explosive conductor of electricity and starts melting, blowing chunks at high speeds, and melting.
Aerofreak | USA WTF?I think it's not the concrete, but the aluminum here. At the contact resistance.
It first starts with the water absorbed in the concrete, like gypsum does. Then it effectively turns into a silicon "always on SCR" that never unlatches...
Carola Meyer@dianea @aerofreak @MissInformation
But it is not the voltage. If no current would flow, nothing would happen. It is the power that is dissipated that starts the fire. Power is voltage times current. Aluminium is a good conductor, though. What happened to the person that put the ladder there? Could not have been very healthy either.
@carbonwoman
Yes, the current must be enormous here (don't think they deliver kilovolts in that height). Still I wonder why this hasn't blown a fuse or activated disconnection.
felis_catus_domesticus
2xfo@dianea @aerofreak @MissInformation
Now I'm curious if concrete can be doped to form functional high voltage semiconductors. (And after that i wonder what possible application that would have, but mostly it's the first thing)
Now I'm curious if concrete can be doped to form functional high voltage semiconductors. (And after that i wonder what possible application that would have, but mostly it's the first thing)
Laberpferd@RnDanger
Concrete is not a semiconductor, so no
At low temperatures concrete is a weak isolator, with pore water and salt ions acting as electrolytic conductor
With increasing temperature it gradually turns from solvated salt electrolysis to molten salt electrolsyis
If it would have been a DC line you could have watched the seperation into something gassy on one side and a blob of reduced metals in the other side
(known failure of tramway feeder cables)
@Laberpferd @RnDanger @aerofreak @MissInformation
Plot twist: it's no longer concrete 😋
@dianea
That makes sense. You seem to know a lot more about it than I do. 😊
Thanks for the details!
DamonHD@dianea @MissInformation Pray tell, how did you find that, pretty pretty please? B^>
One of the jobs I had was maintaining high voltage destructive cable testers. They ranged in size from small portable units to rooms with bomb proof doors with oil cooled transformers and voltage multipliers after the 150KV.
I found after a thousand volts, ordinary objects behave a lot differently. Anything can be a conductor or semiconductor if the voltage is high enough. I hear many say it's the current, but I've seen very large voltages at milliamps do major wattage events.
That aluminum ladder could be passing only 10 amperes of current, but at 14,400 volts, that would be nearly 150KW, which would be a blazing arc lamp with plenty of UV-C and possibly x-ray radiation too. Most people don't try to measure that, but I did...
Matt Hall
DavidThe Forbidden Ladder
Martin Vogel@MissInformation
The floor is lava.
The floor is lava.
C++ Wage SlaveI wonder why the system can leak so much current to earth and still not cut out.
I also wonder about the voltage on those transmission lines, right outside people's houses.
sahqon@CppGuy @MissInformation I also wonder where the guy who put that there is?
zbrown@zbrown @sahqon @MissInformation
I really hope whoever left the ladder there didn't get a jolt. That doesn't look survivable.
With lowish voltages you could just knock the ladder away with a dry wooden broom handle. With this, though…
@CppGuy @sahqon @MissInformation that nobody is attached is reassuring, with a bit of luck they'd already let go before contact was made
Dusk To Don 
@CppGuy @zbrown @sahqon @MissInformation
Found 'em*
wee CW: the audio in the video includes the videographer saying "dickhead" repeatedly in response to the driver doing something reckless with a bucket truck + power lines.
*jk, this is unrelated
Shiitake Toast
zhe mosslet [Viridi Vix]because vehicles famously cannot travel from place to place, certainly not across state borders, and most especially between two spatially adjacent states...
Chris Deluca
Phil Thane ✅
Oblomov
pst@sahqon @CppGuy @MissInformation
Hope it's not him doing the bubbling?
Must be a him, no?
🇺🇦 haxadecimal@CppGuy @MissInformation
Because the system carries thousands of amps under normal conditions. This isn't enough to register as a fault.
Because the system carries thousands of amps under normal conditions. This isn't enough to register as a fault.
jan guerillahandwerker ullrich@brouhaha @CppGuy @MissInformation typically you find a ground fault detection independent from amps and current monitoring
@young_ullrich @CppGuy @MissInformation
I haven't seen that in neighborhood distribution, but I'm not a power distribution engineer. Even so, the fault current to trip it would have to be quite high.
I haven't seen that in neighborhood distribution, but I'm not a power distribution engineer. Even so, the fault current to trip it would have to be quite high.
I guess you don't want a domestic wiring problem taking out the power for the whole neighborhood. But this is not that. 😄
@brouhaha @CppGuy @MissInformation not sure about the oversea way of doing electricity, but that's a common thing in europe.
John Francis 🦫🇨🇦🍁💪⬆️@brouhaha @young_ullrich @CppGuy @MissInformation distribution circuits don't have any neutral line returning upstream. The neutral in a household circuit is bonded to ground in the panel. Ground fault detection is between live & neutral. Distribution is to ground via load. The molten ladder is an acceptable load.
@brouhaha @young_ullrich @CppGuy @MissInformation if the ladder gets a top high voltage wire, its also beyond the fuse coming out of the service transformer.
I wonder if the auditors will notice they didn't seem to get paid enough for that neighbourhood distribution circuit.
I'm unsure of some of the terminology here (especially panel) but, here in the UK, we do get an earth line from the 230V transformer to the house. I know more about that than I want to because of fun and games getting an adequate supply to our new heat pumps.
I have no idea on what goes into that transformer, so, if you're saying that an 11kV supply has no earth then I'm not arguing.
@CppGuy @brouhaha @young_ullrich @MissInformation we also get an earth from the circuit breaker panel in the house to the nearest transformer, but it doesn't go back any further. My nearest transformer is fed by a single high-voltage wire, something around 3-6 KV. That's the ladder liquifier, it live right at the very top of the poles. To keep the local bumbling telco contractors from touching it.
@johnefrancis @CppGuy @brouhaha @young_ullrich As a person from a country where the energy network is largely buried in the ground, I am always amazed at the structure of energy networks in other countries. 😁
@MissInformation @CppGuy @brouhaha @young_ullrich some is buried here, in new construction, dense urban environments. But overall it's tough to beat just hanging the wires on specially prepared trees for cheap.
Bruce Heerssen@johnefrancis @brouhaha @young_ullrich @CppGuy @MissInformation
Anyway, the ladder will eventually melt down enough to fall away from the transmission line and the problem will correct itself.
Poul-Henning Kamp@brouhaha @CppGuy @MissInformation
I somewhat doubt that it is "thousands of amps", because rule of thumb is "max 1kA per conductor" and I only see one wire.
I find it far more likely that there is an arc between the ladder and something well-grounded just below street-level.
Arcs do not need to draw a lot of current to generate a lot of heat (ie: arc-welding).
But "100's of amps" through a high voltage arc is still plenty energy to melt many things including concrete.
The alu-ladder has a big cross-section and good thermal conductivity. It will eventually melt, but not any time soon, probably just a couple of cm per minute.
But it does not look like a single-wire+ground distribution system, so the up-stream earth-fault should have triggered long ago.
Ysegrim@CppGuy @MissInformation You have never been to the US, have you?
Heh! A few times, yes, but it was back around the turn of the century, and I didn't study the wiring. 😄
@CppGuy @MissInformation Basically, whenever you see one of those tin can shaped transformers on a pole, what goes in has at least 13kV.
F4GRX Sébastien@CppGuy @MissInformation I am also surprised that this circuit drives enough current to melt metal without melting the supply wires or blowing the transformer safety fuses.
It does not seem to be slop.
I wonder if what we're seeing is dielectric breakdown of the road surface, and that's where the heat is being generated, rather than in the ladder.
Edit: wrong jargon. It's a very long time since I was in school!
@CppGuy @MissInformation could be.
after all there should be enough coal and carbon in the road coating material (tar?) to generate some resistive heating without blowing any fuse (less likely to blow fuses at least), while the ladder just conducts the current into the melt.
Once there is a molten pool electrolysis could also play a role, idk.
Anyeay thats certainly an unplanned "lucky" situation :)