In some cases, testing for the most common errors or types of short circuit. In other cases it is merely a case of: "So, we designed something according to what we know about material specifications, and now we want to know how it behaves when there are fault conditions. We want to know what safety precautions to take, or if it's a case of "back to the drawing board."
We used to do low voltage short circuit tests. Blew 3 fuses behind a breaker for each test. 480VAC output, 90% load, 2000A CB at the pickoff point and 1000A fuses at the output of the CB. The idea was when the test took place it would show as a tiny deviation in voltage. Great - till someone decided to just use a shorting bar across the output of breaker. Then, one day, the breaker caught fire and didn’t open. The UPS breakers all tripped on a fault. There goes that short circuit test. Ha! Ha! And the breaker.
Where’s the hot chick from the Native ads? Clickbaited again. What is this junk anyway? In the US we have clothesline hung on the pole with coat hangers, and everybody gets on fine. Also, them trucks got too many tires; there’s where all your climate change is coming from. A butterfly flaps its wings… and blows that crap over here. Seriously though… all them fignewtons from the induction scienced me. I thought you had to have coils to get that like those “can crushers” and proposed nuclear futon things. Coathangers man, you ain’t got to test them
Now THAT is an AED! I would like it so much bettet if the editor realized that normal people can't read that fast. I read very fast, but not that fast.
That is a lot of juice. 63KA at 375kv.. Had 3KA at 5kV through quad aught cable in a single 3mS pulse that made it dance on a powerful laser setup. YOUR rig definitely tops that by a bit🤪
Most likely this was not 275 kV: the air-gaps between the conductors at the feeding end would be far too small to sustain that voltage. Short circuit tests like these are most likely more down to check if the cables sustain physical damage (or even total failure) in short circuit conditions considering the forces the cables, supports and cleats have to endure. Thus it's more about Amps than Volts.
Given the quality of the short, I’d assume on the order of 0.01 ohms, and 63kA, ignoring reactive components puts the voltage under 1kV ballpark. I’d guess for the 63kA desired fault current they used their 12-ish kV phase-phase transformer, whatever that is in 50Hz land, and interrupted its primary side to control the experiment, which was really well thought out though today would be worthy of 4K 120p, a photographic scale backdrop, and a nice 200mm lens. I’ve seen a small 2kA inrush make 4/0 awg (100-ish mm2) get up and dance in a 100 foot long aerial drop. Those clamps performed admirably!
@@swsuwaveI think so too. Conductor-to-conductor resistance is the most important factor here and most likely will have been accurately measured before testing commenced. Not only because it's a test, but because this is done in the field in real-world situations as well. Judging by the massive short they create and the slight decrease in frequency that can be heard, this was done using a rotary converter or even a flywheel-converter (They had one in the past if I remember it right, don't know if they still do). This all to keep the national grid from sustaining severe dips whenever they would perform a big short circuit test. You can hear the effect quite clearly in these videos: ua-cam.com/video/le3-fwsDxLs/v-deo.html and ua-cam.com/video/igh6Cj3C9pw/v-deo.html I have no idea if the clamps passed the test or not ;) sometimes tolerances are down to minimums we can hardly imagine considering the forces that strain those cables during a short. If you're in for a bit of a bang, this is definitely one to watch ;) ua-cam.com/video/avppv8ljRVo/v-deo.html
Mwah, toch moet je niet onderschatten hoe erg dat al fout kan gaan ;) Maar toch sluit ik nog liever een gewoon 16A beveiligd stopcontact kort dan een gemiddelde accu.
Was hoping for a test to destruction! I know that the point was a survivability test. But nothing exciting about a succesful jet engine test on a stand either , that is, until you drop a frozen turkey into it at full throttle!
Iam sure it will be very interesting when they realease all power on longer time lets say 400Kv:) I know those short test make sense but you know for maximum destruction i want see what give up first cable or that steel thing on end.
@@joe125ful We have had a massive short circuit fault in The Netherlands in september 2022 that did this: ua-cam.com/video/9JKgGESux94/v-deo.html Some of the research indicated the distribution line that sagged carried 4 or even 6 times over it's maximum amount of current. At some points the lines were 50 cm's from the ground due to how exceptionally hot they became. This happened after a couple of safety systems had been deactivated for maintenance, and the last-resort type of system still active, failed spectacularly. Downstream city substations started noticing things were off due to stray voltages (a line contacted the ground and caused grounds in other systems to become disrupted) and voltages on phases that were way above normal (240V is normal, but some neighbourhoods saw 380 or more) and decided to kill power, eventually stopping the problem upstream. The sagging line also came into contact with the 1500VDC overhead wiring system that our regular trains run on, causing people to witness breakers in the poles to explode or catch fire, along with stray currents (and very high ones at that) trying to find their way from the rails into the ground making the ground smoke. We had a drought at the time and it we were INCREDIBLY lucky this didn't spawn several massive wildfires, nor were there any injuries.
Yes, it's to retain the cables in the event of fault currents. The cables will whip about due to the extremely large magnetic forces that are generated when a very large fault current flow. Don't know if it's on UA-cam but I saw a film of some very high-capacity fuse tests in a high-voltage cabinet where the cables weren't secured sufficiently and the cables broke away and whipped about causing secondary flashover, short circuits and fire.
@@jameswest8280 That would only be if the cables were superconductors, so in theory it should not be zero but sure much lower than the power source voltage.
Don’t let audiophiles see this cable
Is Skin Effect really that shallow? at audio
@@jagmarc skin depth is around 0.5mm at 20k in copper
63,000 amps, that's a lot.
And that's RMS, so at DC level. If they used 50Hz AC (which I assume), you'd see 63000 A * 1.41 = 88830 A peak current. Ouch.
@@adev8565 electric arc furnaces use 40,000+ amps and 80 MVA or more.
nah, not really
Excelentes profissionais
How to create fault and testing procedure or equipment?
In some cases, testing for the most common errors or types of short circuit. In other cases it is merely a case of: "So, we designed something according to what we know about material specifications, and now we want to know how it behaves when there are fault conditions. We want to know what safety precautions to take, or if it's a case of "back to the drawing board."
Muhammad ridhauddin binti roslan&cikgu gani
碍子を使わないで問題ないのかと思った。電磁作用でフレームにも影響があるだろうと思う。
そうすると、３本のケーブルにも相互影響があるのでは❓
That's some damn fine demo music.
We used to do low voltage short circuit tests. Blew 3 fuses behind a breaker for each test. 480VAC output, 90% load, 2000A CB at the pickoff point and 1000A fuses at the output of the CB. The idea was when the test took place it would show as a tiny deviation in voltage. Great - till someone decided to just use a shorting bar across the output of breaker.
Then, one day, the breaker caught fire and didn’t open. The UPS breakers all tripped on a fault. There goes that short circuit test. Ha! Ha! And the breaker.
A fascinating video. But why take all that tackle to Arnhem? Can't those tests be performed in the UK without the expense of the transport? Cheers!
The power levels required for this tests are the main reason why the are only made in certain testing facilities.
So someone has jobs...
Where’s the hot chick from the Native ads? Clickbaited again. What is this junk anyway? In the US we have clothesline hung on the pole with coat hangers, and everybody gets on fine.
Also, them trucks got too many tires; there’s where all your climate change is coming from. A butterfly flaps its wings… and blows that crap over here.
Seriously though… all them fignewtons from the induction scienced me. I thought you had to have coils to get that like those “can crushers” and proposed nuclear futon things.
Coathangers man, you ain’t got to test them
Operation Success but patient died.
Now THAT is an AED!
I would like it so much bettet if the editor realized that normal people can't read that fast. I read very fast, but not that fast.
That is a lot of juice. 63KA at 375kv.. Had 3KA at 5kV through quad aught cable in a single 3mS pulse that made it dance on a powerful laser setup. YOUR rig definitely tops that by a bit🤪
Most likely this was not 275 kV: the air-gaps between the conductors at the feeding end would be far too small to sustain that voltage. Short circuit tests like these are most likely more down to check if the cables sustain physical damage (or even total failure) in short circuit conditions considering the forces the cables, supports and cleats have to endure. Thus it's more about Amps than Volts.
Given the quality of the short, I’d assume on the order of 0.01 ohms, and 63kA, ignoring reactive components puts the voltage under 1kV ballpark. I’d guess for the 63kA desired fault current they used their 12-ish kV phase-phase transformer, whatever that is in 50Hz land, and interrupted its primary side to control the experiment, which was really well thought out though today would be worthy of 4K 120p, a photographic scale backdrop, and a nice 200mm lens. I’ve seen a small 2kA inrush make 4/0 awg (100-ish mm2) get up and dance in a 100 foot long aerial drop. Those clamps performed admirably!
@@swsuwaveI think so too. Conductor-to-conductor resistance is the most important factor here and most likely will have been accurately measured before testing commenced. Not only because it's a test, but because this is done in the field in real-world situations as well.
Judging by the massive short they create and the slight decrease in frequency that can be heard, this was done using a rotary converter or even a flywheel-converter (They had one in the past if I remember it right, don't know if they still do).
This all to keep the national grid from sustaining severe dips whenever they would perform a big short circuit test.
You can hear the effect quite clearly in these videos: ua-cam.com/video/le3-fwsDxLs/v-deo.html and ua-cam.com/video/igh6Cj3C9pw/v-deo.html
I have no idea if the clamps passed the test or not ;) sometimes tolerances are down to minimums we can hardly imagine considering the forces that strain those cables during a short.
If you're in for a bit of a bang, this is definitely one to watch ;) ua-cam.com/video/avppv8ljRVo/v-deo.html
Ah no way, Stalybridge sub...I know exactly where that is, been past it on the train many times!
Ik heb soms backstage "maar" max 63 amp's 😆... althans als de organisatie zijn contract goed leest😂. ua-cam.com/video/gion-N8CRDs/v-deo.html
Mwah, toch moet je niet onderschatten hoe erg dat al fout kan gaan ;)
Maar toch sluit ik nog liever een gewoon 16A beveiligd stopcontact kort dan een gemiddelde accu.
@@weeardguy Zeker, maar alles goed onderverdelen in lagere groepen...
Was hoping for a test to destruction! I know that the point was a survivability test.
But nothing exciting about a succesful jet engine test on a stand either , that is, until you drop a frozen turkey into it at full throttle!
I'm not sure what all that was really about but hey, groovy music baby, yeah.
Why didn't you earth bond the rigs together?
2,500mm2 is quite fat
Iam sure it will be very interesting when they realease all power on longer time lets say 400Kv:)
I know those short test make sense but you know for maximum destruction i want see what give up first cable or that steel thing on end.
@YAKUMO RAN Yeah!Me too!
I think very strong transformer need be used too.
Something with 1MW of power:)
@@joe125ful We have had a massive short circuit fault in The Netherlands in september 2022 that did this:
ua-cam.com/video/9JKgGESux94/v-deo.html
Some of the research indicated the distribution line that sagged carried 4 or even 6 times over it's maximum amount of current.
At some points the lines were 50 cm's from the ground due to how exceptionally hot they became.
This happened after a couple of safety systems had been deactivated for maintenance, and the last-resort type of system still active, failed spectacularly.
Downstream city substations started noticing things were off due to stray voltages (a line contacted the ground and caused grounds in other systems to become disrupted) and voltages on phases that were way above normal (240V is normal, but some neighbourhoods saw 380 or more) and decided to kill power, eventually stopping the problem upstream.
The sagging line also came into contact with the 1500VDC overhead wiring system that our regular trains run on, causing people to witness breakers in the poles to explode or catch fire, along with stray currents (and very high ones at that) trying to find their way from the rails into the ground making the ground smoke.
We had a drought at the time and it we were INCREDIBLY lucky this didn't spawn several massive wildfires, nor were there any injuries.
👍🇵🇹
What is this to prevent ?, some type of cable whip ?
Yes, it's to retain the cables in the event of fault currents. The cables will whip about due to the extremely large magnetic forces that are generated when a very large fault current flow.
Don't know if it's on UA-cam but I saw a film of some very high-capacity fuse tests in a high-voltage cabinet where the cables weren't secured sufficiently and the cables broke away and whipped about causing secondary flashover, short circuits and fire.
How many volts was used?
In a short circuit test the voltage would be theoretically zero.
Probably 275.000 volts KEMA can generate this voltage and current without any problems.
@@jameswest8280 That would only be if the cables were superconductors, so in theory it should not be zero but sure much lower than the power source voltage.
@@teresashinkansen9402 true, there would resistive and inductive losses. Not sure what the voltage drop would be, I imagine a few hundred volts.
The lower the voltage, the higher the short circuit amps, also the resictance Counts