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Discussion in 'After Hours Lounge (Off Topic)' started by Scott L, Feb 6, 2004.
Mmmm I love this stuff.
thats one serious jacob's ladder
that is cool, is it a nice special edit or real? if real, is it an accident or intentional. Why or how did it happen?
It looks real and intentional from this extremely untrained eye.
And it's a pretty f'in cool intenentional real clip at that!
I would guess it's real, as you can hear at the end of it someone about to cheer "woohoo" or something to the like.
Pretty amazing nonetheless.
I would have been afraid of it jumping to the nearby power line, then possibly to the person filming it. Course, that owuld probably never happen.
From the sliding elements at the beginning, it looks like a great big electrical switch. Indeed, how do you break such a high-voltage circuit unless you use a switch that big?
My guess is that it's a great big circuit breaker and that somebody donwline dropped a hair dryer in the bathtub.
(Okay, I'm serious about the switch part.)
Agreed. That humongous arc could have been avoided if the switch was faster. There would have been a fash, rather than a sustained arc.
I have witnessed similar stuff, but on a much smaller scale, while testing relays intended to break a large inductive load. On relays that were not up to suff (airgap between contacts was too small ==> dielectric breakdown), the sustained arc would melt the contacts and completely obliterate the device in about 5 seconds, while also creating a fire hazard...
What you saw was a 500KV Line Switch at a SubStation being
opened. They arc like that by design but that particular
switch seems to be bad thus the long duration of the arc.
The funny thing is... On the 138KV Lines they do the same
thing but unlike the 500KV lines the switch is manualy
operated and the handle is basicaly right underneath where
you see that arc!
I work for the power company...
Thanks for taking the time to share your expertise, Brett!
Sweet... made my hair stand up!
I'm pretty sure I saw the outline of my mother-in-law during that arching.
No problem! I just want to make it clear though, that I am
not a lineman or anything of the sort.. I work in I.T
but I have friends who work Power Control and I asked them
what was going on in the video
This is a good explanation from another forum:
"The video clip shows a three phase air disconnect switch attempting to open the high voltage supply to a large three phase 33 Million Volt Ampere Reactive (MVAR) shunt line reactor. The reactor is the huge transformer-like object behind the truck at the far right at the end of the clip. The clip was believed to be part of the 500 kV Lugo substation near Los Angeles, California. Line reactors are large inductors which are used to compensate for the effects of line capacitance on long extra high voltage (EHV) transmission lines. The utility was having difficulty cleanly disconnecting the line reactors and had set up a special test to videotape, and hopefully isolate, the problem. If you look carefully, you can see evidence of previous arcing - notice the blackened horizontal bushing (insulator) just behind the bushing that arcs at the beginning of the mpeg.
Normally, pressurized sulfur hexafluoride (SF6) gas "puffer" interrupters, just to the right of the air break switches, will first de-energize the circuit so that the air break switches can the open with no current flowing. The actual switching elements for the interrupters are hidden inside the horizontal bushings. However, as the interrupters open, a high voltage switching surge causes one of the interrupter bushings to flash over. Since this phase remains energized, the air break switch for this phase opens "hot", and it continues arcing as the switch swings to the fully "open" position. The arc continues to grow upward, driven by rising hot gases and writhing from small air currents, until it easily exceeds 50 feet. Long arcs usually terminate before by connecting to an adjacent phase or to ground, causing a detectable fault which then trips out the circuit. This particular arc could have persisted for quite some time, but the utility manually commanded an upstream Oil Circuit Breaker (OCB) to open, abruptly extinguishing it.
As impressive as this may be, the air switch was NOT disconnecting a real load. The arc is "only" carrying the relatively low (perhaps ~20 amp) magnetizing current associated with the line reactor. The 94 mile transmission line associated with the above circuit normally carries over 1,000 megawatts (MW) of power between Nevada and California. An actual break under normal loading conditions would have been MUCH hotter and extremely destructive. Imagine a fatter, blindingly blue-white, 100 foot long welding arc that would vaporize the contacts on the air break switch and then work its way back to the feeders. But, you've gotta' admit that this "little" 10 million Volt Ampere reactive arc is still pretty awe inspiring.
AKA this is the record holder for the world's biggest Jacob's Ladder."
LOL Sounds like that guy knows his arc's and ampere's
"Only 20 amps" yeah that's not much! Just enough to kill
you 19.5 times!
I've seen more amps at the Mall of America.
That was really cool!
I experienced something similar to that one summer while working for the local telephone company. Me and another fellow were doing some line installs using a little trenching tractor. This was at a power generating dam...the largest in the province. We were trenching from one building to another that happened to be right beside a huge area of transformers and switches etc like seen in the video. So, there we are trenching along and suddenly *WHAM* a sound like a house circuit breaker times 1000 and then the connectors like those in the video start opening up and lightning starts arcing...well shit! We thought we hit a line with our trencher and were about to blow up the whole dam place (dam place...get it?) and blow us up along with it!
Anyway, it turns out that they were just testing something and did not bother to let us know. Just a good scary memory now.
OMG, it's hard for me to believe this was nearly 6 months ago.