We were taught to open single phase switchgear in A-C-B sequence, not A-B-C as shown in the Video. This lessens the chance of the 2nd Isolator (which draws the biggest arc) arcing across to a live phase causing a phase to phase fault which could take the feeder out, not to mention causing an explosion and damaging the hardware.
dont know about america (im assumeing this is usa as we dont have these on 33kv in blighty) but our rods are tested yearly to 75 kva per inch, so as long as your nuts are big enough, no worrys!
anybody knows if there is a specific reason why the last disconnector did not have a big acr like the rest? Less load? Better maintenance? just curious...
Hard to say what kind of a trans bank that line is feeding but if it is an open delta the second cutout usually arcs more than the first cutout. Can't explain the theory thats just the way it is . I think someone told "phase resonance or the like of that.
I re-read your question the second cutout was likely connected via the windings of the B pase transformer to the third cutout. when the second cutout is opened it is braking a phase to phase condition. When the third is opened it is just droppping potential of the transformer windings.
The arc is produced when opening the links on a 70 kilometre line. There is nothing at all connectecd to the line. The arc is capacitance / inductance.
Load, either reactive or capacitive, is related to the arcs that form when you disconect this loads. This is just why you have to turn off the load of a transformer when you are going to move the voltage regulator tap. In the circuit of the video, by the position of the fuses it seems that the cables on the right are the feeders and the left ones go to load, which is likely to be distribution transformers.
I am guessing because of three phase (delta) load. Pull one phase and you have dropped 42% of the available kva, but your load becomes open delta. Pulling the second cutout drops the other 58% of your load. The third phase is just magnetizing currents in your transformers.
@kelljm Thank you, kelljm. I don't understand "just magnetizing currents in the transformers." Reverse emf from collapse of magnetic field in the third transformer?
I need to see a schematic. I forgot difference betwee Y and /.\
On a wye bank, Each phase of primary goes into its own coil which ultimately leads to ground. This is why there is "ground potential" in wye systems. Delta banks derive power from between the phases..in other words, each of the three coils is hooked to two primary phases.
Magnetizing currents are simply the load created by energizing coils (thus a relatively small arc to break).
Very cool video, we did that at college for practice, first with no load and then with load, it was really cool. We replaced the fuses inside the switches and put them back into position. It is not only obvious to switch the power off with insulation but with very high dielectric strength insulators (many KV or so), so you can do it safely.
That looks like a pole disconnect switch. I think it disconnects the high voltage power to de-energize a power pole. He's using a long insulated handle to turn off a switch on the pole. I've seen the switches on distribution lines before, but I've never seen anyone actually turn them off before. That would be pretty cool to see. The lines are live, so when they disconnect the switches, it arcs.
We were taught to open single phase switchgear in A-C-B sequence, not A-B-C as shown in the Video. This lessens the chance of the 2nd Isolator (which draws the biggest arc) arcing across to a live phase causing a phase to phase fault which could take the feeder out, not to mention causing an explosion and damaging the hardware.
Eastmunda 1 year ago
the last fuse looked toasted. So it would already open cct so no arc.
Cjudd001 1 year ago
ahhahaa lool..duck:D
OnnomonnomonnO 2 years ago
мне послышалось или он по руски быстро сказал "давай!";)) Тогда откуда такой клас напруги?
ftynmik 2 years ago
why no loadbuster?
TheBingojim 2 years ago 2
Cute compared to a sub station switch. O_O
FelixTheHouseFreak 2 years ago 2
lol they farted
Zachary77F 2 years ago 2
Hey, look, the third one is broken, lol!
Syphosium 2 years ago
yeah,it really sounded like Flatulence!,LOL!
form109 3 years ago 2
HE HE....... it farted!!!
geeklord09 3 years ago 7
idiot
Narcotiik 3 years ago
WHOAAA!!
Valonaren 3 years ago 2
thats the normal way to disconnect its dangerous to get close arching can happen since its live and has a load.
jtreign9097 3 years ago 4
the bad thing is when the arc is formed on you :)
r0nd0m 3 years ago 2
@jtreign9097 Thats what she said?
FadeDown 1 year ago
I've never saw switching done manually. It's kind of cool.
Jimmy146 3 years ago 2
dont know about america (im assumeing this is usa as we dont have these on 33kv in blighty) but our rods are tested yearly to 75 kva per inch, so as long as your nuts are big enough, no worrys!
drumingmatt 3 years ago
anybody knows if there is a specific reason why the last disconnector did not have a big acr like the rest? Less load? Better maintenance? just curious...
Arkthurius 4 years ago
Hard to say what kind of a trans bank that line is feeding but if it is an open delta the second cutout usually arcs more than the first cutout. Can't explain the theory thats just the way it is . I think someone told "phase resonance or the like of that.
joetoorivers 3 years ago
I re-read your question the second cutout was likely connected via the windings of the B pase transformer to the third cutout. when the second cutout is opened it is braking a phase to phase condition. When the third is opened it is just droppping potential of the transformer windings.
joetoorivers 3 years ago
Sort of makes sence but i will still do some research...
Arkthurius 3 years ago
The arc is produced when opening the links on a 70 kilometre line. There is nothing at all connectecd to the line. The arc is capacitance / inductance.
B342345415 3 years ago
Load, either reactive or capacitive, is related to the arcs that form when you disconect this loads. This is just why you have to turn off the load of a transformer when you are going to move the voltage regulator tap. In the circuit of the video, by the position of the fuses it seems that the cables on the right are the feeders and the left ones go to load, which is likely to be distribution transformers.
Arkthurius 2 years ago
@B342345415 Appears to be a typical three-phase circuit.
Why no arc opening the last switch?
Thank you.
robertgift 1 year ago
@robertgift
I am guessing because of three phase (delta) load. Pull one phase and you have dropped 42% of the available kva, but your load becomes open delta. Pulling the second cutout drops the other 58% of your load. The third phase is just magnetizing currents in your transformers.
kelljm 1 year ago
@kelljm Thank you, kelljm. I don't understand "just magnetizing currents in the transformers." Reverse emf from collapse of magnetic field in the third transformer?
I need to see a schematic. I forgot difference betwee Y and /.\
robertgift 1 year ago
@robertgift
On a wye bank, Each phase of primary goes into its own coil which ultimately leads to ground. This is why there is "ground potential" in wye systems. Delta banks derive power from between the phases..in other words, each of the three coils is hooked to two primary phases.
Magnetizing currents are simply the load created by energizing coils (thus a relatively small arc to break).
kelljm 1 year ago
Your company never heard of a load buster?
joetoorivers 4 years ago
what exactly is a load buster???
codemsan 3 years ago
Very cool video, we did that at college for practice, first with no load and then with load, it was really cool. We replaced the fuses inside the switches and put them back into position. It is not only obvious to switch the power off with insulation but with very high dielectric strength insulators (many KV or so), so you can do it safely.
Arkthurius 4 years ago
sounds like a electric fart
Tornento 4 years ago
opening a switch under no load?? 33kv will still arc a bit..
sme107 4 years ago 2
Three words for you.. Load Break Tool. Don't wanna get something started up there, do you?
urbanxer 4 years ago
What does that do???
Bretty135 4 years ago
That looks like a pole disconnect switch. I think it disconnects the high voltage power to de-energize a power pole. He's using a long insulated handle to turn off a switch on the pole. I've seen the switches on distribution lines before, but I've never seen anyone actually turn them off before. That would be pretty cool to see. The lines are live, so when they disconnect the switches, it arcs.
ct92404 4 years ago
not huge, but still good. thanks :-)
johnofe 4 years ago