# What can cause all the lights on a circuit to fry?



## henderson14 (Oct 23, 2010)

I'm thinking a short, but how does it happen? I've seen it happen a couple of times when a whole lighting circuit is fried after powering up costing a lot of money. It happened today on my job where my foreman said it would cost 30k and one JW thinks he will get laid off because of it. All the lights need to be replaced and there are a lot on the circuit because they are LED. I just don't want to ever make this mistake myself.


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## wildleg (Apr 12, 2009)

wiring wrong voltage to a ballast that can't handle it can fry most/all the ballasts on that circuit, especially if they are electronic.


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## 480sparky (Sep 20, 2007)

Some doofus opened the neutral of a MWBC whilst energized.


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## MTW (Aug 28, 2013)

Getting 277 and 120 volts confused is a possible culprit.


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## Dennis Alwon (May 9, 2009)

Lots of reasons. Members have given you a few answers and I will add that a high leg on a delta system will do it also.


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## dmxtothemax (Jun 15, 2010)

Most likely too much voltage !
As for specifics as to how it happened ?
You will need to tell us much more.
What type of system ?
What voltages ?
Who did what ?
And where ?

Right royal screw up by the way !
But don't feel too bad
Many others have done stupid things too.

Its how you learn !


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## henderson14 (Oct 23, 2010)

dmxtothemax said:


> Most likely too much voltage !
> As for specifics as to how it happened ?
> You will need to tell us much more.
> What type of system ?
> ...


 I believe it is a 220v lighting system. I don't know a lot of details because I didn't pull and splice it. I think whatever happened happened in the splices in the lights. I think it was probably terminated correct in the panel.


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## ce2two (Oct 4, 2008)

henderson14 said:


> I'm thinking a short, but how does it happen? I've seen it happen a couple of times when a whole lighting circuit is fried after powering up costing a lot of money. It happened today on my job where my foreman said it would cost 30k and one JW thinks he will get laid off because of it. All the lights need to be replaced and there are a lot on the circuit because they are LED. I just don't want to ever make this mistake myself.


You didn't put 120v. lights on a high leg, i hope..


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## ponyboy (Nov 18, 2012)

Cheap lights + ground fault


Sent from my iPad using Tapatalk


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## triden (Jun 13, 2012)

I bought a house with the neutral and hot reversed in a branch circuit once. Fried all the CFL's before I fixed it.


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## Southeast Power (Jan 18, 2009)

triden said:


> I bought a house with the neutral and hot reversed in a branch circuit once. Fried all the CFL's before I fixed it.


How would the CFLs know?


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## Southeast Power (Jan 18, 2009)

henderson14 said:


> I'm thinking a short, but how does it happen? I've seen it happen a couple of times when a whole lighting circuit is fried after powering up costing a lot of money. It happened today on my job where my foreman said it would cost 30k and one JW thinks he will get laid off because of it. All the lights need to be replaced and there are a lot on the circuit because they are LED. I just don't want to ever make this mistake myself.


Ok so,
You are in Chicago. This means that they were piped in.
I can only see two problems here.
One could be that everyone on the job missed that the drivers were 120 volt or 120/277 volt.
If they were dual voltage then somehow, only if they used a MWBC, someone had a problem with a neutral somewhere. I can find a few holes in this theory so, don't hang on to it.
What you have to do is find the problem, correct it and then call out the lighting rep.
Then, make them pay for the labor to replace them.
Some holes in that idea too.


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## 99cents (Aug 20, 2012)

Check the driver/ballast voltage before installing. Don't trust the label on the box. I've seen it happen where the fixture inside the box was wrong.


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## MDShunk (Jan 7, 2007)

When I fry, I used to use vegetable oil. In recent years, I try a light coating of olive oil instead.


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## triden (Jun 13, 2012)

jrannis said:


> How would the CFLs know?


Because they contain a triac trigger circuit that must have the correct pin referenced to neutral otherwise it won't trigger properly. It also usually ends up blowing up the traic in most cases.


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## telsa (May 22, 2015)

Open neutrals are destructive to electronic ballasts -- but they usually don't let the smoke out in a flash. Instead, they are prone to struggling along -- trying to do their 'thing' -- and roast themselves in the process.

So it's relevant as to how long the circuit was energized -- and how quickly the units were fried.

Severe over-voltage usually smokes 'em in no time at all. That's mighty uncommon, though.

It's possible for electronic ballasts to fire right up -- with an open neutral -- and seem perfectly okay -- IF and only IF -- the neutral return back to the panel is mighty long and the break in the path occurs after quite a run.

I've only witnessed that (freak) behavior once. (277 VAC L-N loads) In this particular case, the electronic ballasts DID NOT SMOKE. The neutral returns for them ( two parallel "B" phase circuits ) were ~ 80 meters long -- to reach the break in the path. (doofus make-up by an apprentice... he made up both parallel neutrals to each other coming and going. Heh )

This bizarre circuit ran perfectly during the shake down period. Six months later, these same light fixtures didn't want to come on. Once the neutrals were corrected, everything fired right back up -- with no damages at all. ( !!!! )

The only physical explanation for that circuit must be that the large mass of copper in EMT was enough of an EM 'sink' to A L M O S T replicate the neutral rail back at the panel. When the weather changed, the impedance of that sink changed enough to cause the electronics to 'kick.'

All in all, pretty amazing. At the time, it had me falling out of my chair. 

1) The doofus mistake

2) That it ran 'normally' for so long 

3) No damage to the electronics (!)


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## ce2two (Oct 4, 2008)

triden said:


> I bought a house with the neutral and hot reversed in a branch circuit once. Fried all the CFL's before I fixed it.


Interesting....


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## Southeast Power (Jan 18, 2009)

telsa said:


> Open neutrals are destructive to electronic ballasts -- but they usually don't let the smoke out in a flash. Instead, they are prone to struggling along -- trying to do their 'thing' -- and roast themselves in the process.
> 
> So it's relevant as to how long the circuit was energized -- and how quickly the units were fried.
> 
> ...


In meters? Really


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## MTW (Aug 28, 2013)

jrannis said:


> In meters? Really


You actually read his posts? :001_huh:


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## Ontario (Sep 9, 2013)

Some guys put instrument transformers in their wallpacks to convert 347V to 120V. It's possible the transformers were wired backwards.


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## RIVETER (Sep 26, 2009)

wildleg said:


> wiring wrong voltage to a ballast that can't handle it can fry most/all the ballasts on that circuit, especially if they are electronic.


Yes, it happens. In 1983 on a major shutdown at Ford a series of power roll tables...about 20 of them, fried the brake coils because they were wired from the factory for a lesser voltage than 480.


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## Vintage Sounds (Oct 23, 2009)

I was on a job where a guy crossed AC and DC splices in an exit sign. Or maybe 6. These were 347v exit signs and the backfeed blew up the battery packs in a rather grand way.


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## RIVETER (Sep 26, 2009)

Vintage Sounds said:


> I was on a job where a guy crossed AC and DC splices in an exit sign. Or maybe 6. These were 347v exit signs and the backfeed blew up the battery packs in a rather grand way.


What was the brand of 347 volt signs?


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## Vintage Sounds (Oct 23, 2009)

RIVETER said:


> What was the brand of 347 volt signs?


I can't remember since this was 4 years ago but I imagine it was Beghelli or Stanpro.


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## Dhender1985 (Jul 26, 2015)

On a job i was working on, I switched the brown and gray by mistake. I was using a crappy flashlight, and they looked almost the same in the light I had. That fried a few ballasts down the line. Another guy on the same job did that on multiple fixtures.


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## fargowires (Aug 26, 2010)

MDShunk said:


> When I fry, I used to use vegetable oil. In recent years, I try a light coating of olive oil instead.


Olive oil has too low a burnining temp. Try peanut oil. Especially for stir fry.


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## fargowires (Aug 26, 2010)

10 years ago (good god, how time flies), my guys were retrofitting a warehouse to T8 highbays, and doing some small electrical clean-up work. They removed an old plywood backerboard from a previous installation, and found some old wiring behind it, that we determined was expendable. What we did not catch was the cheater neutral-to-bonding connection that was among the ancient wires. We cut em, and 'FLASH', out went the new lights. 27 electronic ballasts died instantly. Ouch.


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## pete87 (Oct 22, 2012)

Dhender1985 said:


> On a job i was working on, I switched the brown and gray by mistake. I was using a crappy flashlight, and they looked almost the same in the light I had. That fried a few ballasts down the line. Another guy on the same job did that on multiple fixtures.




On a packed box , just off the floor , hospital demo job for 8 new x-ray machines ...

a blue dose look like a green !




Pete


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## henderson14 (Oct 23, 2010)

Looks like an open neutral was the culprit. It was a 277 circuit and someone left the neutral that was feeding the lights open, so I guess ot turned it into a 480v system.


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## telsa (May 22, 2015)

henderson14 said:


> Looks like an open neutral was the culprit. It was a 277 circuit and someone left the neutral that was feeding the lights open, so I guess ot turned it into a 480v system.


It didn't go to 480 VAC. The neutral was not landed on the other hot phase.

Just being an open neutral -- is sufficient to roast the circuits given enough time -- like even a few hours -- let alone, over night.

There are capacitors aplenty in electronic ballasts. When the neutral is cut, the electrons really get backed up -- frustrated.

Critical voltages swing high:

A capacitor that can't stop eating voltage from 277 VAC will rapidly rise in voltage up towards 277/ 0.707 == ~ 392 Volts -- PEAK of the wave form. 

_RMS notions no longer apply._

Then the complications begin. When a pulse of VAC comes shooting down the conductor -- with nowhere to go -- wave physics dictates that it bounce back -- very much a mirror effect. 

This is very much a magnetic field effect. It's by this mechanism that weird, high voltage transients get generated. The actual energy in these is -- by ordinary standards -- pitifully small. However, eventually these little jolts tunnel through the teeny-tiny dimensions used in electronic circuits -- and let the smoke out.

There's a LOT of variability involved. As reported at #16 miracles can occur. Alternately, the electronics goes poof in just seconds. I've seen both. 

The MOST common failure mode is "lights left burning over night." With this mode, every single dang unit is smoked. 

This mode is also consistent with a dejected journeyman who knows that he'll end up the goat at the end of this rope. 

%%%

The above physics is also why you really want to break BOTH poles when switching a 480 or 208 volt control circuit. While just switching one has long been the practice, the fact is that the coil/ windings are being constantly exposed to one leg of hot power. Even though it's not completing a circuit -- it's reflecting back the energy wave from that hot leg. 

THIS is the source of many a cooked motor/ coil. Even in the off / non-rotating mode, current is left to pulse in and out of its windings. Just on hysteresis alone, it can't really cool down. 

[ Changing the magnetic polarity of the iron core of the windings will absorb energy, release heat, even in an uncompleted circuit. ]

The circuit may appear to be totally squared away -- but it's destined to bleed energy and have a shorter service life. 

The physics of wave energy are not in conventional course materials. And the math is super complicated: upper division college material... just brutal. :blink:

You'd have to read Feynman's Lectures on Physics etc. to come across these 'field effects.' { as in "B" field effects }


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## pete87 (Oct 22, 2012)

Telsa ... I am sure glad that you explained all that .





Pete


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## MTW (Aug 28, 2013)

telsa said:


> It didn't go to 480 VAC. The neutral was not landed on the other hot phase.
> 
> Just being an open neutral -- is sufficient to roast the circuits given enough time -- like even a few hours -- let alone, over night.
> 
> ...


What you just posted is complete and utter nonsense. An open neutral instantly destroys electronics because of over voltage, not capacitors and the rest of the nonsense you mentioned.

A capacitor will not "eat voltage" in an open circuit. I could go on, but what you posted is so ridiculous and wrong it's a waste of time.


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## telsa (May 22, 2015)

MTW said:


> What you just posted is complete and utter nonsense. An open neutral instantly destroys electronics because of over voltage, not capacitors and the rest of the nonsense you mentioned.
> 
> A capacitor will not "eat voltage" in an open circuit. I could go on, but what you posted is so ridiculous and wrong it's a waste of time.


You obviously never took college level Physics.

So sad.

Do NOT comment further until you have done so.

Entire texts have been written up on the effects cited. Sheesh.

Going from 0 (commutation) to 277 (RMS voltage) to 392 (sine wave peak) happens twice EVERY cycle. 

That's the HIGHEST voltage possible from the wave form -- UNTIL you get into wave physics.

Take a deep breath and think about that. 

WHERE is the over-voltage coming from? 

You are limited to 392 PEAK volts... with an open neutral... with your primitive Physics.

For more on B field effects -- wave Physics -- study an upper division text.

You will be humbled. :thumbsup:

BTW, MOST fellas drop out of the course -- it's too mathematically difficult, just not something that an average Joe can comprehend. :no:

Feynman got the Nobel Prize for figuring it all out -- in extreme mathematical detail. At the time he was the ONLY Physicist who could perform the math -- in the world.

Yes, his abilities got a major write up.

AFTER Feynman worked it out, lesser minds could follow in his footsteps.

He has lectures that you can find on YouTube.

Most viewers get a brain fit trying to keep up with him. :thumbsup:

Wave Physics is the ultimate source of all of the "harmonics" you keep reading about. :thumbsup:

Duh! :laughing:


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## MTW (Aug 28, 2013)

telsa said:


> You obviously never took college level Physics.
> 
> So sad.
> 
> ...


Could you please show me a physics text book equation where current flows in an open circuit?


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## henderson14 (Oct 23, 2010)

telsa said:


> It didn't go to 480 VAC. The neutral was not landed on the other hot phase.
> 
> Just being an open neutral -- is sufficient to roast the circuits given enough time -- like even a few hours -- let alone, over night.
> 
> ...


The difference between 480 and 277 is a neutral. The neutral is never landed on "the other hot phase." The open neutral fried the lights instantly, not "given enough time" or "overnight" because it was instantly turned into a 480 circuit. Hence the small explosion as evidence.

Also. "There are capacitors aplenty in electronic ballasts. When the neutral is cut, the electrons really get backed up"
-120v circuits don't even light up with a cut neutral, so electrons don't get backed up.


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## Fibes (Feb 18, 2010)

MTW said:


> Could you please show me a physics text book equation where current flows in an open circuit?


I would like to see that too.


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## MTW (Aug 28, 2013)

Alright, I get it. We're being trolled. I'm going back to ignoring his postings again.


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## Meadow (Jan 14, 2011)

MTW said:


> Alright, I get it. We're being trolled. I'm going back to ignoring his postings again.



I know you and I have not been on the best terms however I will take your side on this issue since I always speak my mind. I have been reading a lot of Telsa's (albeit long) posts and the vast majority are filled with half truths or flat out incorrect information. If anything I get the feeling he is trying to make fun of me or Chicken Steve.


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## Meadow (Jan 14, 2011)

telsa said:


> You obviously never took college level Physics.
> 
> So sad.
> 
> Do NOT comment further until you have done so.



I did. A lot of what you say is incorrect, misleading or obfuscated. You also never come back to admit your wrong when proven wrong.

Wave physics you speak of are more about harmonics and ferroresonance, not the physics behind an open neutral. In so far you throw around words but never the equations or actually getting to the point you were trying to make in the first place.


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## MTW (Aug 28, 2013)

meadow said:


> I know you and I have not been on the best terms however I will take your side on this issue since I always speak my mind. I have been reading a lot of Telsa's (albeit long) posts and the vast majority are filled with half truths or flat out incorrect information. If anything I get the feeling he is trying to make fun of me or Chicken Steve.


I think he's just stark raving mad.


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## Meadow (Jan 14, 2011)

MTW said:


> I think he's just stark raving mad.



That, or just trolling hard :laughing:

I still think he might be an old member with a new name.


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## MTW (Aug 28, 2013)

meadow said:


> That, or just trolling hard :laughing:
> 
> I still think he might be an old member with a new name.



He's trolling and a lunatic, I'm certain of that. Normal people couldn't write the scripts that he does.


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## Meadow (Jan 14, 2011)

MTW said:


> He's trolling and a lunatic, I'm certain of that. Normal people couldn't write the scripts that he does.



Or put effort to take random words out of physics books then string them together :laughing:


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## chicken steve (Mar 22, 2011)

Explain decaying magnetic flux please

~CS~


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## telsa (May 22, 2015)

MTW said:


> Could you please show me a physics text book equation where current flows in an open circuit?


Fellas...

I've told you where to read, who to read, why to read.

At my rate of pay I'm not willing to give you personal lectures that would be inferior to those already up on YouTube given by THE Nobel Laureate who is credited with the total solution of electrodynamics -- fusing Maxwell's equations with Quantum Physics.

Yapping away about your -- shameful -- embarrassing -- shameless ignorance -- 

Well, the Internet has a deep memory.

It's PLAIN that none of you fellas has EVER spend a day in upper division Physics.

....

Solid state switching circuits are entirely outside the primitive circuit discussions given to high school students and trade school apprentices.

Factors -- real world factors -- that dominate at such frequencies are NEVER brought up with the mentally challenged. :no:

They are not even brought up in most lower division Physics courses.

Many of these discoveries, circuits, etc. are so new that patents are still being issued. 

I have not invented ANYTHING for you fellas.

EVERYTHING I've posted comes from the world of quantum mechanics -- and wave physics. Many off these effects were not resolved until AFTER WWII.

They were ENTIRELY omitted from your texts, schooling and all discussions.

We will have to stop here. 

As for my own contributions... if the above is stressful ... and we know it must be ... we'd best stop. 

When you can't bear to google, read, study and think... it is pointless to give you references and links.

So I let other readers be ware. You can conduct your own studies and -- if smart -- diligent -- come to know and laugh with me about the self-shaming posters. :laughing:

%%%

For those too young to know the first thing about quantum physics: many of the normal rules of life are turned entirely upside down in the world of the fantastically small. It took the best brains on the planet -- DECADES -- to dope them out.

Discoveries are still being made. The search for all of the fundamental particles is still very much under way. :thumbsup:

https://www.youtube.com/watch?v=grmuFkCdz3s


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## telsa (May 22, 2015)

Lastly, the basic circuits taught to electricians can't explain why solid state circuits work at all. :no:

Yet the light bulb does not go 'on.' :laughing:


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## MTW (Aug 28, 2013)

Lol.


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## OaklandElec (Jan 4, 2011)

telsa said:


> Fellas...
> 
> I've told you where to read, who to read, why to read.
> 
> ...


Awesome.


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## chicken steve (Mar 22, 2011)

explain Tesla's Dark Energy ....

~CS~


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## MTW (Aug 28, 2013)

Silly me, quantum mechanics say that current can flow in an open circuit. Awesome, we don't need switches anymore, just a quantum device to stop the flow of electricity. :thumbup:


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## henderson14 (Oct 23, 2010)

telsa said:


> Fellas...
> 
> I've told you where to read, who to read, why to read.
> 
> ...



You're a weird guy. What does dark matter and quantum physics have to do with lights blowing up.


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## MTW (Aug 28, 2013)

I gotta hand it to this troll, this is the first time I've ever heard wave mechanics used to explain open neutral behavior. :laughing:


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## Meadow (Jan 14, 2011)

Pure Awesome! :laughing::laughing:


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## Meadow (Jan 14, 2011)

MTW said:


> Silly me, quantum mechanics say that current can flow in an open circuit. Awesome, we don't need switches anymore, just a quantum device to stop the flow of electricity. :thumbup:



Dont you get it, they just go into another dimension!?!?!?  The universe is so massive being nearly infinite that given a finite amount of matter and energy in an infinite amount of time results in every scenario that could possible occur playing out at some point in space-time. When two identical events play out at any moment in space-time their matter is inexplicably interconnected bridging space-time fabric in an effort to reach equilibrium, a kind of cosmic whole. Thus, electrons will travel to a different dimension, which is simply the same events playing out at different points in the cosmos at different times and space across the 3 dimensional spectrum we perceive to be linear. 

Observing an object can change the quantifiable measurability of this outcome since our perception of conscious is a projection from the universe itself trying to reach a finite state. Remember, traveling near or at the speed of light results going going forward in time, and going faster then the speed of light means you are traveling back in time.


Common dude! I was taught this in the first grade, sheesh! :no:


(btw, on a serious note semiconductor were influenced by quantum theory)


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## daks (Jan 16, 2013)

As a person that has some fancy diplomas and degrees, that could allow me to put fancy letters after my name on cards... but don't. Physics was one of them.

As a person that is now an electrician...

And as a person that follows some of the different quantum theory developments that are being researched and how they affect the standard physics model.

I feel after reading your posts in this thread telsa,

I am more than qualified to say... WTF was that! Sorry but waaaay off. 

I however am not qualified to diagnose if it was hallucinogens, alcohol, psychosis or trolling that caused whatever that explanation was. 

Think of the lighting circuit as a MWBC,
draw in out,
think it over,
then cut the circuit's grounded conductor (incorrectly refereed to as a neutral). 
What is the new current path?
What is the new potential (V) in that new current path? 

You don't need higher math for this one, I have confidence in your ability to use the crayon and paper to work this one out.

And if you're going to jump on a high horse and flout arrogance and knowledge at these guys, please at least be in the ballpark. Reminds me of "The Emperor's new Clothes"


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## RIVETER (Sep 26, 2009)

daks said:


> As a person that has some fancy diplomas .
> then cut the circuit's grounded conductor (incorrectly refereed to as a neutral).


Apparently credentials don't tell the whole story.


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## daks (Jan 16, 2013)

RIVETER said:


> Apparently credentials don't tell the whole story.


 Lol well it's hard to type when you're laughing, but English was never one of my majors anyways. :thumbup:


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## Spark Master (Jul 3, 2012)

You can use a capacitor to create the 3 phase for a 3 phase motor, when you only have 2 legs feeding the motor. The capacitor will shift the current 90 degrees.


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## RIVETER (Sep 26, 2009)

daks said:


> Lol well it's hard to type when you're laughing, but English was never one of my majors anyways. :thumbup:


Okay...my bad. I forgot you speak Canadian.:thumbsup:


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## RIVETER (Sep 26, 2009)

telsa said:


> You obviously never took college level Physics.
> 
> So sad.
> 
> ...


I like the way you write. All of the words are spelled correctly.


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