# Power factor in unbalanced 3phase system



## Phatso86 (Sep 7, 2016)

is the power factor in each phase potentially difference if the system is unbalanced?


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## KatyLied P.E. (Sep 7, 2016)

Power factor is usually thought of in the context of a balanced system.  per The Standard handbook for Elec. Engineers (10th Edition), section 3-76 "The power factor of a polyphase circuit which is balanced is the same as that of the individual phases.  When the phases are not balanced, the true power factor is indeterminate."


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## KatyLied P.E. (Sep 7, 2016)

I have attached a file which includes power factor info as you scroll towards the bottom.

View attachment Power Formulas.pdf


As you look at the beer analogy you can see how if you have more foam (reactive power/i.e. lower pactor factor) you have to use a larger glass (more expensive, higher capacity equipment) but still get the same amount of beer (real power).  More money spent but you get the same amount of work.


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## Phatso86 (Sep 7, 2016)

KatyLied P.E. said:


> Power factor is usually thought of in the context of a balanced system.  per The Standard handbook for Elec. Engineers (10th Edition), section 3-76 "The power factor of a polyphase circuit which is balanced is the same as that of the individual phases.  When the phases are not balanced, the true power factor is indeterminate."


I hope minor details such as these aren't necessary on the test. Seeing how this is something that simply said in passing.


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## Phatso86 (Sep 7, 2016)

KatyLied P.E. said:


> I have attached a file which includes power factor info as you scroll towards the bottom.
> 
> View attachment 8586


thanks for that. pretty useful little tips


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## KatyLied P.E. (Sep 7, 2016)

I personally have never seen any review material that asks about power factor in an unbalanced system.  if you do one of the answer choices would probably be "indeterminate".


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## KatyLied P.E. (Sep 7, 2016)

Having said that, in the real world, we have unbalanced systems all over.  Particularly on electric utility distribution grids.  We do our best to balance and assume  that any power factor "errors" are negligible.


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## Phatso86 (Sep 7, 2016)

looks like moderators removed my photo

I guess looking good on here is a no-no


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## Road Guy (Sep 7, 2016)

If you could crop it above the navel we would appreciate it....


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## Phatso86 (Sep 7, 2016)

Road Guy said:


> If you could crop it above the navel we would appreciate it....


so belly button is a no no? no pubic area was shown what so ever

i'm good tho. its not important


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## Road Guy (Sep 7, 2016)

there's only like 4 females here anyways...


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## Phatso86 (Sep 8, 2016)

Road Guy said:


> there's only like 4 females here anyways...


lol


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## ptatohed (Sep 8, 2016)

Dude, with all due respect, it was disturbing.


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## The Wizard (Sep 8, 2016)

Phatso86 said:


> looks like moderators removed my photo
> 
> I guess looking good on here is a no-no


http://lmgtfy.com/?q=show+off+my+body+forum


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## Phatso86 (Sep 8, 2016)

View attachment 8588


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## ptatohed (Oct 1, 2016)

Correct, I hate looking at half naked dudes.


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## Audi Driver P.E. (Oct 3, 2016)

This from the guy who said the PE was so easy.


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## Phatso86 (Oct 6, 2016)

Audi driver said:


> This from the guy who said the PE was so easy.


the civil definitely was


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