Power factor in unbalanced 3phase system
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KatyLied P.E.
The Alchemist.
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."
KatyLied P.E.
The Alchemist.
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.
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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I hope minor details such as these aren't necessary on the test. Seeing how this is something that simply said in passing.
KatyLied P.E.
The Alchemist.
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".
KatyLied P.E.
The Alchemist.
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.
so belly button is a no no? no pubic area was shown what so ever
i'm good tho. its not important
ptatohed
Licenced to Spell
Dude, with all due respect, it was disturbing.
The Wizard
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ptatohed
Licenced to Spell
Correct, I hate looking at half naked dudes. 
Audi Driver P.E.
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This from the guy who said the PE was so easy.
