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Novanian

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Good Evening,

I have just begun my studies for the Power PE and I just purchased the book by Graffeo.

However, I did notice quite a few people mentioning several key topics that were missing. I was wondering if any of you have found resources to use as reference / studying for these other topics.

  • Voltage changes when a transformer is used at a different frequency than designed for
  • MVA ratings of transformer with different cooling ,OA, FA, FOA, which one to pick for calculations
  • Harmonics and how to decrease them ( 5th,7th,11th,...)
  • how to control KW with frequency/speed of driver and control voltage with KVAR
  • Relationship of voltage rise with kvar added and short circuit duty
  • UL standards
  • Effect of field excitation on motor speed
Any study resources or materials that cover some of these topics would be appreciated!

If you do have some, could you quote which bullet point specifically the resource you linked applies to?

Thanks!

 
this topic has been covered ad nauseam in the various threads. A little searching will yield more topics than needed as far as study material. 

 
45 minutes ago, Ken PE 3.0 said: this topic has been covered ad nauseam in the various threads. A little searching will yield more topics than needed as far as study material. 
I'm not convinced any of these things have ever been discussed ;-)
Well, there definitely isn't a one stop shop for material. But I stand by original statement.

 
Doubt you'd need half of the topics you listed and Graffeo covers most of that, just not explicitly indicated.  As far as OA etc., you would most definitely be given the explicit parameter to use in which to solve.  At that point, use the ad nauseam power/voltage/current relationships to solve at that rating.  Unless, of course, you're unfamiliar with what OA, OFAF, etc. are?  Best place to start is to look at the topics given by NCEES before each exam administration, and then start dissecting how you plan to study (hint: understand theory just as much or more than crunching numbers through calculations).  Don't waste time on things that aren't listed.  Also, remember that this exam allots 6 minutes per problem... Use a little common sense in your preparation.  If it takes you more than 6 minutes to work any problem in the NCEES practice exam, you need to brush up on your skills.  It will be a fair test if you're prepared; however, if you're not prepared, you will be done with for the day by time lunch break hits.  Good luck!

 
@cupojoe PE PMP and @Ken PE 3.0

Thanks for the input and suggestions!

I was able to find more specific information about one of the topics previously mentioned, here in these forums:

This thread and its attached PDF helped for the Transformer Ratings:







Doubt you'd need half of the topics you listed and Graffeo covers most of that, just not explicitly indicated.  As far as OA etc., you would most definitely be given the explicit parameter to use in which to solve.  At that point, use the ad nauseam power/voltage/current relationships to solve at that rating.  Unless, of course, you're unfamiliar with what OA, OFAF, etc. are?  Best place to start is to look at the topics given by NCEES before each exam administration, and then start dissecting how you plan to study (hint: understand theory just as much or more than crunching numbers through calculations).  Don't waste time on things that aren't listed.  Also, remember that this exam allots 6 minutes per problem... Use a little common sense in your preparation.  If it takes you more than 6 minutes to work any problem in the NCEES practice exam, you need to brush up on your skills.  It will be a fair test if you're prepared; however, if you're not prepared, you will be done with for the day by time lunch break hits.  Good luck!
Thanks for the advice TNPE, I will take that into consideration. Since this will be my first time attempting I wanted to be sure to learn more about some of the topics above. Also some of the items I do encounter occasionally in the workforce so its always great to get more understanding about them as well as I do not directly deal with most of them.

Regardless, I appreciate the guidance! 

 
The best advice I can give with regards to frequency/voltage relationships and derating is:

Some devices, in reality, have some inherent tolerance, hence, you notice various components rated at 50/60 Hz.  That said, if you increase the frequency, the V/Hz relationship will always decrease with a constant voltage (which is good..you aren't overloading with current, heat, etc.).  Put it another way, reactance (X) for an inductor is jwl (w=omega), and for all practical purposes for a transfomer/motor winding, inductive reactance dominates resistance, at least for these type of examples.... Which yields:

V=IZ (where Z=X=jwl)...lower X yields higher current, which you don't want with regards to questions pertaining to V/Hz relationships.

 
One point that seems to be overlooked is the help you can receive by Googling and searching YouTube .Sometimes you have to dig a bit but doing that helped me out tremendously.  I was able to print out info and add to my three ring binder.  This is coming from someone who first took the PE 18 years ago and, when I passed it 2-1/2 years ago, realized how much easier things would have been if the internet had been as thorough as it is now.  Plus, sometimes you can find an explanation that helps you more than one you had already gotten out of a book.  Different people learn different ways. 

 

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