NCEES 531 Power

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brandzimm

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Please help! I have read all of the previous forums on this question. I understand the solution NCEES has but I want to know why the solution I have does not work (see attachment). Its keep me up day and night. I'm taking the Power Exam in Columbia, SC 10/24 so the faster the help the better. I have used several different reference manuals and I am just not getting why MY solution does not work. Thanks in advance! :please:

NCEES 531.pdf

 

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  • NCEES 531.pdf
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Your error is in calculating S1-Phase. You are correct in using S=VI*. However, the "V" you should be using there is the voltage across the impedance which is (-288.67+j288.67). When multiplied by I*, the single phase apparent power lost is 0+j3333 MVAR.

 
Wow. I guess that makes complete sence. I used that Voltage to calculate I. Not sure why I couldn't find this type of solution anywhere but it obviously works. After a minor tweak atleast.

Thank you very much. 1 more week until I can stop working PE problems in my dreams.

 
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