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Phase and Line current in 3 phase circuits

  • #1
295
4

Homework Statement


upload_2017-10-30_13-2-55.png

I need to first find phase current in the load and line current from the supply


Homework Equations




The Attempt at a Solution


upload_2017-10-30_13-9-8.png

I thought it would be easier to work with a star because then the Ztl would be in series with it... I am not sure how to find the current but my best guess was using this power equation. For the second current, I am not sure how to proceed.
 

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Answers and Replies

  • #2
cnh1995
Homework Helper
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You don't need to convert it in star. Keep it as it is and find the line current from the power equation.

Your attempt is unclear.
What is the active power input to the motor?
 
  • #3
295
4
You don't need to convert it in star. Keep it as it is and find the line current from the power equation.

Your attempt is unclear.
What is the active power input to the motor?
Can I use the same power equation that I had used ?

I guess the power input is 74600 W
 
  • #4
cnh1995
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Can I use the same power equation that I had used
Yes.
I guess the power input is 74600 W
What about efficiency?
 
  • #5
295
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Yes.

What about efficiency?
If it is only 90% then only 67140 W. I use this as P.

WIll V be 240/sqrt(3)
 
  • #6
cnh1995
Homework Helper
Gold Member
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If it is only 90% then only 67140 W. I use this as P.
How can the input be less than the output? Use the efficiency correctly.
WIll V be 240/sqrt(3)
No.
 

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