Complex Imaginary Test 3 Problem 57

[BamaBino]

re: Complex Imaginary Test 3 Problem 57

This is a power correction problem on a 3-phase system.

It states: "The rated voltage of the motor is 230V and the full-load current is 60A".

The book's solution has: P=sqrt(3)(230)(60)

But isn't this S ?

Thanks

 

[snerts50]

re: Complex Imaginary Test 3 Problem 57

This is a power correction problem on a 3-phase system.

It states: "The rated voltage of the motor is 230V and the full-load current is 60A".

The book's solution has: P=sqrt(3)(230)(60)

But isn't this S ?

Thanks

Does it mention anything about pf? At unity, S=P and would therefore use the same forumla...then again i dont think you typically operate motors at non unity. I believe i read that somewhere.

 

[Flyer_PE]

The only AC motor that can possibly operate at unity power factor is a synchronous motor. Any induction motor will have a lagging power factor of less than 100%.

 

[vdubEE]

BamaBino,

CI changed the problem statement to read: "A capacitor on a 3-phase system corrects the power factor produced by an induction motor to 0.96 by adding 10.8 kvar. The rated voltage for the motor is 230 V, and the resistive component of the corrected current is 60 A. What was the uncorrected power factor of this inductive load? "

I would suggest trying to get the updates from CI but it looks like they are MIA on email responses lately.