# how do i go about finding power factor and kva for questions like these

#### Rance

Joined Mar 26, 2016
2
Im not sure how to get the answer for this question and cant find anything that helps. Any help would be apprecitied.

#### WBahn

Joined Mar 31, 2012
26,398
This is Homework Help, not Homework Done For You. You need to show YOUR best attempt at a solution. That gives us a starting point from which to help you identify where you are going wrong and help guide you toward the answer.

Hint: Just tabulate the real and reactive powers, add them up, and convert to apparent power and power factor.

#### Rance

Joined Mar 26, 2016
2
not sure how to go about this problem this is what i have tried don't know where im going wrong
real power = kva x pf
so i did 100kva x .9pf =90kw for the induction motor being added
and 400kva x .75pf =300kw
new kva is 100kw / .9 = 111.1kva + 400kva = 511.1kva
then 390kw / 500kva = .78 new power factor

#### WBahn

Joined Mar 31, 2012
26,398
Note that the additional motor, in either case, is NOT 100 kVA -- it is 100 kW. They are giving you the real power load of the motor along with it's power factor.

#### WBahn

Joined Mar 31, 2012
26,398
Also, note that you can't add kVA values together because kVA is apparent power that makes no allowance for phase angle.