Power factor is the cosine factor of the voltage & current
phase difference. Its a short defination. But if you go
deeply, Power factor=cos@,its depend only on load, instead
of phasewise.if you connect same load in every phase it
will show same power factor value in each phase.Because
power factor is depended upon load resistance=R & its
impedance=Z,

cos@ = R/Z,

So if you are going to calcualte the power factor of all
phase, you have to calculate all resistance & impedance of
the load. Then you can calulate the avg. power factor.

R=R1+R2+R3
Z+Z1+Z2+Z3

(Where Z=R+jXL=Impedance)

cos@=R/Z

Hope my answer will satisfy you.

Best Regards,
Engr.Abdurrahim
shaikh337@rediffmail.com

Dear all,
This is not an answer, actually question.

In one factory, we are dificult to measure resistance,R and
impedance, Z.

What we have is only voltage supply (3phase, 420volt), and
total current flow during maximum usage using clampmeter
(including machinery, lamp, computers, etc...)

We also have info of main transformer step down because it
is in the factory area. Normally they stated value of KVA.

And some factory already install the 'capasitor bank
regulator'

So, how we can calculate the CORRECT VALUE of capasitor
need to install?

I mean, which one is the correct KW, which one is the
correct KVA, and how to calculate existing power factor IF
the factory already have 'capasitor bank regulator'....can
we switsh of the regulator?

What the capacitor Current formula?, For 1 KVAr how amps
its required? for using the KVAr for boosting the PF Design
Calculation.( Eg: for 30 KVAr required how many KW?)