hello !
there are two wayes to calculate the PF.
the original definition is that the PF is the angle between the current through and the voltage on a consumer (electrical machine-not DC - , lamp atc...) - cos(fi).
the second way is to calculate the power factor by measuring the active power(P) and the reactive power [Q] (or the imaginary power S = V * I ) and use the formula PF = P/S. or by measuring the related enrgies.
this way of computing the PF used in calculating the consumer PF (at the main board ).
if there are harmonics in the sysyem then PF not equel cos(fi).
for en individual electrical equipment it is the same pf=cos(fi)
yours,
moti bohadana
