The total real power of a threephase load is measured by two

The total real power of a three-phase load is measured by two-wattmeter method such as illustrated In the diagram below:

Solution

i) Total Real power,P = P1+P2 = -80+127 = 47 W

ii) Total Reactive power,Q = P1-P2 = -80-127 = -207 VAR

iii) Total Apparant power,S = sqrt(P^2+Q^2) = sqrt((47^2+(-207)^2) = 212.26 VA

iv) power factor,PF = P/S = 47/212.26 = 0.22