Question

Is it necessary to use two wattmeters to measure the power of this circuit? Why or why not?

Answer 1

Explanation:

The total power in a Three wattmeter method of power measurement is given by the algebraic sum of the readings of Three wattmeters. i.e. Except for 3 phase, 4 wire unbalanced load, 3 phase power can be measured by using only Two Wattmeter Method.

Answer 2

Answer:

Two Wattmeter Method can be employed to measure the power in a 3 phase, three wire star or delta connected the balanced or unbalanced load. ... The total instantaneous power absorbed by the three loads Z1, Z2 and Z3, are equal to the sum of the powers measured by the Two wattmeters