Referring to Problem 4.2.15(b), with a phase voltage as the reference phasor and with a positive phase-sequence supply system, two single-phase watt meters are used to measure the power delivered to the load. The wattmeter current coils are arranged as in Figure 4.3.1 to carry the currents IA and I=, whereas the potential coils share a common connection at the node B. Determine the readings of the two watt meters WA and WC, and verify that the sum of these readings equals the total power in the load.

Problem 4.2.15(b)

(b) Repeat the problem if the three per-phase load impedances of part (a) were connected in delta.