Question

1. A 480 V (rms) source supplies power to two loads connected in parallel. The first load draws 80 kW and 30 kVAR. The second load draws 100 kVA at a power factor of 0.6 lagging. a) Draw the power triangle for the first load and determine its power factor; b) Determine the current (both magnitude and phase, using the source voltage as the phase reference) drawn by the first load; c) Draw the power triangle for the second load and determine the real and reactive power it absorbs; d) Determine the current (both magnitude and phase, using the source voltage as the phase reference) drawn by the second load; e) Determine the total current drawn by the two loads, both magnitude and phase; f) Draw the phasor diagrams showing i) the voltage and current drawn by the first load, ii) the voltage and current drawn by the second load, and ii) the voltage and total current; from these phasor diagrams, determine the power factors for the first load, the second load, and the total load (note that you already know two of these answers); g) Draw the power triangle for the combined loads and determine the power factor seen by the source.

Answer 1