An automatic automotive spray painting system consists of conveyors, spraying, dust
and overspray extraction fans with electrostatic and water walls, finishing with baking
ovens. This system is connected to a 415V, 50 Hz three phase and has been divided into three balanced loads, as follows:
LOAD 1 (STAR): 15 kVA at a power factor of 0.60 lagging;
LOAD 2 (DELTA): 24 kW at a power factor of 0.55 lagging;
LOAD 3 (DELTA): ZRW = ZWB = ZBR = Unknown impedance, but components are known to be balanced.
The system draws a total apparent power of 44kVA at a power factor of 0.82 lagging from the supply.
Determine:
(i) the STAR capacitance required to correct the overall supply Power Factor to 0.87 lagging.
(ii) The total line current drawn from the supply before power factor correction and after.
(iii) LOAD 3 apparent power.
(iv) LOAD 3 impedances ZRW = ZWB = ZBR.