Reference no: EM131035054
A three-phase grounded wye-delta connected transformer supplies a load. The load voltage is 480 V (line-to-line), the loads are:
Phase AB is 25 kW with power factor 0.8 lagging;
Phase BC is 10 kVA with power factor 0.75 lagging; and
Phase CA is 47 kW with power factor 0.85 lagging.
The transformer is rated 50 kVA, 12.47 kV / 480 V, 9.2%. Calculate:
(a) the unbalanced delta currents in each phase (IAB, IBC, ICA)
(b) the unbalanced wye currents (Ia, Ib, Ic)
(c) the required supply voltages per phase (both line-to-line and line-to-neutral)
(d) the ground current at the wye side. Hint: place the transformer impedance at the wye side in series in each phase.