A 75-kVA, 230/115-V, 60-Hz transformer was tested with these results:
• Open-circuit test: 115 V, 16.3 A, 750 W
• Short-circuit test: 9.5 V, 326 A, 1200 W
Determine:
(a) The equivalent impedance in high-voltage terms.
(b) The voltage regulation at rated load, 0.8 power factor lagging.
(c) The efficiency at rated load, 0.8 power factor lagging, and at half-load, unity power factor.
(d) The maximum efficiency and the current at which it occurs.