Q. A 5-kVA, 480:120-V, two-winding, 60-Hz, single-phase transformer has an efficiency of 95% while delivering rated load at rated voltage and 0.8 power factor lagging. This transformer is to be connected as an autotransformer to step down a 600-V source to 480 V.
(a) Draw a schematic connection diagram as an autotransformer.
(b) Find the maximum kVA rating as an auto- transformer.
(c) Compute the efficiency as an autotrans- former delivering its rated kVA at 480 V and 0.8 power factor lagging.