Problem: Three identical single-phase transformers, (with the following specifications: 12 kVA, 120/240 V and 60 Hz) are connected to form a step-up 3-phase Y/? connection. The parameters of each transformer are: R1 = 39.5 mΩ, X1 = 61.5 mΩ, R2 = 133.5 mΩ, X2 = 201 mΩ, RFe = 240 Ω, Xµ = 290 Ω. What are the specifications for nominal voltage, current and power of the three-phase transformer? Determine the line voltages and currents, as well as the performance when the transformer feeds the nominal load at the nominal voltage with a power factor 0.8 lagging.