(1) A 15-kva single-phase transformer designed for [(2,400)/(240)] volts. An open-circuit test on the 240-V winding of the transformer in the figure yielded the following data, corrected for instrument losses: Volts Amperes Watts 580 240 16.75 Calculate the parameters of the core Rc and Xm. (2) The following data were obtained in a short-circuit test of the transformer in the figure, with its low-voltage winding short-circuited. 7 CC () 0.216+/0.443 www Calculate (a) the equivalent primary impedance, (b) the equivalent primary resistance, (c) the equivalent primary reactance. Rc Volts Amperes Watts 63.0 62.5 1660 Thu 0.0021+/0.00454 V - 240 V Xm Equivalent circuit (3) Calculate the approximate value of the primary supply voltage at full load, S= 15 KVA 80 percent power factor (lagging), when the secondary voltage is 240 volts,