In a balanced Y-connected power system calculate the phase voltage E phase if the line voltage E line is 480 volts. Jefferson Electric transformer While three-phase devices are usually the more cost-effective option the single-phase option provides more versatility and can be attractive from a reliability and maintenance standpoint. 13 6 Transformer Calculation Examples Transformers Example Circuit To protect the windings of a transformer against overcurrent use the percentages listed in Table 4503B and its applicable notes. Y transformer calculations . 1-Phase KVA Volts x Amps 1000 1-Phase Amps KVA Volts x 1000 3-Phase KVA Volts x Amps x 1732 1000 3-Phase Amps KVA Volts 1732 x 1000. Wye oh wye would we need a calculator like this. As you can see from the equations above these calculations arent necessarily hard but they are tedious. More important than obtaining the correct answer is for students to explain what they did to get that answer. Transformer connections do not ...