If a wye-delta transformer has a turns ratio of 2:1 and a secondary line voltage of 480 V, what is the secondary phase current?

To determine the secondary phase current of a wye-delta transformer given a turns ratio and secondary line voltage, it’s necessary to understand the relationship between line voltage, phase voltage, and current.

In a wye connection, the line voltage ((V_L)) is related to the phase voltage ((V_P)) by the equation:

[ V_L = \sqrt{3} \times V_P ]

Given that the secondary line voltage is 480 V, we can find the secondary phase voltage ((V_P)) by rearranging the equation:

[ V_P = \frac{V_L}{\sqrt{3}} ]

[ V_P = \frac{480 V}{\sqrt{3}} \approx 277.13 V ]

Now, with a turns ratio of 2:1, we can imply that the primary phase voltage would be twice that of the secondary phase voltage if considering a step-down configuration for the currents. However, since the current transforms inversely with the turns ratio, one needs to account for this relationship when evaluating phase currents.

The phase current in a wye connection ((I_P)) can be calculated using the equation for the secondary side:

[ I_P = \