How does the high side line current compare to the coil current in a wye bank?

In a wye (Y) configuration of a transformer bank, the relationship between line current and coil (phase) current is critical to understand. In a wye configuration, the currents at the line side (the high side) are directly related to the currents in the coil.

The line current in a wye system is equal to the coil current due to the nature of how these currents interact. Since each line connects to a separate phase of the transformer, the current flowing through each phase coil is the same as the current flowing through the connected lines. This is a fundamental principle of three-phase power systems; in a balanced system, each phase carries the same amount of current, and thus, the line currents match the phase currents.

Additionally, in a three-phase system, the line currents are consistent with the phase currents, and this configuration does not create any transformation ratio that would change their relationship. Therefore, the correct conclusion is that the high side line current is indeed the same as the coil current in a wye bank configuration. Understanding this relationship is essential for performing calculations related to power distribution and transformer operations.