In a 120/240-volt, 3Ø, 4-W open-delta bank of transformers, what does the line current equal?

In a 120/240-volt, 3-phase open-delta transformer system, the line current holds significant importance in determining the operation and performance of the system. In this setup, the line current is equal to the coil or winding current because, in an open-delta configuration, the transformers are connected in such a way that the current flowing through the line is simply the current flowing through each transformer winding.

When examining the transformer connections, the open-delta configuration utilizes only two transformers instead of three. This results in a relationship where the line current experienced in each phase winding directly corresponds to the current produced in the system. Consequently, the current in the line can be expressed as the coil current, demonstrating a direct relationship between the two.

Understanding this relationship is essential for calculating load requirements, managing system efficiency, and ensuring that the transformers operate within their designated current ratings.