What voltage is delivered by each transformer in a bank when rated primary voltage is applied?

In a transformer bank, particularly in a three-phase system, transformers are commonly configured to provide a specific output voltage based on their design and the primary voltage applied. When a primary voltage is applied, the output voltage is determined by the turns ratio of the transformers in the bank.

A 120/240 volt transformer bank means that each transformer can deliver either 120 volts or 240 volts depending on how the secondary windings are used. When connected in a typical residential and light commercial configuration, transformers can be arranged to provide both voltages simultaneously—120 volts for standard circuits and 240 volts for heavier loads. Thus, applying the rated primary voltage results in an output that is either 120 volts or 240 volts, depending on the load and connection method.

This versatility makes 120/240 volts the correct answer, as it accurately describes the capability of each transformer in the bank to deliver both voltages when the rated primary voltage is applied.