Refer to a transformer that supplies 120/208 volts on its secondary windings. This means that each winding (X1 to X2 or X3 to X4) is supplying ___ volts.

Refer to a transformer that supplies 120/208 volts on its secondary windings. This means that each winding (X1 to X2 or X3 to X4) is supplying ___ volts.

• A. 120
• B. 208
• C. 240
• D. 277

Answer: (A)

Each winding supplies 120 volts. In a 120/208 V secondary, the 120 V is the voltage across an individual coil (phase-to-neutral in a typical 3-phase wye connection), while the 208 V refers to the line-to-line voltage between two phases, which is √3 times 120 V. So measuring across a single winding like X1–X2 or X3–X4 gives 120 V.

Each winding supplies 120 volts. In a 120/208 V secondary, the 120 V is the voltage across an individual coil (phase-to-neutral in a typical 3-phase wye connection), while the 208 V refers to the line-to-line voltage between two phases, which is √3 times 120 V. So measuring across a single winding like X1–X2 or X3–X4 gives 120 V.