When the output voltage is 120/208, how are the secondaries connected?

The correct answer is based on understanding how the voltage levels are achieved in a three-phase system. In a 120/208 volt system, the voltages represent the line-to-neutral voltage (120 volts) and the line-to-line voltage (208 volts). This specific voltage configuration typically signifies the use of a wye (or star) connection for the secondaries.

In a wye connection, each of the three phases is connected to a common neutral point. This configuration produces the line-to-neutral voltage of 120 volts. The line-to-line voltage is then calculated by multiplying the line-to-neutral voltage by the square root of three (approximately 1.732), resulting in a line-to-line voltage of about 208 volts.

The other options do not appropriately describe the configuration needed for a 120/208 system. A series connection does not apply in this context, as that would involve combining voltages rather than establishing them in a phased manner for alternating current systems. Paralleled windings usually refer to connections that aim to increase current capacity rather than setting specific voltage levels. Direct connection is too vague as it does not pertain to any standard phase connection type.

Thus, the correct interpretation of a 120/208 output voltage necessitates