In a 3Ø, 4-W supply system delivering 277/480 volts, what are the line-to-neutral voltages?

In a three-phase, four-wire (3Ø, 4-W) supply system that provides 277/480 volts, the line-to-neutral voltages can be determined by understanding how the voltage is configured in a three-phase system.

In this setup, 480 volts is the line-to-line voltage, which is the voltage measured between any two of the three phases. The line-to-neutral voltage is derived from the line-to-line voltage using the square root of 3, since it corresponds to the relationship in a balanced three-phase system.

To calculate the line-to-neutral voltage from the line-to-line voltage, you can use the following formula:

Line-to-neutral voltage = Line-to-line voltage / √3.

For this system, when you take the line-to-line voltage of 480 volts and apply this conversion:

Line-to-neutral voltage = 480 volts / √3 ≈ 277 volts.

This calculation shows that the line-to-neutral voltage in a 3Ø, 4-W system delivering 277/480 volts is indeed 277 volts. Therefore, the correct answer reflects the line-to-neutral voltage, which is important for determining the voltage available for single-phase loads connected to the neutral. This distinction highlights why the chosen answer is