In a 3Ø, 4-W supply system delivering 120/208 volts, what is the line-to-line voltage?

In a three-phase, four-wire supply system such as the one described, the line-to-line voltage can be determined from the line-to-neutral voltage provided. In this case, the system delivers 120/208 volts. The 120 volts is the line-to-neutral voltage, which is the voltage measured from any one of the phase conductors to the neutral wire.

The line-to-line voltage in a three-phase system can be calculated using the formula:

[

V_{LL} = V_{LN} \times \sqrt{3}

]

Where ( V_{LL} ) is the line-to-line voltage, and ( V_{LN} ) is the line-to-neutral voltage. Therefore, when you take the line-to-neutral voltage of 120 volts and multiply it by the square root of 3 (approximately 1.732), it results in:

[

V_{LL} = 120 , V \times 1.732 \approx 208 , V

]

Thus, the line-to-line voltage in this 120/208 volt system is accurately identified as 208 volts.