What is the BØ-to-neutral voltage when a 3Ø, 4-W supply system delivers 120/240 volts?

In a three-phase, four-wire (3Ø, 4-W) supply system, the voltage configuration typically involves phase conductors and a neutral conductor. When the system delivers 120/240 volts, it means that the system is designed to provide both 120 volts across a single phase wire to neutral and 240 volts across two phase wires.

In most configurations of a 3Ø system, particularly one that serves both 120-volt and 240-volt applications, the phase-to-neutral voltage is indeed 120 volts. However, for a three-phase system, the line-to-line (or phase-to-phase) voltage is different. The line-to-line voltage is calculated based on the formula:

[

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

]

If you take the 120 volts as the phase-to-neutral voltage, when applying this formula, the line-to-neutral voltage for a balanced system helps derive that, under certain square-root factors, line-to-line voltage can indeed reflect 208 volts when considering the three-phase configuration. This 208 volts represents the voltage between the phases themselves, typically encountered in a 120/208 volt service, differentiating from the straightforward 240 volts in a split