On a 277/480 3-phase 4-wire system, what is the voltage to ground?

In a 277/480 volt three-phase four-wire system, the voltage to ground is derived from the phase-to-neutral voltage. In this configuration, the phase-to-phase voltage is 480 volts. Each phase has a corresponding voltage to ground that can be calculated as follows:

For a three-phase system, the relationship between phase-to-phase voltage (line voltage) and phase-to-ground voltage (line-to-neutral voltage) is established based on the square root of 3 (approximately 1.732). In a wye (Y) configuration, where this system is commonly found, the line-to-neutral voltage can be found with the formula:

[

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

]

For the given system, the voltage to ground (which is the phase-to-neutral voltage) is calculated as:

[

V_{LN} = \frac{480V}{\sqrt{3}} \approx 277V

]

Thus, in this system, the voltage to ground is 277 volts for each of the three phases. This is the correct answer. Recognizing that the system operates with a neutral point allows us to identify that each phase maintains this same 277 volts to ground