If the phase voltage in a wye-connected load is 277 V, what is the line-to-line voltage?

If the phase voltage in a wye-connected load is 277 V, what is the line-to-line voltage?

• A. 240 V
• B. 480 V
• C. 600 V
• D. 380 V

Answer: (B)

In a wye-connected (or star-connected) system, the relationship between phase voltage and line-to-line voltage is defined by the equation: \[ V_{LL} = V_{PH} \times \sqrt{3} \] where \( V_{LL} \) is the line-to-line voltage and \( V_{PH} \) is the phase voltage. Given that the phase voltage is 277 V, we can calculate the line-to-line voltage as follows: 1. Multiply the phase voltage by the square root of 3: \[ V_{LL} = 277 \times \sqrt{3} \] 2. The square root of 3 is approximately 1.732: \[ V_{LL} \approx 277 \times 1.732 \approx 480.18 V \] This rounds to approximately 480 V. Thus, the correct line-to-line voltage corresponding to a phase voltage of 277 V in a wye-connected system is indeed 480 V.

In a wye-connected (or star-connected) system, the relationship between phase voltage and line-to-line voltage is defined by the equation:

[ V_{LL} = V_{PH} \times \sqrt{3} ]

where ( V_{LL} ) is the line-to-line voltage and ( V_{PH} ) is the phase voltage.

Given that the phase voltage is 277 V, we can calculate the line-to-line voltage as follows:

1. Multiply the phase voltage by the square root of 3:

[ V_{LL} = 277 \times \sqrt{3} ]

2. The square root of 3 is approximately 1.732:

[ V_{LL} \approx 277 \times 1.732 \approx 480.18 V ]

This rounds to approximately 480 V. Thus, the correct line-to-line voltage corresponding to a phase voltage of 277 V in a wye-connected system is indeed 480 V.