In a 480V three-phase system, what are the typical line-to-line and line-to-neutral voltages for a wye configuration?

• A. Line-to-line ≈ 480 V; Line-to-neutral ≈ 277 V.
• B. Line-to-line ≈ 277 V; Line-to-neutral ≈ 480 V.
• C. Line-to-line ≈ 600 V; Line-to-neutral ≈ 346 V.
• D. Line-to-line ≈ 240 V; Line-to-neutral ≈ 120 V.

Answer: (A)

In a three-phase wye system, the line-to-line voltage is √3 times the line-to-neutral voltage. So if the system is 480 V line-to-line, the line-to-neutral voltage is 480 ÷ √3, which is about 277 V. This pairing—480 V line-to-line with roughly 277 V line-to-neutral—is the common 480Y/277 V configuration used in industry. The other options correspond to different system voltages (for example, a 600 V LL system with about 346 V LN, or a 240 V LL system with 120 V LN) and don’t apply to a 480 V wye system.