In a 3-phase wye system with a neutral, which line-to-neutral voltage is commonly seen in a 120/208 V distribution?

In a 3-phase wye system with a neutral, which line-to-neutral voltage is commonly seen in a 120/208 V distribution?

• A. 277 V
• B. 120 V
• C. 480 V
• D. 208 V

Answer: (B)

In a 3-phase wye system with a neutral, each line-to-neutral voltage equals the phase voltage, and the line-to-line voltage is √3 times that phase voltage. For a 120/208 V distribution, the phase voltage is 120 V, so the line-to-neutral voltage is 120 V. The line-to-line voltage between two phases becomes 120 × √3 ≈ 208 V, which is why 208 V is seen as the between-lines voltage. The other values correspond to different systems: 277 V would be the line-to-neutral in a 480Y/277 V system, and 480 V is the line-to-line voltage in a 480 V system.

In a 3-phase wye system with a neutral, each line-to-neutral voltage equals the phase voltage, and the line-to-line voltage is √3 times that phase voltage. For a 120/208 V distribution, the phase voltage is 120 V, so the line-to-neutral voltage is 120 V. The line-to-line voltage between two phases becomes 120 × √3 ≈ 208 V, which is why 208 V is seen as the between-lines voltage. The other values correspond to different systems: 277 V would be the line-to-neutral in a 480Y/277 V system, and 480 V is the line-to-line voltage in a 480 V system.