Here's the stuff we found when you searched for "Okay here's the story, I'm an electrical engineer, and in US factories, most motors between 1 and 100 horsepower are typically run off of a three-phase 480 Volt AC feed. This is the line-to-line voltage, what you get if you measure the voltage across two of the phases. The line-to-neutral voltage is lower, 480V/sqrt(3), or 277 Volts AC, since you are only measuring one energized phase."

If you Log in you could create a "Okay here's the story, I'm an electrical engineer, and in US factories, most motors between 1 and 100 horsepower are typically run off of a three-phase 480 Volt AC feed. This is the line-to-line voltage, what you get if you measure the voltage across two of the phases. The line-to-neutral voltage is lower, 480V/sqrt(3), or 277 Volts AC, since you are only measuring one energized phase." node. If you don't already have an account, you can register here.