I changed out a motor yesterday. Hooked it up and it was running backwards. Nothing changed on the power side, just the motor. Am I correct in my thinking that different motors have different phase rotation? Meaning two different motors hooked up the same way, may not always have the same rotation. Is this a difference in the windings of the motor? I swapped the leads in the disconnect wich were already swapped from the last motor. They were YOB, and I put them back to BOY. Someone here said that if a motor is hooked up properly phase rotation should always be the same. I was always under the assumption that whenever you install a new motor you have a 50/50 chance of the rotation being correct. I guess I do not have a very good understanding of the theory of phase rotation. The motor was a 15hp at 480v. Not sure of the type. It was a 9 wire motor?