No Boom. well, i didn't have to turn output phase loss prevention off. I had it in constant torque w/ auto boost. changed it to constant torque and the problem went away. I think i know why, but not going to presume.
Assuming this is an Altivar ATV212 drive, the manual even warns you that the output phase loss can give you trouble with certain motors and may need to be disabled. Read the full instructions for F605.
That was probably exactly what I should have done. I was using constant torque w/ boost mode. Problem was probably that I was derating a drive, so the drive was using the torque boost based off of the default hp rating and would probably have been alright if i auto tuned.
I auto tuned, and then switched to constant torque and the problem went away. Customer wasn't in the correct mood to let me play.