I just witnessed my compressor reversing. We had a pretty good power dip to about 50V and was only momentary. I thought to go check the AC immediately and it was very loud. I figured it reversed and shut down immediately. Probably ran for 20sec that way. Afterwards, I went to look at the condensor and both the suction and liquid lines were cool. I waited a few minutes and restarted the system and it runs fine.
Had I not been around, I am sure it either would have blown the fuses, tripped something else out, or blown up. I would like to protect the system from future occurances. No one else in the house would know to shut it down.