Yesterday I noticed my pump wasn't running during the scheduled times so I went to see if my wife had shut it off for some reason (trying to save power). The display on the pump shows "Drive Error! AC voltage too low". What does this actually mean, and what can I do about it? Based on my limited electrical understanding, it should be getting voltage, or not, the amount of power going to the pump can't change. And if it did it should just be off if it's not getting enough power.