Friedrich 220v TwinTemp Air Conditioner installed in my garage keeps tripping fuse why?

It would usually work for days then occasionally trip and i would unplug it for a few hours plug it back in and it would work again. It has one of those built on fuse/tester/reset things on the actual plug. Eventually I would find it (fuse/tester/reset thing) tripped again and the garage warm usually a few days to week later. I had begun leaving it off because of this unless I had planned to spend alot of time in there. Recently during a surge from a storm it did this again and won't come back on now every time I plug it in the (fuse/tester/reset thing) keeps tripping instantly once its plugged into outlet even after two days of not having it plugged in or used. Any advise?