Our air conditioner occasionally blows a fuse. Any idea what needs to be done and how much money to fix?

It doesn't happen often, but every now and then, right as the air conditioner tries to kick on, it will blow a fuse, and I'll need to go to the fusebox to reset that particular fuse. Then it's fine, and the air conditioner works no problem. This doesn't happen very often, but it is annoying. Anyone experience a problem like this before, and any idea what needs to be done and what cost something like this should be for an electrician? Thanks.