I am not sure of your application, but most houshold fans will not run in reverse, and if you mess with it, it will probably short your breaker or fan. If you reverse the wires on a single phase AC it will probably run normally but in the same direction. There are fans that are split-phase and can be wired for either rotation, but are mostly industrial. Not to say you cant take the blades off, and turn them over, depending on the type of fan !:thumbsup: