Would the following set-up work: 30AMP double-pole breaker in panel, 12-2 NM to single 30AMP 220V receptacle, black and white hot ,with white wire marked with black tape? Ran wire anticipating 110v a/c, lady with the checkbook( my wife) thinks that we will end up with 220V unit. I f that's the case will above set-up work? Or do I need to pull 10-2 to outlet?