[QUOTE=Rich B;348368 Change the breaker to a 20 or a 15 if you like and install a good quality recepticle that will fit the AC unit. A single is a good way to limit the circuit to just that AC unit.
I will probably get bashed for something being wrong or not to code but I expect it here.....[/QUOTE]
Oh, and changing the breaker is just NOT optional, it is essential. It is just flat wrong to use a 30 amp breaker in this circumstance. The single receptacle is required by code, but so what? The AC is running and someone comes along and plugs in a vacuum, it is all protected at 30 amp, and the OP has installed a 15 amp receptacle, what happens next?
The OP is well advised to study up and do it right, or if he does not want to take any chances, call an electrician in.