Another possible issue: IN days of old there was a company who's web page was, as I recall PSRV dot NET, Now gone.. but they made an adapter that let you use both A/C's on a 30 amp site.... By doing a "Break out" on one of them..
The adapter consisted of a box with an inlet (Mounted Plug) an outlet on a pigtail (Like the outlet end of a 12ga extension cord) and a circuit breaker.
If you have one of those the outlet may have been pulled off (handy for say running an air compressor for winterizing, DOne that in fact) or the breaker tripped.