My 'guess' is that you may have a problem trying to run both a/c's on 30 amps, especially if both are 15K Btu. They can draw between 12 and 15 amps each or about 1500 watts each while running. A 30 amp RV system is 3600 watts while a 50 amp system is 12,000 watts. These RV a/c's have a peak of about 3500 during the startup phase. Now with these simple numbers - maybe, but then, maybe not. I don't try to run both of ours since replacing an a/c with a failed motor/compressor or even a failed pigtail is not in my dollar or time budget. My recommendation - run the main area during the day, starting the BR a/c a half hour before bedtime and after shutting down the main area unit. I'm not even going to get into a CGs power delivery system as there are way too many variables with surges and over/undervoltage spikes