When you have 30 amp service, you can only run 1 Roof AC. You do not state year model of RV
Roof AC---- pulls about 14 amps on HI FAN COOL. So 28 amps, leaving you 2 amps to run everything else.
Power Converter ----pulls about 1 to 3 amps depending on DC load
Refer pulls 2.5 to 3.0 amps
Water Heater IF equipped with 120 element----11 amps. Not usually on a 30 amp RV
Microwave depends on Wattage but 7 to 10 amps.
So, you install that 2nd AC. Well, you will not have room for the extra required 20 amp breaker for it in the 120 breaker panel. RV AC units require a dedicated 20 amp breaker. USUALLY, the Rear Bedroom prewired roof vent that wire goes to the GENSET. That requires at least a 5000 to 5500 watt Genset which probably was not optioned on your RV. You probably have a 4.0kw Genset.
