Here is a little test to see if there is sufficient power.
1. check for proper wiring with a three light plug in
2. check voltage inside RV with a kill-o-watt unit
3. place a cup of water in the microwave and turn it on for one minute
4. observe how much voltage drop there is. (the kill-o-watt must be on the same circuit) If voltage drops below 109 then there is not sufficient power to operate the microwave.
I have an adapter for my kill-o-watt that goes from thirty amp to 15 amp--and I plug the 3 light tester into the kill-o-watt. This gives me voltage and the other information I need to know if it is safe to plug in.
Why did I choose the microwave? Because in my RV it draws the greatest number of watts (1531) of any electrical device in my motor home. If I can run it, then there is no problem with running the air conditioner.