Basically, running one a/c is never a problem with 30 amp service. I have occasionally run both of my a/c on 30 amp service, but you have to insure every other appliance that draws more amps than your lights remains off. This would include microwave, electric water heater, fireplace, furnace fan, electric fridge, furnace fans, hair dryer, etc. You get the gist.
I have always been able to run the majority of my fifth wheel on 30 amp service as long as I only run one a/c. That includes my water heater and fridge both set on electric.
The big advantage to being on a true 50 anp rv service (which is really a total of 100 amps) is that you can almost always run everything at the same time. All a/c, microwave, coffee pot, etc.
2016 F350 CC Dually Powerstroke 4x4
2014 Cedar Creek 34RLSA w/Level Up
2007 HD Ultra Classic 103
USS Pyro AE-24 WestPac MM2 '71-'75