Some smaller units you can, but I know that on my coach I can only run one with a thirty amp shore power. I have to have 50 amp in order to run everything on the coach.
Just went out and checked to see exactly what my coach has and they are both Coleman HP2 air conditioner and heat pumps. The air conditioners are 15,000 BTU and the Heat pumps are 12,700 BTU. The air conditioners draw 16 amps each and that is why on 30 amp service if I turn both on, it will trip the shore power circuit breaker.
But I have seen the smaller 13,500 btu air conditioners both working on thirty amps. But you are pushing it and can not activate a microwave or anything else.