2800 watts will run the usual RV AC, but if that generator puts out 240 volts, it means that it is rated to produce 2800 watts on both halves of the windings, or 1400 watts on each 120 volt side. Some such generators can sometimes put out the full 2800 watts on one side only, but sometimes that comes at the price of low voltage or other weird behavior. For what it is worth, it is not worth the trouble of attempting to use a generator that small that way. You need a step-down transformer to convert 240 volt power to 120 volt power, thus using both sides of the windings as the generator mfg intended, or you might cause damage to either the generator or the AC, or perhaps both. Better yet, get a proper 120 volt, 2800 watt generator.
