If you look at the wiring diagram in the Owner's Manual you will see that there are two inverters (part of Control Unit) that are in fact connected in series or parallel via the Voltage Select Switch. In 120 volt mode you have double the current available than when in 240 volt mode. In 240 volt mode, you have the equivalent of two separate 3150 peak, 2750 running VA generators that happen to have a synchronized output. Only one of these two generators can be applied to an individual air conditioner. However, IMO, you should be able to run two of your air conditioners in 240 volt mode, but you have to do the same things that those of us with smaller generators have to do: Water heater on propane, fridge on propane, possibly switch power converter off, and possibly add start capacitor to the air conditioners. You're also susceptible to performance loss at higher elevations.
