Check out your A/Cs. YOu see you have not given enough information.
Background: I have two A/Cs as well both draw the SAME AMOUNT OF POWER when running, only one is 13,500 BTU and the other 15,000.. The bigger one is newer and they are doing a more efficient job.
So look at the labels on your A/C. find out the power draw.
Second: On both of my A/Cs if I do not get up ther and clean them from time to time the condenser (hot) coils clog up with dirt and debris and **** that's in the air.. When this happens they can not cool the refrigerant enough and system pressure increases.. The compressor works harder and draws more current, Up to 10 amps more.. Then the breaker trips and I get the message. I saw one of mine go from 21 amps (more than the 20 amp breaker could take) to 13.5 by actual measurement when I cleaned it.
And finally.. Generator may need a tune up.