MY A/Cs are original 21yrs old
my Onan was run all day yesterday 116 degrees and all night
it has been running since 7am Friday morning, i expect to run it until sometime sunday night maybe longer
my kill-a-watt plugged into the kitchen outlet reads 118.2v
my digital handheld multi-meter reads from 118.3-119.x
my clamp on ampmeter reads 14.97amps load for the (1) A/C unit i could get the meter on in the breaker panel (rear a/c)
with both a/c units (2) portable fans 12" & 6", and laptop
i'm most likely over 30amps, total !
i can't get the ampmeter clamp around every wire i would like too test, in order to get total amount readings
the problem for you is switching over
you should turn off both A/C
unplug shore power
then start generator, let it warm for 2 minutes
then restart the A/C units one at a time
give each A/C 5 minutes or more of fan to help relieve compressor head pressure before switching to a cool mode
and give the first A/C on cool a few minutes to reduce compressor load before starting second A/C
same process when going back to shore power
even more important when going back to shore power or you can damage the generator DOING a 'POWER HOT' switch OVER