Check out this link. It explains neutral/ground bonding with small portable generators.
I don't know why the guy in that video calls 110vac outlets "Edison outlets". As I recall, the Edison electric grid was DC power, not AC. The Westinghouse grid was the AC grid & used the standard 110vac outlets. I would expect that the DC system used different outlets. If anyone knows different, please correct me.
That aside, I have a few points of general information to share -
Air conditioners draw a lot more current at start up than they do when they run. The text book calculation for sizing components for AC motor start up is 6 times running current. It is called locked rotor current. If a generator will start an air conditioner for even a few seconds, then it should be able to run it with no problems. The start up is the hard part. This is especially true on a hot start up, when the compressor has a load of head pressure on it.
Old fashioned brush generators have a pretty good tolerance for short duration heavy loading. The modern inverter generators generally lack this same level of start up current tolerance, even the good brand names. A friend of mine fried one of those Honda brief case generators trying to run a 8,000 BTU window shaker AC & a refrigerator during a hurricane power outage a couple of years ago. He then borrowed a spare generator from a neighbor. A 1500 watt brush generator was able to do the job that the 2000 watt inverter generator could not do.
When you put two AC generator outputss in parallel, you need to have them in phase sync, otherwise one will short circuit through the other. It's not as simple as just putting the output wires in parallel. There needs to be some kind of phase timing control system. In inverter generators, it may be possible to directly parallel the DC buss systems & feed a single inverter. It depends on the model you have.
Floating ground to neutral connections will often trip ground fault (GFCI) or residual current breakers. Connecting ground to neutral can often eliminate this problem. This is an oversimplified statement. There are a lot of details that really should be considered.
