Are you sure you have a 50 amp generator. I have 50 amp power box for shore power but my generator is only 30 amps. What is the rating on the breaker for the refer and the A/C's. Each one of my A/C's have their own 15 amp breakers and the refer also has a 15 amp breaker.
I do not have any problems running all three on my generator. However, I do start them one at a time.
When you said you are reading 121 to 122 are you talking volts or amps?
1997 Triple E Empress, Freightliner Chassis, CAT 3126 w/ 275 horse's.
MD 3600 Tranny, 2011 Ford Escape Hybrid w/Blue Ox tow bar and Roadmaster Base Plate.
Amsoil Synthetic Oil only for my baby.