I am using my motorhome as an office. I am using a portable AC unit because the main AC in the RV does not work. I have the portable AC unit plugged into a surge protector along with a printer. On really hot days, the surge protector will shut off by itself. If I reset the surge protector it works for 5 minutes or so before shutting off again. I'm not sure if something is wrong with my portable AC, or the power strip, or the outlet in the RV. Professional advice would be GREATLY appreciated.

You are overloading the surge protector/power strip.