I installed new 11.0k Dometic Penguin roof AC's on my camper to replace 13.5k Brisk II's because of a constant overload condition. The new AC's only draw 10.5 amps versus 12.0 amps. I even set the thermostat knob to 50% and never move it past 75% and still get an overload condition. If the 3000iSEB can't run an 11.0k AC, then what are they good for? Running a 60 watt light bulb? Any troubleshooting tips, because the manual is useless and the Yamaha technical people obviously don't read this forum.
Quick google search reveals old posts making reference to a dealer fixing a hard start by adding a switch and making it "generator ready" without providing specifics. Someone else said "running amps vs. LRA" at startup are two different things. If it was me, I'd find a way to see what the AC was drawing during startup when on street power, and comparing that to Yamaha specs.