Generators, air c., capacitor

[geezerbob]

This summer a new Champion 3100/2800 ran the 13.5 ac (brand?) on our 2011 x23b no problem. Now on our 2016 23rlsw Dometic 13.5 ac the Champion would kick out on ac start up. Ran fan first still kicked out. All filters etc clean.
Ran the ac on shore power, ac started and ran good no problem.
Ran on shore power for 30 minutes. Hooked Champion back up then it would run ac with the overload light flashing just once on start up. Leave the ac until next day and the same scenario would occur.
I installed a hard start capacitor recommended by Dometic.
Now the Champion starts the Dometic ac first time every time.
Learning for me: Even though the 3100/2800 should start the ac no problem a hard start capacitor may need to be added. Don't assume anything.
My Dometic ac 54921844 13.5 mfg B9175-711C0
Dometic hard start capacitor kit part # 3310727.015
Easy to install.
Bob