Manholt,
It is the Cummins/Onan QD8000.
Kaypsmith,
As soon as I get back to the coach I will follow up on the generator ground connection with Fleetwood electrical schematics in hand.
The Magnum remotes plug into the inverter/charger with a communication/data cable and if it is sensing "High ACV" when shutting down the generator, then it has to be originated from my (generator) AC lines coming the Transfer Switch.
I have checked all my connections inside the Transfer Switch and they are tight and unremarkable. My next step will be to check my AC connections in each unit.