Well, I have separated all the 220AC ground wires at the 220 box in the galley and at the 220 boxes in the engine room. I found that the output cable from the generator is grounded to the generator case, and thus, to the bonding system. The other end of that cable goes to the automatic switch that chooses generator over shore power, where it is connected to all other 220 grounds via the output from the switch.
This violates my understanding that the 220AC ground should NOT be connected to the bonding system. Now what????