Grounding the Onan

Got my reman Onan installed and all wired up except for one critical connection--where do I connect the ground wire on the Onan? The AC common ground. The rotary selector switch?
Many thanks. It's gettimng chilly here in NC and I would like some heat underway.

Oliver
Southern Lady GB 42 "Woodie"

Ground request

Doesn't anyone know the answer?
Oliver

Its hard to say without a wiring diagram of your boat, but I'd probably go to the AC common ground. The thing you need to watch with a gen is the AC neutral to ground bonding. When powering from the gen, the neutral and ground should be bonded. But when on shore power, that ground needs to be disconnected because the AC to neutral bond happens on shore and is carried to the boat via your power cord. I'm sure there are lots of ways to accomplish this, but I've typically seen it accomplished via the power selector switch.

Grounding

If I understand correctly the AC neutral should go to the boat's AC ground bus via the selector switch? That way when switched to shore power the connection is broken.
Oliver

That can work. The other way is to bond the neutral and ground at/inside the gen set, and disconnect/isolate the gen neutral when you deselect the gen at the selector switch.

I'll get out my Ohm meter and do some sleuthing. Meantime I have discovered something strange. The white neutral (not yet connected to the Onan) shows 30 volts on the Ohm meter when grounded to the Onan. The selector is on shore power.
Oliver

There should be a neutral White and ground green. Check the installation manual for exact instructions.


I'm not going to make suggestions on this very important issue because terminology already seems in question.They do go different places.

The generator gets grounded
The generator neutral gets bonded to ground as well

The selector switch should open both the neutral and the 120 volt lead.

Fix the reason you are seeing voltage on the neutral before proceeding

Will do. Thanks