Absent green AC grounding wire, sort of

[US1Fountain]

Not going into the green grounding wire debate here



Doing some work on my cruiser and I noticed there is no green grounding wire going to the engine ground stud. My previous boat, same brand and model but 2 yrs newer ('95) had this wire going to the motors. That boat did not have a gen. Current boat has a gen. Neither boat has an inverter.
With the shorepower unplugged, today using my DVM at my shore panel, I checked for continuity across the AC ground buss and DC neg buss at the shore panel and I have continuity. So today I searched for the point of connection between the 2. I pulled the electrical panel cover off my generator and inside the box, the green is connected to the ground lug inside the box, via a jumper wire. There is a battery ground cable that connects the generators engine block to the ground stud on the main engine. (No actual wire from the electrical boxes ground stud to the engine block, just the metal electrical box itself bolted to the motor) So in actuality, there is a green grounding wire path connection between the AC grounding buss of the shore panel, to the main motor stud. Its just not a direct path single wire as I would think best.

Is this the normal US method of boats with generators? I'm inclined to run a single wire from the shore panel AC grounding buss to the motor ground stud.

[smac999]

the engine blocks should not be be used as a ground bus. ideally you'd have one neg wire from the engine to a DC neg bus on the boat. the batteries also having a single neg wire to that block. and gen neg. the AC panel ground bus to that bus. and bonding system wire to that bus, if you have one. chargers / inverters ect. neg feed to DC panel.

you'll probablay find AC to DC continulity in a few different places. most battery chargers and inverters do it too internally. so you may end up with that bond in multi places.

if the AC and DC panel are side by Side. often this wire just goes from the AC panel bus to the DC panel bus. side by side. so you can follow it and see it. no need to run a 10awg cable all the way back to the large neg bus. when the DC panel neg bus will handle 30a no problem

[US1Fountain]

Great, Thanks