Gene Good point and understood. Your note about anywhere else behind the isolator will not matter, needs discussed. The neutral and ground are connected at the inverter. If that neutral and ground connection is not disconnected when not in use, you have a Dc ground path around the isolator via the neutral wire off the boat. If this inverter is connected where he ran ground to the main ground and main neutral buses at the AC panel. Dc current will run by the isolator via neutral to source off the boat where the neutral nc ground is connected again and back to DC Source. Just because you have a isolator does not stop DC current from using other conductors, if the conductor is somehow connected to the ground. Examples: household appliances where the neutral is connected to the case where the case ground is connected. Household appliances installed on vessels should always case the case neutral removed. It allows a ground to neutral connection and causes issues with current flow. Examples: tv cables. These cables alway cause a DC path off the vessel around the isolator. The TV cable ground can be connected to the vessel ground and allow a path. We never want the neutral connected anywhere to a ground on the vessel. We see this a lot with inverters when they install them with the neutral directly connected to the main Ac panel and the ground without a drop out or double pole breaker. If this install went directly to the old generator breaker, make before break, the generator double pole breaker would break the connection on the neutral and that would work. The only other issue would he would be powering the whole panel and the inverter would be overloaded. That is why I originally asked some of the questions to determine how the install was done at the panel. He may have separated his neutrals at the panel and when the inverter is in use, it only powers the small loads. We have tested and corrected a many inverter installs with the neutral path around the isolator with a neutral ground connection on the vessel. Hope this helps all. Stay Well Brig > On Jan 4, 2022, at 3:30 AM, sentoa-request@lists.sentoa.org wrote: > > net)

That is more or less correct, but it is a different topic. Old inverters defaulted to connecting the neutral and ground when not powered by incoming AC, whether or the inverter was in use or not. Newer inverters default to connecting the neutral and ground only when no AC is present and the inverter is active. I would guess that the inverter in this topic is new. (It is hard to understand why anyone would have a TV cable connected but no shore power.) Gene Fuller *Yorkshire Rose* NT 37-136 Punta Gorda, FL

To All Little info that may help all. It is a simple test to determine if you have a neutral ground connection onboard. Make sure all your AC power services are not supplying power. Make sure all your double pole breakers onboard are closed. Disconnect your shore power cord and test continuity between the neutral and ground. Also if you have two 30 amp services, the neutrals for each service should not be connected and run separately to the loads. You can test continuity between the two neutrals on the shore power cords. Hope that helps. Brig Sent from my iPhone > On Jan 4, 2022, at 8:00 AM, Captain Brig <captainbrig@gmail.com> wrote: > > Gene > > Good point and understood. Your note about anywhere else behind the isolator will not matter, needs discussed. The neutral and ground are connected at the inverter. If that neutral and ground connection is not disconnected when not in use, you have a Dc ground path around the isolator via the neutral wire off the boat. If this inverter is connected where he ran ground to the main ground and main neutral buses at the AC panel. Dc current will run by the isolator via neutral to source off the boat where the neutral nc ground is connected again and back to DC Source. Just because you have a isolator does not stop DC current from using other conductors, if the conductor is somehow connected to the ground. Examples: household appliances where the neutral is connected to the case where the case ground is connected. Household appliances installed on vessels should always case the case neutral removed. It allows a ground to neutral connection and causes issues with current flow. Examples: tv cables. These cables alway cause a DC path off the vessel around the isolator. The TV cable ground can be connected to the vessel ground and allow a path. We never want the neutral connected anywhere to a ground on the vessel. We see this a lot with inverters when they install them with the neutral directly connected to the main Ac panel and the ground without a drop out or double pole breaker. > > If this install went directly to the old generator breaker, make before break, the generator double pole breaker would break the connection on the neutral and that would work. The only other issue would he would be powering the whole panel and the inverter would be overloaded. That is why I originally asked some of the questions to determine how the install was done at the panel. He may have separated his neutrals at the panel and when the inverter is in use, it only powers the small loads. > > We have tested and corrected a many inverter installs with the neutral path around the isolator with a neutral ground connection on the vessel. > > Hope this helps all. > > Stay Well Brig > >> On Jan 4, 2022, at 3:30 AM, sentoa-request@lists.sentoa.org wrote: >> >> net)