I have a EG4 3kw inverter/charge controller. From my reading, it dynamically creates a ground-neutral bond when not receiving power on its AC input (i.e. the grid / generator input). EG4's assumption seems to be that with grid supplied power, the grid supplies the ground-neutral bond, and for all other circumstances, the inverter should supply it. This seems to work well for everything except when a generator is supplying power to the AC input on the inverter...
In my use case, there is no grid power. Never has been, never will be. 99.9% of the time it will be running off solar & batteries, so the dynamic ground-neutral bond will be activated by the inverter. My breaker box will have ground and neutral separated, so while running of solar & batteries the only point of ground-neutral bond will be the one in the inverter, which is ideal. (I say "ideal" because there is exactly 1 bond, as there should be)
The complication is if ever need to connect a generator. As I understand it, then the ground-neutral bond in the inverter will be deactivated.
So, my plan is: on the AC input to the inverter (the grid/generator input, which in my case would only ever be connected to a generator), I intend connect the ground and neutral at the AC input to the inverter. Clearly this would create a loop if connected to grid power. Seems like the simple solution for generator use. That means if I plug in a generator, when the inverter kicks over to use it, the internal ground-neutral bond is deactivated and the bond I created on the AC input cable is the only point of ground-neutral bond. So we maintain exactly 1 bond.
Alternatively, I could easily create a ground-neutral bond within my breaker box, then there would always be at least 1 bond. But that would create a ground loop most of the time. As I understand it, that would be mostly safe, except under some odd maintenance circumstances I don't recall, and the loop would be prone to creating interference.
This is in the US, so its 120v power, but its a rural area with no inspections. (I'd happily let them inspect it, but the governing authority doesn't inspect off-grid electrical) So there are no code compliance concerns for the sake compliance, but I am very interested in having it be safe.
I've done a lot of reading on this forum. I think some would suggest creating the ground loop and say I shouldn't worry about it. Others (the pickier ones) I think would approve of my plan, with a big caveat that it shouldn't be connected to grid power with my bonding of the ground-neutral at the inverter's AC input.
So... did I get that right?
In my use case, there is no grid power. Never has been, never will be. 99.9% of the time it will be running off solar & batteries, so the dynamic ground-neutral bond will be activated by the inverter. My breaker box will have ground and neutral separated, so while running of solar & batteries the only point of ground-neutral bond will be the one in the inverter, which is ideal. (I say "ideal" because there is exactly 1 bond, as there should be)
The complication is if ever need to connect a generator. As I understand it, then the ground-neutral bond in the inverter will be deactivated.
So, my plan is: on the AC input to the inverter (the grid/generator input, which in my case would only ever be connected to a generator), I intend connect the ground and neutral at the AC input to the inverter. Clearly this would create a loop if connected to grid power. Seems like the simple solution for generator use. That means if I plug in a generator, when the inverter kicks over to use it, the internal ground-neutral bond is deactivated and the bond I created on the AC input cable is the only point of ground-neutral bond. So we maintain exactly 1 bond.
Alternatively, I could easily create a ground-neutral bond within my breaker box, then there would always be at least 1 bond. But that would create a ground loop most of the time. As I understand it, that would be mostly safe, except under some odd maintenance circumstances I don't recall, and the loop would be prone to creating interference.
This is in the US, so its 120v power, but its a rural area with no inspections. (I'd happily let them inspect it, but the governing authority doesn't inspect off-grid electrical) So there are no code compliance concerns for the sake compliance, but I am very interested in having it be safe.
I've done a lot of reading on this forum. I think some would suggest creating the ground loop and say I shouldn't worry about it. Others (the pickier ones) I think would approve of my plan, with a big caveat that it shouldn't be connected to grid power with my bonding of the ground-neutral at the inverter's AC input.
So... did I get that right?
