Hi All,
I've read the many Giandel and Grounding threads on here for insight, but wanted to start a fresh thread for focus. I've also read the grounding download manual (which was very helpful), but I feel like I can't meet some of the specifications it mentions for 'Grounding Systems with Both AC & DC' for stationary systems (see attached image).
My System
See attached image for my off-grid, standalone system. This system will not be connected to GRID or any other type of existing electrical system.
This inverter has the usual terminals:
Giandel Manual
The Giandel manual says the ground screw is already connected to the ground wire of the AC output receptacle, which I confirmed via a multimeter continuity test between ground screw and AC ground receptacle. The manual says the ground screw should be used to ground the inverter to a ground wire, which will vary for vehicles (chassis), boats (ground system) and fixed locations (earth).
But here's my conundrum -------> I don't have a way to ground to earth, and I'm not in a vehicle or a boat. I'm off-grid in an isolated cabin/shed.
Grounding
So what I've done is ground the inverter to DC negative (using 4 AWG copper wire).
My thinking here is that this will act as a safety if something goes wrong (e.g. the inverter shorts to the frame of the unit)....the assumption being that ground current will flow directly to DC negative, which will eventually trip one of 2 x inline ANL fuses on the DC battery positive cables.
Other things to note:
- My DC system is not grounded - as in DC negative is not connected/bonded to earth.
- The Giandel manual says it has short circuit protection (see attached image).
- The inverter is not N-G bonded as far as I can tell (I could be wrong). The manual makes no mention of it (that I could see) and I don't get multimeter continuity between L-G and N-G. I also tested voltage between L-N, L-G and N-G and got ~240V, ~120V and ~120V, respectively.
Given all of the above, my questions are:
Thanks in advance guys.
Regards
George





I've read the many Giandel and Grounding threads on here for insight, but wanted to start a fresh thread for focus. I've also read the grounding download manual (which was very helpful), but I feel like I can't meet some of the specifications it mentions for 'Grounding Systems with Both AC & DC' for stationary systems (see attached image).
My System
See attached image for my off-grid, standalone system. This system will not be connected to GRID or any other type of existing electrical system.
This inverter has the usual terminals:
- DC positive terminal, DC negative terminal
- 2 x AC outputs
- A ground screw connection (see image)
Giandel Manual
The Giandel manual says the ground screw is already connected to the ground wire of the AC output receptacle, which I confirmed via a multimeter continuity test between ground screw and AC ground receptacle. The manual says the ground screw should be used to ground the inverter to a ground wire, which will vary for vehicles (chassis), boats (ground system) and fixed locations (earth).
But here's my conundrum -------> I don't have a way to ground to earth, and I'm not in a vehicle or a boat. I'm off-grid in an isolated cabin/shed.
Grounding
So what I've done is ground the inverter to DC negative (using 4 AWG copper wire).
My thinking here is that this will act as a safety if something goes wrong (e.g. the inverter shorts to the frame of the unit)....the assumption being that ground current will flow directly to DC negative, which will eventually trip one of 2 x inline ANL fuses on the DC battery positive cables.
Other things to note:
- My DC system is not grounded - as in DC negative is not connected/bonded to earth.
- The Giandel manual says it has short circuit protection (see attached image).
- The inverter is not N-G bonded as far as I can tell (I could be wrong). The manual makes no mention of it (that I could see) and I don't get multimeter continuity between L-G and N-G. I also tested voltage between L-N, L-G and N-G and got ~240V, ~120V and ~120V, respectively.
Given all of the above, my questions are:
- Does grounding the inverter to DC negative offer the safety protection that I've assumed it does? If not, why not?
- Will sending AC ground current to DC negative be an issue? If so, why?
- Does it matter if my DC system is not grounded itself? PS, I've read many PROS and CONS around this and there seems to be a slight general consensus that DC grounding is not an ultimate show-stopper.
- What are the downsides of not being able to directly ground the inverter on the AC side to earth?
- Is there anything else I should do to improve my grounding safety?
Thanks in advance guys.
Regards
George




