Goodwe ES back up (UPS) neutral connection

[Fuenkli]

Is it ok/safe/legal to connect the inverter back up (UPS) neutral on a Goodwe ES inverter to the grid neutral? Basically in line with the Aussie (MEN) requirement (see attachment). The advantage of this is that only one neutral wire between inverter and DB board is required.

[DunnPenny]

I have a set of drawings showing the neutral wire coming from a UPS being connected to the Neutral wire of the source for a common neutral. To me this seems like a code violation, but I am unable to confirm this in the NEC. Could this possibly burn up the UPS as well?

[Fuenkli]

Hi DunnPenny,

I am not sure exactly what your set up is. My issue is very specific to the Goodwe ES inverter (or I guess any other GT hybrid inverter with a back up UPS functionality). I decided not to bridge the back up (UPS) and grid neutrals because this would (if the inverter goes into back up mode) create an earth neutral bond on my property which is illegal in South Africa. I do however think that it would cause no harm to the Inverter.