Wiring Review - (Common Neutral) - Dual inverter with Grid (Split-Phase 120V/240V)

[sv308]

Hello
I currently have this sysem in operation and am not having any issues at all - I had a hard time finding the exact same setup but i wanted to get some opinions on it to see if using a Common Neutral between input and output is really frowned upon.

This was based on information found in this very helpful guide - https://diysolarforum.com/resources/grounding-and-bonding-the-mpp-lv6548-inverter.323/

The main difference in my diagram below compared to the original #9 from the guide is that i show a direct connection from the grid to the critical load box.
I choose between the grid or inverters using a interlock kit installed on that panel.


Any input would be great - thanks!




Here is the Appendix A referenced from the diagram above

 

[Adam De Lay]

@FilterGuy

 

[Adam De Lay]

What inverters are you talking about?

 

[sv308]

2x SP6548 specifically - which to my understanding are almost identical to the LV6548

 

[Adam De Lay]

2x SP6548 specifically - which to my understanding are almost identical to the LV6548

I had a pair of the EG4 6500s. The last firmware update that was released modified the inverters to create a common neutral setup (if configured properly).

To my knowledge the MPP and SP haven't modified their firmware the same way as EG4 to actually create a common neutral (which seems to a common way a lot of other inverters handle the neutral connection from what I've seen).

Like FilterGuy said in his docs though, I don't really see the problem with wiring it up as a common neutral. I had my EG4s set up that way before the firmware changes came out (I had removed the N/G bonding screw from inside of both inverters as well).