Neutral connection wiring for offgrid inverter with sub panel

[fabieville]

Where do you run the neutral connection from that goes to the inverter output? Do you run the neutral from the main panel disconnect or do u take the connection from the sub panel? Does it matter where it comes from seeing that its the same neutral in the main box that ties back with the one in the sub panel?
I have a off grid set up with a Main panel, sub panel and a transfer switch. I have 2 hots coming from the grid, sub panel where all my loads are and from the inverter going to my transfer switch but in regards to the inverter neutral connection should i run the neutral from the main panel box or take the connection only from the sub panel?
The neutral and ground bars are tied in the main disconnect box.
Running it from the main panel disconnect would be a shorter run to the inverter than taking it from the sub panel so i would use far less wire.

 

[mondurr]

It depends on the inverter and your transfer switch. Does your inverter have a common neutral and does your transfer switch switch the neutral? The answer to the latter is probably no, so it comes down to whether or not neutral input on your inverter is the same as neutral output. If your inverter is a low frequency inverter without an input neutral, you likely want to avoid connecting its output neutral to grid neutral, in which case you need a transfer switch that switches neutral.

 

[fabieville]

My setup is a 220v high frequency hybrid inverter with input and output connections. But I don't use the input port which takes in L1, L2 and grounds. Instead I feed the output to a step down transformer to produce 120v. Then I feed the transformer 120v output to the inverter side on the transfer switch and then I connect the L1 and neutral coming from the main panel disconnect to the grid side of the transfer switch and then I connect the sub panel L1 and neutral to the load side of the transfer switch. My sub have all my load breakers.

My main panel disconnect with just the breaker for the grid alone is located close to my solar setup .Therefore can I use the neutral from it to connect to the load neutral slot on the transfer switch???
Instead of running a 30feet neutral wire from the sub seeing that the neutral in the main panel disconnect is the same like in the sub.

I am only using 1 phase 120v that's why i am only working with the L1 & N from the grid and the L1 and N coming from the step down transformer.
Please note that the neutral and grounds are tied only in the main panel disconnect. Which setup is the correct one and will the switching of the transfer switch to either solar or grid goes smoothly without any issues?
Please note the transfer switches only 2 legs at a time. Either L1 and L2 or L1 or N

 

[mondurr]

sorry this is above my pay grade, but a diagram may help others chime in. I think you’re ok as long as you do not connect the inverter neutral to grid neutral.