Generator or Inverter Neutral downsize?

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klaatu

klaatu

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With a Generator connected off the main panel at a distance, can the neutral be a smaller AWG than the Line conductors?
Same question with regard to a solar inverter.

What about when there are multiple inverters in parallel, each feeding to the main panel and terminating in a separate breaker.... can/should the neutral be shared? ❓
 
Need more detail. What is the load on the neutral in the generator application? Is the solar inverter a grid-tie application or not?

In the most common applications the generator question is going to be a very different question than the solar inverter question.
 
The Load on then gen is a single family home....typical mixture of loads

Inverter(s) are grid tied
 
Theoretically the generator neutral can be sized for the unbalanced load, but not smaller than the EGC. But I never seen this done in residential and it's arguably not worth it.

For the solar inverters, check the inverter documentation and see 705.95(B) in the 2017 NEC (or 705.28(C)(2) in 2020, same thing).

You cannot share a neutral among multiple inverter circuits. If they were combined in a subpanel then the neutral to the subpanel can probably be smaller.

If these things are on the same building, be sure that the solar cannot connect to the generator. Typically that's by connecting the solar on the line side of the transfer switch.
 
jaggedben said:
You cannot share a neutral among multiple inverter circuits. If they were combined in a subpanel then the neutral to the subpanel can probably be smaller.
Click to expand...

I found out that the inverter is designed in such a way as to not have current on the Neutral....its more of a sense input.
Hence multiple inverters in parallel each with their own neutral would be a waste. Seems to me this is a perfect situation for sharing a neutral, though its not clear if NEC allows this or not. It would seem it would allow it since current = 0, or milliamps at most.
I have a clamp-on on the neutral and I can confirm current is ~zero.
 
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