Three EG4 6000XP's Wiring (Please Review)

Greetings.
I’ve taken the off-grid conversion plunge and am in the process of converting my home electrical system. I plan on running three 6000XP’s, with room for a fourth if need be. Here’s the wiring diagram I’ve come up with. Thanks to solarenvy's thread for a good example to start from.



I plan to use an interlock switch instead of a transfer switch. The interlock will be connected more-or-less in reverse to how I normally see them used. This way I can run a full 200amp passthrough via four inverters, and can still have stand alone grid access if I need to do some work on something.


A few things I’m wondering about during possible future code inspection:

-1- Will the inspector be ok with no main breaker in the Inverter Combiner box? (There’s a 200 amp breaker on the load panel. And I believe all wires are protected in a shorting event)

-2- Is it necessary to run a neutral line to the Inverter Combiner box? I can’t think of a reason to.



The system will have roughly 11kW of solar and a 43kWh diy battery bank. I will likely charge off the grid at night and run mostly grid-free during the day if I can still find a free nights and weekends plan.



Criticism is welcomed.

1) I'm not certain but as long as there is a breaker between your loads and combiner box on either side you should be okay. However, I believe you will need a 150amp breaker in your Loads panel that connects to your combiner box. 200amp for the entire panel isn't protecting the conductors between your loads panel and your combiner.

2) Yes you must have both ground and neutral flowing through the combiner box and into your load panel. Then you must bind your neutral and ground at the main panel. Remember your neutral is your return, it must be there for the current to flow back to it's source.

For more details see, the 18K manual which has wiring diagrams for 2 or more inverters that will be nearly the same as your 6000 XP

Here is a three inverter diagram for Sol-Ark, it just like their diagrams better, they're a little less messy.

MaikaiLifeDIY said:

1) I'm not certain but as long as there is a breaker between your loads and combiner box on either side you should be okay. However, I believe you will need a 150amp breaker in your Loads panel that connects to your combiner box. 200amp for the entire panel isn't protecting the conductors between your loads panel and your combiner.

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The conductors between the loads panel and the combiner panel should be protected by the three 50 amp breakers in the combiner panel. If there is a short anywhere on those conductors the three breakers will trip.

MaikaiLifeDIY said:

2) Yes you must have both ground and neutral flowing through the combiner box and into your load panel. Then you must bind your neutral and ground at the main panel. Remember your neutral is your return, it must be there for the current to flow back to it's source.

Click to expand...

The neutral ground bond will happen in the main panel as shown on the wiring diagram. All other N/G bonds will be severed. As for running a neutral to the combiner box: The 6000XPs have only one neutral bus internally. Their input and output (neutral) is the same. So when you connect the 6000XP internal neutral bus to the main panel neutral bus it is the same as running another wire from the 6000XP to the loads panel. All neutral requirements from the loads panel will run through the 3/0 connection between the load panel and the main panel and then up to the 6000xp if need be. Why add another 6awg connection when you already have a 3/0 connection?

Any extra connection from the XP’s to the combiner to the load panel would just be a double/twin (superfluous) connection.

Burrito5000 said:

The conductors between the loads panel and the combiner panel should be protected by the three 50 amp breakers in the combiner panel. If there is a short anywhere on those conductors the three breakers will trip.



The neutral ground bond will happen in the main panel as shown on the wiring diagram. All other N/G bonds will be severed. As for running a neutral to the combiner box: The 6000XPs have only one neutral bus internally. Their input and output (neutral) is the same. So when you connect the 6000XP internal neutral bus to the main panel neutral bus it is the same as running another wire from the 6000XP to the loads panel. All neutral requirements from the loads panel will run through the 3/0 connection between the load panel and the main panel and then up to the 6000xp if need be. Why add another 6awg connection when you already have a 3/0 connection?

Any extra connection from the XP’s to the combiner to the load panel would just be a double/twin (superfluous) connection.

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I see what you're saying, honestly, I glanced at the diagram and didn't notice the neutral connected back through the main panel. Looks like what you have will work but for confirmation of NEC and local code you might want to have an electrician check your diagram, sometimes there are things that work and then there are things that have to be there no matter what and it's always a good idea to have a local electrician validate your plans prior to inspection.

Is it necessary to run a neutral line to the Inverter Combiner box

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I have a similar setup and through the thread below I did bring a neutral into the combiner box and I passed inspection. I brought it in so that I could pull a couple of 120v circuits for some test circuits that I did not care that they could be serviceable if the manual transfer switch had to be put in the grid position.