200a main with sub 125a panel aio placement question

[SolarDrewT]

I currently have a 200a main feeding a sub 125a through a 125a breaker. I also have another 200a Main that Enphase is serving with that panels critical loads. No sub panel on the Enphase.

My goal: to put an aio inverter and connect 12kw of panels. Already have an interconnect with power company through an enphase set up on another 200a panel.

Plan: due to wallspace being better at the sub panel in a separate garage, my initial thought is to hook the aio in between the main and sub via the feeds from main panel then the aio to the sub panel via a 125a breaker

questions: is that a viable plan? once the aio is receiving solar power it would energize the sub panel then would it feed back to the main 200a and energize and any excess go back to power company like the enphaee set up?

Is there a better plan you have experienced? Picture of sub panel below

 

[timselectric]

questions: is that a viable plan? once the aio is receiving solar power it would energize the sub panel then would it feed back to the main 200a and energize and any excess go back to power company like the enphaee set up?

Yes
As long as it's a hybrid AIO.
And you don't exceed the backfeeding rules of your main panel.

 

[SolarDrewT]

Yes
As long as it's a hybrid AIO.
And you don't exceed the backfeeding rules of your main panel.

The 200a main x 1.2a is 40a backfeeding. It is a hybrid. Would you suggest that backfeed to be a 50a x.8 equals 40a?

 

[timselectric]

The 200a main x 1.2a is 40a backfeeding. It is a hybrid. Would you suggest that backfeed to be a 50a x.8 equals 40a?

40a maximum backfeeding a 200a main, is correct.

 

[SolarDrewT]

40a maximum backfeeding a 200a main, is correct.

My aio outputs 60a...what design would allow for that 60a to be output.

I've got emporia on that panel to learn and it looks as though 31a is the peak over the last month however if a design is better to get the 60a that would be something to consider.

Would that mean taking the mains from the 200a and connecting to the aio bypass of 200a then from aio to lugs?

 

[timselectric]

My aio outputs 60a...what design would allow for that 60a to be output.

I've got emporia on that panel to learn and it looks as though 31a is the peak over the last month however if a design is better to get the 60a that would be something to consider.

Would that mean taking the mains from the 200a and connecting to the aio bypass of 200a then from aio to lugs?

It would require a line side tap.
The AIO input, would have to be connected ahead of the 200a main breaker.

 

[SolarDrewT]

Appreciate your continued support and knowledge.

Got it. So I would kill the house power, test to ensure, remove the lug feed and attach to inverter and feed the lug from the inverter.

This is where I stopped because if the inverter failed I've got no power to that panel.

I think I like the other way...it just limits amperage.

Don't mind the emporia mess.

 

[SolarDrewT]

There are Polaris installed if that is useful...

 

[Quattrohead]

Gridboss is now a certified PCS unit that removes the 120% limit rule.

 

[SolarDrewT]

Gridboss is now a certified PCS unit that removes the 120% limit rule.

Yeah I wish the gridboss had been around when I started with Enphase. This other panel I'm working on is dead in a power outage. And it has some circuits that I would want that didn't fit in the Enphase critical loads.

Without further expense I think the 40a will be enough as it stands. Just wanted to further explore the 63a output abilities...don't think it's necessary to cover the circuits I want now to satisfy my addiction of more solar and and getting rid of the rest of my power bill.

 

[timselectric]

There are Polaris installed if that is useful...

If there's an open lug in the Polaris connectors, you can connect the inverter there.
The feeder comes in to the Polaris connectors, and out to both, the 200a main breaker and the inverter input.
That's a line side tap.

 

[timselectric]

Gridboss is now a certified PCS unit that removes the 120% limit rule.

The 120% limit doesn't apply to anything ahead of the main.
The 120% rule only applies to the panel bussing.

 

[SolarDrewT]

Well I guess I just got a little smarter and can get more amperage out of the inverter if the sp production is there. Here is to clear skies.

 

[SolarDrewT]

From the manual...
Maximum bypass phase overload current 2pole, 63A/63A(L1/L2).

If I were to connect via the Polaris on my 200a panel, do I need a fused breaker or any protection to prevent more amperage to the inverter...

that is 60a or 70a? Or is that 126a so a 125a?

 

[timselectric]

If I were to connect via the Polaris on my 200a panel, do I need a fused breaker or any protection to prevent more amperage to the inverter...

No OCP needed, if less than 10' of wire.
It's self limiting. But a way to disconnect it will come in handy.

that is 60a or 70a? Or is that 126a so a 125a?

Anything above 63a is fine. Size your conductors the same.

 

[SolarDrewT]

No OCP needed, if less than 10' of wire.
It's self limiting. But a way to disconnect it will come in handy.

A manual throw switch sounds like a plan.

Anything above 63a is fine. Size your conductors the same.

Great I have the gauge charts. Spot on advice and great to have some new beginner confidence...

 

[SolarDrewT]

So I'm reviewing the manual and in this picture it appears that there are 2 grounds and 2 neutrals. From my learning this seems incorrect and only one set of grounds and neutrals back to the panel bus bars is what I have seen.

Any input?