200A panel to 200A subpanel

[GarySaf]

Would this be up to code.
Sol Ark 15k load side to 200A critical panel A.
200A breaker on this critical panel A feeding another 200A subpanel B.

If that is allowed, then can I still have more breakers on critical panel A?

Here's what i'm trying to think through:
I have a 400A main panel, that has a 200A breaker feeding the subpanel B to the house.
The main panel also has a bunch of other breakers but some important incase the grid went down, such as garage and well pump.

I'd like to move the 200A house breaker and anything important to another panel that's fed by something like a Sol Ark.

 

[timselectric]

As long as all wiring is sized for 200a, then yes it's fine.
Everything will be protected/ limited by the first 200a breaker.

 

[GarySaf]

Thanks - yes all wiring is sized correctly.

Other thought; I know the Sol Ark can pass 200A, but how would you handle a situation such as this with something like the new Midnite AIO? It’s not that the house subpanel uses 200A but it’s just the one wire that goes to it and hard to change the way the wiring is done.

 

[Hedges]

It can pass through 200A, but what good does that do you?
If grid goes down and load exceeds what SolArk can supply, you might as well not have SolArk there because it will instantly shut down, taking critical loads with it.

Any panel that will sometimes have more loads than inverter can feed, don't have normally fed through bypass.
Feed it direct from grid, and have interlocked "generator" breaker you can switch to feed important loads from inverter, following grid failure, after manually switching off excessive loads.

I like to have load-shed relays so critical loads always powered, backed up loads powered down to say 30% SoC, less important loads powered down to say 70% SoC.

Midnight has several relays and breakers to support such shedding, I think. I install them externally for my SMA.

 

[GarySaf]

It can pass through 200A, but what good does that do you?

Coz I’m taking the 200A breaker out of the main panel fed by the grid and moving it to a separate panel that has the other 200A breaker feeding the house?

Am I missing something?

Main panel is 400A. Add 200A breaker from main panel to grid input of Sol Ark (not set on Sol Ark)
Load side of Sol Ark (or whatever else) feeding a 200A critical panel and 200A breaker from this panel to house panel.

 

[GarySaf]

Any panel that will sometimes have more loads than inverter can feed, don't have normally fed through bypass.

breaker you can switch to feed important loads from inverter, following grid failure, after manually switching off excessive loads.

I get that and will plan to size the inverter (and battery backup) appropriately. For now, it was mainly to be sure that I can use the 200A to the house and be sure the wiring I'm thinking would be up to code.

If it comes to manually turning of excessive loads, I could aways do that at the house panel too, I suppose.

 

[timselectric]

Thanks - yes all wiring is sized correctly.

Other thought; I know the Sol Ark can pass 200A, but how would you handle a situation such as this with something like the new Midnite AIO? It’s not that the house subpanel uses 200A but it’s just the one wire that goes to it and hard to change the way the wiring is done.

It's no different with any hybrid AIO.
A 200a Passthrough just simplifies the installation.
It can help reduce your bill, but is very limited for a backup situation when the grid goes down.
Personally,
I wouldn't connect any loads through an AIO, that it couldn't handle.
As stated above, when the grid goes down, the inverter could also shut down from overload.

In simplest terms.
A 200a Passthrough on a 50a inverter is useless.

 

[GarySaf]

It can help reduce your bill, but is very limited for a backup situation when the grid goes down.
Personally,
I wouldn't connect any loads through an AIO, that it couldn't handle.

Thank you - If there's a better way I can think of getting critical loads wired to the house, I agree and would do that.
But the house if 100' away from the main panel and has a just the one 200A breaker and wiring to it and for now just trying to think through different scenarios.

At the peak the continuous loads aren't ever over 10kWh, but I appreciate the inverter needs to be sized appropriately to handle loads and surges.
With what's involved with the way it's wired, I would rather even have 2 x Midnite AIO (or equivalent) to ensure the inverter part isn't the limiting factor and still need to figure out battery backup etc.