400 Amp Grid Tie - Is this setup possible?

[austinhutchins43]

I am looking to install a 400 AMP service on my house that we are building and supplement it/back it up with a complete hybrid grid-tied solar system. Looking to achieve this through 2 of Sol-Ark's 15k Hybrid Grid-Tie inverters. My 400 AMP meter base will feed 2 separate 200 AMP disconnects (one for the main house, one for the garage and bonus/man room above and any additional outside power sources we need for the future like pool, kitchen, etc).

My question is the setup, I am thinking that with the Sol-Ark's capabilities I have it thought out correctly but there are many more experienced and knowledgeable people on this site than myself. I am thinking that I would go from the disconnects directly to the grid bar in the inverter, then from the inverter out to each 200 amp panel. This is the normal setup for a standard 200 AMP service with just one panel and inverter so I am thinking I would just duplicate it correct? And run the batteries for the battery power in parallel then attach to both inverters?

Also I have the solar arrays separated to go to each inverter, but could I potentially combine all panels and just connect to both? Idk if that is safe or could be done to maximize the output to each sub panel or not. Excuse my excel drawing but I attempted to illustrate as best as I could to show what my thoughts on the setup would look like. Please point out any flaws.

 

[going_commando]

I don't know the answer to your question, but check out Engineer775 on youtube. He's done a ton of solark installs including on 400 amp services.

 

[timselectric]

. I am thinking that I would go from the disconnects directly to the grid bar in the inverter, then from the inverter out to each 200 amp panel. This is the normal setup for a standard 200 AMP service with just one panel and inverter so I am thinking I would just duplicate it correct? And run the batteries for the battery power in parallel then attach to both inverters?

Yes

Also I have the solar arrays separated to go to each inverter,

Also correct

but could I potentially combine all panels and just connect to both?

No, you would actually get less power.
Because the two MPPT's would fight for control over the circuit.

 

[austinhutchins43]

Yes

Also correct

No, you would actually get less power.
Because the two MPPT's would fight for control over the circuit.

Awesome, you're the man. Thanks!

 

[Jose_Sol-Ark]

Hi @austinhutchins43 , I was reviewing your diagram and noticed that the load outputs of the inverters are separated. If the inverters are configured to operate in parallel, their outputs must also be combined. Additionally, I suggest using a transfer switch, for using grid instead of inverters if necessary. I think the diagram 8 could be similar to what you need, but with two electrical panels.

 

[austinhutchins43]

Hi @austinhutchins43 , I was reviewing your diagram and noticed that the load outputs of the inverters are separated. If the inverters are configured to operate in parallel, their outputs must also be combined. Additionally, I suggest using a transfer switch, for using grid instead of inverters if necessary. I think the diagram 8 could be similar to what you need, but with two electrical panels.

View attachment 238666

What would that diagram need to look like to supply 2 separate 200 AMP panels? There would be a 400 AMP main feeding two 200 amp sub panels. Does Sol-Ark have a diagram for 400 AMP configurations? 400 AMP new constructions are becoming much more frequent in today's world, I would love for Sol-Ark to supply a diagram to take the guess work out of this.

The only thing wired in parallel are the batteries to the inverters, everything else technically is two different solar systems. Would the same parallel rules still apply?

I agree on the transfer switch in the instance of needing to bypass the inverter for maintenance or replacement, I can try to add that to my configuration but if you could help on the above that would be awesome.

 

[austinhutchins43]

Hi @austinhutchins43 , I was reviewing your diagram and noticed that the load outputs of the inverters are separated. If the inverters are configured to operate in parallel, their outputs must also be combined. Additionally, I suggest using a transfer switch, for using grid instead of inverters if necessary. I think the diagram 8 could be similar to what you need, but with two electrical panels.

View attachment 238666

I think I have it figured out to have them functioning in parallel. Here is an updated version of what I came up with. Again, just an excel program I am creating this on so it wont show all the intricate connections and additional wiring I know it needs (i.e. cat 6, neutrals, grounds, etc). Can you let me know if this is how it should be connected?

 

[neo2299]

I have 400amp with two eg4 18kpv. To combine loads I did a 400amp shut off

 

[2048sunpower]

I have 400amp with two eg4 18kpv. To combine loads I did a 400amp shut offView attachment 238926

Do you have a full diagram?

I think I have it figured out to have them functioning in parallel. Here is an updated version of what I came up with. Again, just an excel program I am creating this on so it wont show all the intricate connections and additional wiring I know it needs (i.e. cat 6, neutrals, grounds, etc). Can you let me know if this is how it should be connected?

View attachment 238893

What type/brand 400A combiner box did you get / are you looking at?

 

[2048sunpower]

Do you have a full diagram?

What type/brand 400A combiner box did you get / are you looking at?

This was what I received from EG4 for a 400A service install with multiple inverters. Still looking for combiners.

 

[Kazoo]

I think I have it figured out to have them functioning in parallel. Here is an updated version of what I came up with. Again, just an excel program I am creating this on so it wont show all the intricate connections and additional wiring I know it needs (i.e. cat 6, neutrals, grounds, etc). Can you let me know if this is how it should be connected?

View attachment 238893

Piggy-backing off this thread:
I'm also looking into doing 400 amp service and near 400 amp backup / off-grid power. This idea (with more inverters) seems ideal functionality-wise. My gripe is that 400 amp panels and combiners and equipment are few and far between and very expensive.

The idea I'm thinking of uses 2 GridBOSS's, 6 FlexBOSS's, and EG4 wall mount batteries (probably 8?). In a recent interview the CEO of EG4 slipped in that you could use a common battery bank in such a system which would be absolutely perfect.

The only issue I'm running into with that design is how the communication would work. As far as I'm aware there can be only one master battery that talks to only one master inverter. (Each 3-inverters and 1-gridboss is it's own completely separate system, which I'm okay with because 400-amp services usually power two 200-amp panels anyway). Here are my ideas in order of preference:
1) The big parallel battery bank can talk to both systems of inverters to share it's charge % and other details (maybe not possible?)
2) One of the systems of inverters doesn't have communication, but uses battery voltage instead
3) Communication-wise, there are two sets of batteries, one for each inverter system, but they are still in parallel with bus bars
4) There are two completely separate battery banks (leading to a situation where the house is out of juice but there's plenty left in the garage/shop's reserve)
EDIT: 5) No communication with batteries

Thoughts?

I suppose if the grid is up, one system's output could go from it's output to the other's input (through the meter almost) but that connection wouldn't be there in a grid-down situation

 

[Penryn87]