Off Grid with Growatt!

[Lukowski]

Hello all,

Well I am preparing to put my system together once I gather all the necessary components.
Looking at getting some 395w jolywood bifacial, and run those 4s3p in two strings. (9480w total, overpaneling by 35% OR maybe I will get another mppt...and/or stagger the east to west sun 50/50)
Only picked these because its the highest capacity local panel out there for a reasonable price ( no benifit from the backside)
On order, off the coast of sweet sweet california somewhere, is a Growatt 12kw 250v 7000wk unit with my name on it.
Also embarking upon the shipyard should be three jakiper 48v LifePO4 batteries.

All that aside, there are some things to consider.
First, I do have grid power available at 100amp service but I plan on just running pass through from a sub panel in times when there is no sun.
What I want to do is run the AC output of the inverter to the circuit panel of the building. What is the preferred method of doing this?

Im thinking a 'main breaker' panel would make more sense, but I guess it really doesnt matter. IF I get a larger panel AND its a 'main lug', I just wont use the lugs.. What size breaker/wire do people use for their output from the inverter?

As far as the array goes, I do believe I am on the right track but still some un certainty with a couple things.
Like I said 4s3p is 30amp at 200v . From what I understand, without a combiner box, I need to put mc4 20amp (panel rating) fuses on each series string, and then after i parallel, that string is going to pass through a DC disconnect at the array. Using 150ft of 8awg thhn to run inside and pass through a dc 32amp breaker and into the 2 pv inputs.
I've got 2 places I intend on sinking a grounding rod: at the array; and at the indoor panel. Do those 2 grounds need to have continuity by means of an additional wire to run from the array to the panels?

Is there any other safety Compenents I may be missing? The batteries have built-in breakers. The array is grounded, has fuses, breakers. And the panel will be grounded.

Additional info:
Jolywood
395W
VOC 49.03V
Isc 10.31amps

located in Georgia, USA

 

[MrM1]

I'd probe get the 2nd SCC. I have been round and round about over paneling the Growatt SPF T12000 DVM we are going to install in a few months. After growatt respond to another user saying 7000w is max we just Decided to go with 2 SCCs. We have 32 370w panels. Going 2 SCCs each with 2 inputs allows us to have 4 4s2p arrays so we don't have to fool with combiners or fuses. So going the 2nd SCC really did not cost that much after u deducted the price of combiners and fuses we were buying.

 

[Lukowski]

I'd probe get the 2nd SCC. I have been round and round about over paneling the Growatt SPF T12000 DVM we are going to install in a few months. After growatt respond to another user saying 7000w is max we just Decided to go with 2 SCCs. We have 32 370w panels. Going 2 SCCs each with 2 inputs allows us to have 4 4s2p arrays so we don't have to fool with combiners or fuses. So going the 2nd SCC really did not cost that much after u deducted the price of combiners and fuses we were buying.

Ok good to know, that sounds like the way to go. I was actually following your thread about the growatt.
I guess with the second SCC you still need to run DC breakers and in line fuses, right?
I was just gonna go with the 7kw max input in panels, but I think the more panels I incorporate from the beginning the happier I'll be.
The hard part is getting the exact amount of panels you want to use in the configuration that your doing with sellers the way they put limitations on the amount of panels they want to sell !!

 

[MrM1]

Ok good to know, that sounds like the way to go. I was actually following your thread about the growatt.
I guess with the second SCC you still need to run DC breakers and in line fuses, right?
I was just gonna go with the 7kw max input in panels, but I think the more panels I incorporate from the beginning the happier I'll be.
The hard part is getting the exact amount of panels you want to use in the configuration that your doing with sellers the way they put limitations on the amount of panels they want to sell !!

If you only run 2 parallel stings per pv input you don't need beakers /fuses or combiner boxers. You want a switch to turn off the array. Different vendors have external pv switches

I plan to use 4 Breakers as switches in our electrical room/solar shed. They will b sized for the load , but will function mostly as on/off switches.