6.7Kwh 8S2P system what is better approach

[LakeHouse]

i'm still having issues with the 8s2p, the voltage will exceed the inverter 450V, i have order another same inverter, would that help ?

What options do i have here?

Maybe I missed someone else mentioning this... You don't need to a fuse for each panel. In fact, for two strings in parallel, you don't need any fuses on your PV at all. But if you are going to fuse those strings, use one fuse per string.

 

[talk2abs]

You can connect them in parallel to double the output. And gain a second SCC for more panels.
Or just save it as a spare, if you don't need it right now.

@OffGridForGood @timselectric
Hi, do you have a diagram of how they can both can be connected in parallel and to 1 battery:", so in my case, 2 inverters ( in parallel) and 1 (48V battery)

I have seen some videos where they are connected in parallel but non of them is actually showing connection to 1 battery, does that mean only the Main inverted get connect to the battery?, while the AC output of the second inverter connect so the sub-panels?

 

[talk2abs]

Hi @OffGridForGood & @@timselectric, So i'm wondering if you have any diagram or video link describing how to connect two inverters (connected in parallel) to one 48V battery.

I like the more output of a second inverter but i only have one battery, most of the videos i have seen were not even showing how to connect 2 inverters to one battery if it should be or it's just the master inverter that should be connected to the a battery.

 

[OffGridForGood]

Hi @OffGridForGood & @@timselectric, So i'm wondering if you have any diagram or video link describing how to connect two inverters (connected in parallel) to one 48V battery.

I like the more output of a second inverter but i only have one battery, most of the videos i have seen were not even showing how to connect 2 inverters to one battery if it should be or it's just the master inverter that should be connected to the a battery.

Typically the inverters will connect to a bus bar (one for pos one for neg)
I like to put a shunt on the neg to the it's bus, and beside this a Class-T fuse on the Pos
The batteries feed to each bus (pos to pos, neg to neg)
Your inverters will have a diagram in the manual about how to set them up in parallel - settings to program, comms between them, cables to the pos bus, and neg bus.

 

[LakeHouse]

Hi, do you have a diagram of how they can both can be connected in parallel and to 1 battery:", so in my case, 2 inverters ( in parallel) and 1 (48V battery)

You don't have enough battery to get much advantage out of this for the AC side. The maximum output current of your battery is 120A, which at 50V (about the lowest you want to run the battery), is 6000W. Your single Growatt puts out 5000W, so adding another won't get you much more power, but will double your idle draw.
If the intent is just to use the second Growatt as an SCC, that might have some benefits if it functions as an SCC with the AC side turned off (as many but not all AiO's do).

 

[talk2abs]

Hi thank you for the response, i think i will just keep the second inverter then, what is an SCC ( second charge controller) ?

 

[timselectric]

Hi thank you for the response, i think i will just keep the second inverter then, what is an SCC ( second charge controller) ?

Solar Charge Controller

 

[TomC4306]

Why is the battery connected like that to the panels

Huh?
What diag you looking at

 

[TomC4306]

, do you have a diagram of how they can both can be connected in parallel and to 1 battery:", so in my case, 2 inverters ( in parallel) and 1 (48V battery)

Using bus bars as the interconnection point for everything.
Batteries, to the bus bar.
Inverters, to the bus bar.
Chargers, to the bus bar.
Bus bars circled in picture.

Blue Sea Systems 2127 250 Amp MaxiBus BusBar with 4 studs https://a.co/d/7bNNP0S

 

[talk2abs]

Using bus bars as the interconnection point for everything.
Batteries, to the bus bar.
Inverters, to the bus bar.
Chargers, to the bus bar.
Bus bars circled in picture.

Blue Sea Systems 2127 250 Amp MaxiBus BusBar with 4 studs https://a.co/d/7bNNP0S

Fantastic thank you so much

 

[talk2abs]

@TomC4306, and thank you so much, i just got back from the installation site, the system is expected to get generate 6.7kwh power but its only generation 2.0kwh, so what could have being done wrong ( either from wiring side or inverter configuration), any idea would be help, 2kwh is too low to even power by AC unit without pulling from the battery at peak period

 

[OffGridForGood]

what was the weather like?

 

[talk2abs]

The weather is a abit cloudy, 27 Celcius, i was thinking maybe the wiring connection btw the panels the team did was wrong, the design i gave them was 8s2P, not 100% sure if they did that exactly, because it only producing 29% of the 6.7KW system.

At peak its only producing 2000W, how is possible to loose over 70% of the system capacity?

Design 16 Panels at 420W

 

[TomC4306]

1. Solar panels almost never make their rated power. Even a high cirrus layer degrades my peak by ~20%. Clouds and shadows kill solar.
It is not just daylight but direct sunshine striking the entire face of the panel that makes power.

2. Solar array peak power is normally only achieved when the sun is at 90⁰ to face of the panel in both axes. (Tilt for season, noon)
Where are your panels mounted and where are they aimed. Are you north or south of the equator?

3. Wiring and connection issues. Small gauge wire, bad crimps, loose connections, etc
Did you torque all of the connections with a calibrated torque wrench?

4. Charger settings. In the settings of most chargers one can limit the charge from grid and solar.

I have 5910 watts peak of panels (used)
I am at 39⁰ north latitude.
My panels are ground mounted and tilted at 39⁰ from flat. (set for the equinoxes).
From about April to September my array can produce 30,000 Watt hours (30 kWh) per day.
Notice I said CAN produce.
The panels will not make power if there is nowhere to put it. If your battery is full and you have no loads, solar output is zero.

Edit.. just went back and looked at picture 1.
Cloudy. Battery almost full, still taking 500
watts. Loads of 400 watts. PV making 1000 watts.
Looks correct.

 

[OffGridForGood]

how is possible to loose over 70% of the system capacity?

The weather is a abit cloudy,

Could be as simple as this.