diy solar

diy solar

Need help tweeking my system and fixing issues

Daveyclimber

New Member
Joined
May 2, 2021
Messages
65
I just brought my new system online a few days ago and am trying to learn it's quirks and become comfortable with it. I live in western Montana where the sun doesn't shine much in the fall and winter.

6 panels installed on 12/12 pitch roof of my solar shed . They are q cells 350 watt panels. They are currently in operation
12 more identical panels will be installed on top of pole mounts in the near future as concrete can be afforded

There will eventually be 3 seperate arrays, each facing slightly different directions from east to southwest.

1 Growatt 48120 250v Mppt charge controller, currently running the 6 panels
1 Growatt 12000T 250v Inverter. It will run the 2 pole mounts
6 EG4 Lifepower batteries
7.5kw Diesel generator for grid charging and pass through. Totally off grid here

I am having issues with the inverter not closing the dry contacts to start the generator reliably. I have only been able to get it to do so on one occasion. The inverter is set up to switch to grid at 51 volts and back to battery at 54.5 volts.

Why does signaturesolar state to charge these batteries at 58 volts? I have never been able to charge beyond 55.4 volts before the inverter cuts charging. I have an EG4 charger and it will not charge beyond 54.6 volts. As soon as I reconnect the batteries to the inverter after charging with the EG4 charger, battery voltage drops to 53.4 volts. Is that normal?

Displayed battery voltage if differing between my charge controller and inverter. The inverter will typically read .2 volts higher and occasionally. 5 volts higher than the Scc. The Scc Displayed voltage is accurate and correct verified with a DVM.

Why does my Scc always read battery 100% full? Never changes.

Can't set battery shutdown setting 21 on inverter above 48 volts. Normal?

My inverter settings
1) SBU
2) 120 amp combined charging grid/solar
5) USE
11) 60 amp grid charging
12) grid charging cut in 51v
13) grid charging cut out 54.4v
14) CSO
19) 56.4v have tried up to 57.4
20) 56.4v
21) 48v

Scc settings
1)120 amps
2 USE
5) 56.4
6) 56.4
7) 48

Panel specs
350w
Isc 10.79
Voc 40.73
Impp 10.27
Vmpp 34.07
Current 6 panels are 3s2p
Future panels will be wired the same unless I can acquire 4 more identical panels.

Thanks for your ideas and wisdom!
 
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