Series Connecting 100 watt Panels

[Fosse]

I have a Growatt 24V SPF 3000TL LVM connected to 12 x Renogy RNG-100D-SS 100 watt panels.

What in your experience is better? 3 x 4 panels connected in series or 4 x 3 panels connected in series?

Thank you!

 

[Rednecktek]

Well, 4 panels would only be about 80v so still well within your Max VoC limit. Doing a 4s3p would mean less wire runs and still let you rotate strings for early/mid-day/late sun if you wanted. In theory you COULD maybe do a 6s2p, but that might be pushing it.

 

[Fosse]

Well, 4 panels would only be about 80v so still well within your Max VoC limit. Doing a 4s3p would mean less wire runs and still let you rotate strings for early/mid-day/late sun if you wanted. In theory you COULD maybe do a 6s2p, but that might be pushing it.

"Pushing it" how? Amp wise?

 

[Rednecktek]

Volt wise. When you're mathing out your strings you add the VoC rating of each panel together for the total voltage. Those 100w panels are usually in the 20-ish VoC rating, so 6 would be about 120v-ish. Add 20% fudge factor for really cold weather and you're somewhere in the 145v-ish range which is the top end of what that unit can support.

EDIT: Looking at the specs it's 22.3VoC for the panels, 6s would be 134v (still within the 145 happy range) but if it gets really cold you could get as high as 161v (too high!) which would be too much. How cold does it get where you live? Below freezing? WAY below freezing? Just barely freezing? Never that cold?

 

[Zwy]

I have a Growatt 24V SPF 3000TL LVM connected to 12 x Renogy RNG-100D-SS 100 watt panels.

What in your experience is better? 3 x 4 panels connected in series or 4 x 3 panels connected in series?

Thank you!

4S3P

I have 6 100w panels currently on my truck camper. Due to some space constraints and possible shading, I went 2S3P but might change to 4S2P when I remove the roof ac and add to more panels. It works well with 2S3P, I did use a combiner box with fuses and breakers.

 

[Fosse]

Volt wise. When you're mathing out your strings you add the VoC rating of each panel together for the total voltage. Those 100w panels are usually in the 20-ish VoC rating, so 6 would be about 120v-ish. Add 20% fudge factor for really cold weather and you're somewhere in the 145v-ish range which is the top end of what that unit can support.

EDIT: Looking at the specs it's 22.3VoC for the panels, 6s would be 134v (still within the 145 happy range) but if it gets really cold you could get as high as 161v (too high!) which would be too much. How cold does it get where you live? Below freezing? WAY below freezing? Just barely freezing? Never that cold?

Sorry I miss read that as 6 x 2 in series. My bad

 

[Rednecktek]

Sorry I miss read that as 6 x 2 in series. My bad

300v? What could go wrong?

 

[Fosse]

300v? What could go wrong?

Right! Considering what we pay to have this stuff its best to know what we are doing. I am aware of the voltage limits of charge controllers but I do appropriate the heads up.