Series-parallel or parallel-series, does it make a difference? How?

[Boomerweps]

Does it make a difference whether solar panels are connected in series first, then series strings in parallel OR parallel first, the paralleled groups in series? Advantages and disadvantages? I understand parallel is best avoiding shading while series is better for low light power generation to reach MPPT voltage minimums.

 

[Supervstech]

The more panels you place in parallel the more fusing is needed. 2 or less no fuses needed.

 

[Supervstech]

I would always connect the series strings first, then parallel those.

 

[Boomerweps]

I’m now thinking I’ll run two pairs in series first, then parallel them, mostly to save on parallel adapters. That way the 100W panel specs would result in 50V and 9A feeding a 100V/30A EPEVER. To me, that’s well within controller tolerances. I think I could add a bit more panels, even though the controller manual charts 390Watts maximum solar panel input.