Hi there

I have had some bad luck with installers... so looking to get some advice here before I approach one more... (first installer wired inverter incorrectly and I had no earth leakage, second installer wired panels weirdly as described in this post, and has now gone bankrupt and I can't get hold of them to fix).

I have an 8kw Sunsynk inverter with 18 JA Solar 550 panels

The 18 panels are spread out on my roof as attached in the pic.

Array A is 12 panels, and Array B is 6 panels. There is probably room for 1 more panel on the NW facing roof, and probably 2-3 more panels on the NE facing roof. The other parts of my roof are no-go because of shape, other parts of the roof not pictured here joining in at angles, etc etc).

My installer has gone bankrupt - so I'm unable to ask them... but it seems to me like they wired the panels with the 6 NW panels and 3 NE panels in series on MPPT1, and the other 9 NE panels in series on MPPT2. The reason I think this is because in full sun with low load and batteries fully charged, both MPPTs have almost identical voltage of around 400v.

Assuming this is true, I'm guessing this is not optimal (I've read you shouldn't mix panel directions in a single string)? What would be better? Should I do the 12 NE panels set up as 6S2P on MPPT2 and the 6 NW panels as 6S1P on MPPT1? Would this make a significant difference, or not worth the effort?

I'm also considering adding in 3 more panels, 1 more NW and 2 more NE, and then since they're up there, they could rewire to 7S2P and 7S1P. I think I may get some current clipping (not sure if the 8kw Sunsynks are capped at 20, 22 or 26A these days - I've seen all three mentioned...), but this is probably okay.

What do you guys think?

And then - does anyone have a suggestion for an installer in Cape Town (Durbanville to be precise)? One that isn't likely to go bankrupt soon so I don't lose any and all support...

Edited October 19, 2025Oct 19 by gu3st

Contact @TaliaB, hopefully he has availability to do the install.

7S2P and 7S1P is good. Definitely better than what the installer did. Panels in different directions on one string in series won't work well.

Edited October 20, 2025Oct 20 by abd7

it makes perfect sense to connect each array to different MPPT, the 2 arrays don't have to be at the same voltage

On 2025/10/20 at 5:41 AM, abd7 said:

Contact @TaliaB, hopefully he has availability to do the install.

7S2P and 7S1P is good. Definitely better than what the installer did. Panels in different directions on one string in series won't work well.

+1 for @TaliaB He is back in SA but not sure if on leave already.