@42OhmsPA Are you running the NE Solar 370W panels to the MPPT's?
Originally I had planned on 20 or 21 panels for the large array using 1/2 of the used tornado damaged MT Solar mounts I bought cheap. Configuration was landscape 4x5 with the odd panel somewhere if I used 21 panels. 7S configuration, 3 strings or a pair of 7S and one 6S.
Over the weekend I started to build the base for the array, poles have been in over a month and I just finished the video highlights of that today. Originally these mounts were single pole with 3x5 configuration. I'm using 2 poles and planned on the 4x5. But after getting the center frame sections all bolted together I thought I can add a wing on each end and have 5x5, so 25 panels total. The wings are extras as I combined the mounts and these would have been on the ends, I only have to bolt them on. I had some concerns with clearance on the sides for moving equipment past the array and that is why I originally planned on only 22.5 feet width, the added 3.75 feet long wings will add 7.5 feet.
With 5x5, that means most likely one 7S string and three 6S strings. My question is about combining probably a pair of the 6S and what you have been running for MPPT strings. 9S would put me over on VOC when it is -30°F here, 8S would work but what about the extra panel? 7S works for single strings but overpanels the MPPT if combining 2 parallel strings (and you know what I think about over paneling if you have enough MPPT's) but only 180W of over paneling so not a big deal. 6S with 2P to one MPPT works out well and leaves one MPPT still open with one 7S and the other 6S each using one MPPT.
How did you run your strings?
I'll still have 6 panels left, will have to buy more panels to use those up.