Adding two panels to 20 panel but on different roof

[jlrupert909]

I thought this would be easy to do myself since I've played around with doing my own work for years. I have a 20 panel system that is on a roof 4' up from a secondary/smaller roof. When I had the 20 panels installed I had them install rails for 2 more panels on the smaller roof so the rails are in place hence why I thought the hard part was over with. I bought two 255watt panels to compliment my candidan solar panels and two enphase 215m that match my existing 20 215 enphase inverters.

If you were standing with the sun to your back looking at the two roofs, you would see 20 panels to your 2 o'clock and 4 rails to your 10 o'clock that are 4' feet lower. Both face the same direction with the same tilt, etc.. The small roof is about 17' wide by 21' long. The existing 20 panels are layed out in landscape fashion. Because the rails are unirac and about 45" long it seems like I need to install the two additional panels in portrait.

So here is the first question of perhaps many if you all can endure. It may look a bit wierd having two panels portrait and the others landscape but is this a functional problem?

I have a bunch of other questions like do I make it one 12 panel string or two 11 panel strings and the conduit business and concern about the gauge wire so on and so forth.

Hopefully I've come to the right place and here is why. No one wants to deal with this probably because there just isn't enough money in it for them and that is fair, I get that. Some have said 4 panel minimum, etc.. So it seems like a DIY or nothing scenario.

Be warned though, like I said I have many questions.

[dnix71]

The panels need to be laid where they will catch the most sun and not shade each other. If that means 2 are laying down and the rest standing up, then that's fine. The sun's rays aren't polarized and the panel glass isn't either so the output won't be affected.

[ubud]

1. did you get the install manual?
2. need to know how existing array is wired, 1 or 2 meters, separate runs to main breaker box, ect.
3.maximum number of inverters per 20A breaker is 17 for the 215's
4.was system installed by you or someone else?
5. really need more information to give more help.
Please Advise
Frank

[jlrupert909]

Ok, I have the blue prints because I copied them from when they were installing. So this answers the other question, I did not install them myself. Two banks of 10 panels.

BANK #1 --> 10 x 250P panels --> 1 micro inverter each -->  JBOX --> conduit (3 x #10 AWG THWN + 1 x #8 AWG THWN-2 GND) --> SOLAR LOAD CENTER (2-Pole PV breaker 240 V 15 A)  --> another breaker.

BANK #2 --> 10 x 250P panels --> 1 micro inverter each -->  JBOX --> conduit (3 x #10 AWG THWN + 1 x #8 AWG THWN-2 GND) --> SOLAR LOAD CENTER (2-Pole PV breaker 240 V 15 A)  --> another breaker.

BANK #1 + BANK #2 inside SOLAR LOAD CENTER --> pass through another 2-Pole Main Breaker (240v, 25 A) --> AC Disconnect --> Main breaker panel --> Meter --> Grid

I hope this make sense. If not I'll figure out how to get an image posted.

[ubud]

ok the math says you can add 2 more inverters per string and still meet the NEC code for the
breakers you have in place.

my thoughts are to add one more panel+inverter per existing leg and you should be fine.

Your existing wire size and breaker size is good to go.

Frank