Ways to parallel 2 solar arrays into 1 mppt charger?

[lns]

I have an AIO with one PV input and 2 parallel solar arrays (each about 10A). AIOmppt charger is 27A max input. I also have 2 inline fuses for the 2 parallel arrays. I've seen a video of David Poz who just connect the 2 PV wires directly in the AIO's PV input. Is this a good idea? If I need to use a Y-connector, what gauge wires do I need for the Y-connector and the wire into the AIO charger?

Thanks!

 

[sunshine_eggo]

Piece of cake:

Amazon.com : mc4 splitter

 

[lns]

Piece of cake:

Amazon.com : mc4 splitter

what gauge wire do I need between these and the AIO ?

 

[sunshine_eggo]

Assuming it's not too long a run, 10awg will more than handle the ~20A.

 

[TorC]

You can use a fancy combiner box, but there's no reason to bother. Maybe slightly improper, but what I did with my earlier partial system was to run positive and negative each to a single gang junction box, and use wire nuts to tie into the wire that went to MPPT. That was ~80V, 20A, and worked fine. All 10ga wire.

People do put two wires under one screw quite often, and it seems to work, but AIUI, doing so is improper. As long as you take care to ensure both are well secured I don't expect any trouble from it, but I'm sure it is more susceptible to less than perfect workmanship.