Correct Connections for Parallel Panels

[Michael_Grumbach]

Hi Folks,
I'm connecting (4) pairs of series panels in parallel.
I was planning on connecting pair one to pair two with a 2 in 1 out cable combiner, then connecting that output to the third pair with another 2 in 1 out combiner, then connecting that output to the fourth pair with another combiner.
This will take less cable than if I ran all four pairs to a 4 in 1 out cable combiner, but I don't know if there is a reason to go with the single 4 in 1 out over the multiple 2 in 1 out combiners.
Any experienced folks out there with thoughts on the matter?

[kazetsukai]

Assuming you're talking about the inline combiners, I guess there's little reason to distinguish. I'd suggest the best reason I can think of to go with (inline) 4-1 over several (inline) 2-1 is that as you combine more and more runs, the resulting run has higher and higher amperage running over it, with little to distinguish it from the runs it combined. I mean, you could increase the wire size each time you combined, but that would look sorta funky.

I would suggest best practices being not the use of inline combiners, but rather a combiner box on the roof:
https://www.amazon.com/ECO-WORTHY-Co.../dp/B07F5HDP2W

This way all of your runs into the box are the same, and the run out from the box is distinct. Its neat, organized, predictable. Each run is fused with a combined breaker for the output. Yes, you'll likely have some runs that are longer than if combined inline as a result based on your original post.

Will what you're suggesting work... yeah, given you pay close attention to cable ratings and combined amperage. Its just kind of messy in my opinion.

[Danjo]

Originally Posted by Michael_Grumbach

Hi Folks,
I'm connecting (4) pairs of series panels in parallel.
I was planning on connecting pair one to pair two with a 2 in 1 out cable combiner, then connecting that output to the third pair with another 2 in 1 out combiner, then connecting that output to the fourth pair with another combiner.
This will take less cable than if I ran all four pairs to a 4 in 1 out cable combiner, but I don't know if there is a reason to go with the single 4 in 1 out over the multiple 2 in 1 out combiners.
Any experienced folks out there with thoughts on the matter?

That’s what I did with 3 pairs of 2 strings. Works great as long as you stay within the cable’s rated ampacity.

That being said, I did it because that’s what Renogy provided. If they had given me a combiner box I would have done it that way.

[Rock-N-Ruth]

Originally Posted by Michael_Grumbach

Hi Folks,
I'm connecting (4) pairs of series panels in parallel.
I was planning on connecting pair one to pair two with a 2 in 1 out cable combiner, then connecting that output to the third pair with another 2 in 1 out combiner, then connecting that output to the fourth pair with another combiner.
This will take less cable than if I ran all four pairs to a 4 in 1 out cable combiner, but I don't know if there is a reason to go with the single 4 in 1 out over the multiple 2 in 1 out combiners.
Any experienced folks out there with thoughts on the matter?

We put 12 327W Sunpower panels on the roof. To get the best output, and we do, we connected them in groups of four parallel. Each group of 4 has its own run to it's own solar controller. I built my own combiner boxes with ground buss bars from the big box store, total cost per combiner, less than 20 bucks. So, three 20 dollar combiner boxes on the roof. Three runs of cable. We used #6 Copper TTFN. The longest run is about 45 Feet.
We used very inexpensive MakeskyBlue Solar controllers. (About $130.00/ea)

The end result:
In the morning around 10:00 after a night of running the Air conditioning, Oxygen concentrator, 2 Bi-Pap machines, Fridge and freezer, along with assorted phone chargers, fans, TV etc, while Hunny is using the Microwave, and the A/C is still on: The front panels are producing between 1250W and 1420W, the midship panels and rear panels are cranking out about the same.
This is as much as 4200W which is more than the panels are rated at.

By noon the front panels will be producing about 650W while the midship panels will be producing 300W and the rear panels only about 12W. This is because our massive 1320AH LifeP04 battery bank is topped off and reading 28.7V. Yes the Air Conditioning is still on. We run the Mini-Split 24/7 in the summer and often in the winter (heat mode).