Hello. I have the AC200L. I have 6-200 watt panels to be mounted on my trailer roof. Each panel: Voc=22.5V, Isc=12.21A. My question is whether it would be better to connect all 6 panels in series (1200W, 135V, 12.21A) or do a combination 3S2P where I wire two groups of 3 panels in series and then connect them in parallel to input into the AC200L (1200W, 67.5V, 24.42A). My thoughts are that the 3S2P configuration would still provide input from at least 3 panels if one of the panels were shaded. Since the AC200L limits out at 15A input, I realize that I would have some input loss, but not sure of overall effect.
So, my question is which configuration would likely provide the best input? Does anyone have any experience with a similar configuration?
Offhand, go with the higher voltage lower amps (which means you can use thinner wiring to save money.)
The shade factor does present a bit of a problem. If the shading is expected to be only temporary then I wouldn’t worry about it, otherwise it’s going to suck losing power. When Winter came last year I had to move some panels around because they were falling into the shade of the house.
Hello BEv, and welcome to the forum! Short answer: 6 in series.
Your calculations are correct
In series, you reach indeed 135Voc in series and that is 10V below the unit’s max solar input voltage.
Cold temperatures slightly increase the voltage of panels, so keeping about 10% of satefy margin is a good practice.
With this in mind, your question of 6S vs 3S2P boils down to how much current AC200L can pull from panels:
AC200L can pull up to 15Amps from the panels.
If there’s more, it will simply not be used.
6S: your effective max power is 1200W.
3S2P: your effective max power is about 740W*
(* 15A of max power draw / 24.42A of available current = pulling only 61% of available power)
Parallelism also involves the need for thicker wires due to increased current (and increased resistive effect from the wires) and possible hotspots degrading your panels.
Thank you! Any shading should be temporary and I do have some portable panels and a generator as backup, if needed. And, saving money on wiring is always a good thing!
Thank you! The loss due to the max 15A current limit is significant in this case, so it definitely sounds like 6 in series is the best option. Thanks for a detailed explanation. Much appreciated!
Hello,
Derceto has told you all you need to know! One last piece of advice: if you park your trailer, make sure you don’t have one part of your panels in the shade and the others in full sun, otherwise your solar production will drop (the panels in the shade will limit the current intensity) and you may also get “hot spots” on your panels in the shade.
I had to daisy chain my 4 195 solar panels as the AC 200P wants high voltage and 12 amps max input.
It works great when we are driving to have the Refrigerator and the A/C running at the same time, when we arrive at the campground it’s cool inside and out food is chilled. The bonus is Ice for beverages.
