400W Solar installed on 5th wheel, ready to upgrade

[corn18]

I finally got the 2x200W Rich solar panels installed on strut channel. All hooked up and working. I have another 2x200W Rich solar panels with 40A MPPT on the way. That will give me 800W and 2xMPPTx100V/40A. I decided to run 2 sets of 10ga wire from the roof, so each SCC will have its own wires to the roof.

I think I want to over panel both SCCs by adding a third panel to each circuit in series. So 3S x 2. Not really 3S/2P because I will be bringing down each 3S on the dedicated 10ga wires. That will give me 1200W of solar but I can only use about 1000W max due to the SCCs. I'm ok with that. I like the idea of over panelling because I will never tilt the panels.

My question is where should I put the third panel for each circuit? I can fit 12 panels on my roof. I am thinking adding them forward of the 4 I will have on the roof already. Appreciate your thoughts. Always helpful to get another set of eyes and idears.



Data of the 200W Rich solar panels:

 

[williamsk913]

I would put the third panel is the same area as the other panels they go with and seperate the two arrays a bit (my thought path is that if shade is on one area the other might still have good sun?).

 

[FilterGuy]

I finally got the 2x200W Rich solar panels installed on strut channel. All hooked up and working. I have another 2x200W Rich solar panels with 40A MPPT on the way. That will give me 800W and 2xMPPTx100V/40A. I decided to run 2 sets of 10ga wire from the roof, so each SCC will have its own wires to the roof.

I think I want to over panel both SCCs by adding a third panel to each circuit in series. So 3S x 2. Not really 3S/2P because I will be bringing down each 3S on the dedicated 10ga wires. That will give me 1200W of solar but I can only use about 1000W max due to the SCCs. I'm ok with that. I like the idea of over panelling because I will never tilt the panels.

My question is where should I put the third panel for each circuit? I can fit 12 panels on my roof. I am thinking adding them forward of the 4 I will have on the roof already. Appreciate your thoughts. Always helpful to get another set of eyes and idears.

View attachment 67770

Data of the 200W Rich solar panels:

View attachment 67772

My first reaction was that 3S would probably have too high of a Voc, but doing some quick math, it is good even in extreme cold.

Looking at the pictures, the two sets of 2S will always have a different angle to the sun so it is a really good thing you are putting them on separate controllers.

The different angles is also key for adding the 3rd panel. You don't want one of the panels to have a different angle to the sun than the others. Therefore, the 3rd panel should be in line with the first two. That kinda rules out the two positions in the center of the roof.

Since it is an RV, shading is a complete unknown. Each place you go will have a different situation. I started to say put the 3rd panel in-line but far away from the others to maximize the probability of one of them being in the sun.....but then I realized that it might be just as likely that having them all together might optimize the possibility of having all of them in the sun. So.... just for ease of installation, I would put them next to the existing two

 

[corn18]

My first reaction was that 3S would probably have too high of a Voc, but doing some quick math, it is good even in extreme cold.

Looking at the pictures, the two sets of 2S will always have a different angle to the sun so it is a really good thing you are putting them on separate controllers.

The different angles is also key for adding the 3rd panel. You don't want one of the panels to have a different angle to the sun than the others. Therefore, the 3rd panel should be in line with the first two. That kinda rules out the two positions in the center of the roof.

Since it is an RV, shading is a complete unknown. Each place you go will have a different situation. I started to say put the 3rd panel in-line but far away from the others to maximize the probability of one of them being in the sun.....but then I realized that it might be just as likely that having them all together might optimize the possibility of having all of them in the sun. So.... just for ease of installation, I would put them next to the existing two

View attachment 67776

The reason I was leaning towards adding them forward is because we back into sites 95% of the time and that's usually where all the trees are. If I keep the 3rd panel forward, it is less likely to get shaded.

I do like your thinking on keeping them on the same angle with the rest. Hadn't thought of that.

 

[FilterGuy]

The reason I was leaning towards adding them forward is because we back into sites 95% of the time and that's usually where all the trees are. If I keep the 3rd panel forward, it is less likely to get shaded.

That is as good of an argument as any.... in fact, maybe it would be better to put two in front and one in back.

 

[corn18]

That is as good of an argument as any.... in fact, maybe it would be better to put two in front and one in back.

Hmmm.... Maybe something like this?