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Installation of 400 Watt solar kit (4 panels) 390CPMY

Posted: March 20th, 2021, 4:59 pm
by tonyiiiafl
I have my panels and controller. My 400 Watt system is 4 100W panels and a 40A MPPT controller. I am going to have to run 2 on one side of the aft hardtop and 2 on the other side with a space in between for expansion if needed. I have the plastic corner mounts that stick on with Silkaflex(?) as the panels are also glued to them with the same. NOW, I have read a LOT about how to do this.....Series? Parallel? I was going to hook each side up in series hence having 2 24V banks, then connecting together with the connectors to form the one lead to the controller. From what I gather, if one set is shaded the other will set will perform. Where would you put the controller? I was going to place it in the salon, then make the run to the house batteries to charge. I could always send power to house and start bank by selecting “Both” on the selector switch. Is that too far away from the panels? Also, I was thinking of a small disconnect switch at the run to the batteries in case I wanted to shut off the system. Thoughts? Experience?

Re: Installation of 400 Watt solar kit (4 panels) 390CPMY

Posted: March 20th, 2021, 6:25 pm
by Tireless
I have a 30 amp breaker between my panels and the controller. I also have an on/off switch on the positive line between the controller and the battery. Your panels will always produce power, so you want to be able to not only protect your controller, but be able to shut the power to the controller off if you have to.

I have 4 panels. They are separated 2 and 2 to ensure that the shadows don’t interfere with the charging.

I put my controller in my salon to shorten the run from the panels to the controller. I was told to keep it under 20 feet for the gauge of wire that came with the set up. I was then able to keep the wire going from the controller to the batteries under 14’.

Greg

Re: Installation of 400 Watt solar kit (4 panels) 390CPMY

Posted: March 20th, 2021, 8:20 pm
by tonyiiiafl
So you have the breaker to the controller and an on/off switch between controller and batteries. I like the redundancy. I would shut the system down the system when docked at the marina and the on board charger is running. I would also probably shut it off while underway when the alternators are doing their work. Do you have 2 panels wired in series (24V) then connected to the controller or do you have 2 panels connected in parallel (12V) and then to the controller? I have heard that 24V will produce better as long as you have the MPPT controller?

If I placed my controller in the Salon, I would have approx a 15’ run from panels to controller and 5’ to the 2 6V golf cart batteries wired in series to make 12V. Next year I would like to add another 2 6V batteries bank to supplement my house bank. Looking forward to your reply as to how you have the panels connected.

Re: Installation of 400 Watt solar kit (4 panels) 390CPMY

Posted: March 21st, 2021, 6:24 am
by Midnightsun
2 in series and 2 in parallel sounds just right IMHO. To fuse or not to fuse, well that depends. Definitely want it fused after the controller. I went into my 12v breaker panel from my controller into a new 50a breaker I installed in a vacant slot and labeled it "solar" and the negative from my controller to the negative bus bar. As for the fuse from the panels to the controller, see here. https://www.explorist.life/how-to-fuse- ... t-need-to/

Re: Installation of 400 Watt solar kit (4 panels) 390CPMY

Posted: March 21st, 2021, 8:30 am
by tonyiiiafl
As I thought. Thanks Hans!

Re: Installation of 400 Watt solar kit (4 panels) 390CPMY

Posted: March 21st, 2021, 11:27 am
by Tireless
I have them in series/parallel. Each panel is connected to a second with a “Y” connectors. Each pair of panels are then joined with “Y” connectors and then the positive and negative wire run to the controller.The breaker was installed between the breaker and the controller to provide protection for the controller and give the ability to stop the power from going to the controller if I choose. I also have a fuse at the battery and the switch is handy to have between the controller and the batteries .The entire hook up was based on the advice from my supplier.

I don’t turn the panels off during the season when there are other methods of charging taking place. The controller accounts for this and there is no issues. This is great if there is a power issue at the dock and your batteries will still be charged. The panels are always powered up any way.

Your distances sound like they are within spec.

Greg

Re: Installation of 400 Watt solar kit (4 panels) 390CPMY

Posted: March 21st, 2021, 3:11 pm
by tonyiiiafl
Here is a ROUGH drawing I did on my ipad as to how I am planning on connecting the panels. LOL, Like a 4 year old with a crayon!
Holodeck solar.jpg

Re: Installation of 400 Watt solar kit (4 panels) 390CPMY

Posted: March 21st, 2021, 6:32 pm
by tonyiiiafl
What Silkaflex would you all use to bond the corner brackets to the fiberglass aft hardtop and the panels to the bracket? 291 marine? 3M 5200 0r 4200?

Re: Installation of 400 Watt solar kit (4 panels) 390CPMY

Posted: March 21st, 2021, 7:02 pm
by Tireless
I was looking at the pictures of what I did and as my memory, serves me I believe your diagram is the way I wired my panels.

As for the product to use to hold down your brackets, I used 3M 4200 as opposed to 5200. 5200 is stronger, but if you ever want to remove them for what ever reason it would be more difficult. I was advised that 3M 4200 is sufficient for this application, however you should go with what makes you comfortable.

Greg

Re: Installation of 400 Watt solar kit (4 panels) 390CPMY

Posted: March 21st, 2021, 7:44 pm
by Viper
Ya go with 4200, 5200 is permanent. If you're not careful when removing something with 5200, it'll actually rip out gelcoat and glass.