3 Panel System on Sailboat, Need Help

montenido
montenido Registered Users Posts: 3
in Solar Beginners Corner #1
Hi everyone. Today I installed 3 BP175 panels (24v, Imp 4.9, Isc 5.4) on the arch of my sailboat. I have yet to buy the controller and wiring, so I wanted to run some questions by you. First, I want to have them in parallel, not in series. Can I use the fittings that in essence tap into the main line for each panel? I'm sorry. I'm not sure what they are called, but they allow a parallel run where my three panels would end up with a single pair of wires connecting to the combiner, which would be about 20' away. This would be easier for me as I would only have to make one water-proof hole in the deck of the boat for the wires. My second question hinges on the answers to the first one, and that is would I need a combiner if I only had one paired wire coming from the panels? Could I just run it to a single breaker, and then on to the controller?

For the controller I am pretty sure I can get by with a 45A MPPT controller, but that might not leave room for adding additional panels in the future. Would a 60A controller be overkill?

Thanks in advance, Bill
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Comments

  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #2
    Re: 3 Panel System on Sailboat, Need Help

    Welcome to the forum.

    Right now with three panels in parallel you should be using a combiner box with fuses/circuit breakers. This prevents one panel from being overloaded with current from the other two in the event the first should short out. It is a safety precaution; it will not affect function.

    If you're planning on future expansion, installing the combiner box and appropriate size wiring now will make that easier. It's nice to be able to just plug in more panels and flip their breakers to 'ON'.

    If this is a 12 Volt system then your three panels should produce around 34 Amps peak. This would not be 'too little' for a 60 Amp controller, and again if expansion is in the future you may as well prepare for it now.
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  • kellylipp
    kellylipp Registered Users Posts: 21 ✭✭
    #3
    Re: 3 Panel System on Sailboat, Need Help

    Here is a link to my blog where you find a number of installations on RVs. Similar to what your are trying to do. A single combiner box on the outside and one penetrating hole to the inside makes the most sense for you (as Cariboocoot stated).

    http://cuernoverdesolar.wordpress.com/
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