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  • Different voltage panels

    Just a newbie here. I have 2 sets of panels. 4 100watt combined parallel and 2 45watt kits. Can they be connected at a junction box without loosing wattage from either set?

  • #2
    Originally posted by Kuhlk50 View Post
    Just a newbie here. I have 2 sets of panels. 4 100watt combined parallel and 2 45watt kits. Can they be connected at a junction box without loosing wattage from either set?
    If they all have the same Vmp, they can efficiently be connected in parallel. If not,
    what are the Vmp and Imp of each? Bruce Roe

    Comment


    • #3
      Originally posted by bcroe View Post
      If they all have the same Vmp, they can efficiently be connected in parallel. If not,
      what are the Vmp and Imp of each? Bruce Roe
      They are all 12 volt panels. My plan is to hook the 100 watt panels in parallel and the 2 45 watt kits in parallel and then run the 2 sets of wires to a junction box. Then go with 1 set of wires to the house. I guess my question is does the connection at the box make them all parallel or are they considered 2 individual sources of power?

      Comment


      • #4
        Originally posted by Kuhlk50 View Post
        They are all 12 volt panels. My plan is to hook the 100 watt panels in parallel and the 2 45 watt kits in parallel and then run the 2 sets of wires to a junction box. Then go with 1 set of wires to the house. I guess my question is does the connection at the box make them all parallel or are they considered 2 individual sources of power?
        Then they will all be in parallel. Hope your wiring is short & heavy, do estimate your losses. If excessive,
        you could put the 2 100Ws in series and the 2 45Ws in series, parallel those with an MPPT controller, to cut
        wire losses to 1/4. Bruce Roe

        Comment


        • #5
          Originally posted by bcroe View Post
          Then they will all be in parallel. Hope your wiring is short & heavy, do estimate your losses. If excessive,
          you could put the 2 100Ws in series and the 2 45Ws in series, parallel those with an MPPT controller, to cut
          wire losses to 1/4. Bruce Roe
          The 100 watt are 17.8 volts 5.62 amp. The 3 panel kits are 14.5 volt 1 amp. per panel. So no matter where these panels are connected to in the same system, they all act like the lowest panel. That's the part I'm having trouble understanding. LOL..............The rest of the plan...........

          I'm looking at 120'. The wire is going to be 10/3 cord. The white & black are going to be the positive and the green will be ground. So you suggest to hook 2 100Ws in series and hook that to the other 2 100Ws in parallel. That would be like having 3 panels connected but there's actually 4. Correct?

          I have a 500 W Grid Tie inverter. Its a 10.3 volt - 30 volt model. Will it work for the MPPT controller? If not, what brand or model do you recommend.

          I think I'll keep the 2 kits closer to the house and use them to charge a 4, 6 volt deep cycle battery bank unless you think I need them to help push the juice the distance. Thank You for your time and input. Its greatly appreciated.

          Comment


          • #6
            Originally posted by Kuhlk50 View Post
            The 100 watt are 17.8 volts 5.62 amp. The 3 panel kits are 14.5 volt 1 amp. per panel. So no matter where these panels are connected to in the same system, they all act like the lowest panel. That's the part I'm having trouble understanding. LOL..............The rest of the plan...........

            I'm looking at 120'. The wire is going to be 10/3 cord. The white & black are going to be the positive and the green will be ground. So you suggest to hook 2 100Ws in series and hook that to the other 2 100Ws in parallel. That would be like having 3 panels connected but there's actually 4. Correct?

            I have a 500 W Grid Tie inverter. Its a 10.3 volt - 30 volt model. Will it work for the MPPT controller? If not, what brand or model do you recommend.

            I think I'll keep the 2 kits closer to the house and use them to charge a 4, 6 volt deep cycle battery bank unless you think I need them to help push the juice the distance. Thank You for your time and input. Its greatly appreciated.
            Oh sorry, you have 4 panels at 100W. You still haven't stated the Vmp & Voc, but they should all be pretty close
            if they are all "12V battery" panels. So you could connect 2 like in series and get double voltage at the same
            current, put 3 series pairs in parallel.

            That sounds like a max around 12A. A 240' loop of 10 gauge will have around 1/4 ohm, which would lose about
            3V out of your 24V with an MPPT controller. More loss than you'd like, thats the way it is with lower voltage.
            However that wire isn't rated for sun exposure or water tight connections. Grid tie doesn't work on such a
            small scale. I'm not recommending specific equipment. Bruce Roe

            Comment


            • #7
              Originally posted by bcroe View Post
              Oh sorry, you have 4 panels at 100W. You still haven't stated the Vmp & Voc, but they should all be pretty close
              if they are all "12V battery" panels. So you could connect 2 like in series and get double voltage at the same
              current, put 3 series pairs in parallel.

              That sounds like a max around 12A. A 240' loop of 10 gauge will have around 1/4 ohm, which would lose about
              3V out of your 24V with an MPPT controller. More loss than you'd like, thats the way it is with lower voltage.
              However that wire isn't rated for sun exposure or water tight connections. Grid tie doesn't work on such a
              small scale. I'm not recommending specific equipment. Bruce Roe
              100 watt = 17.8 vmp or 22.4 voc 5.62A Imp
              45W Kit = 14.5 vmp or 23.5 voc 1A per 15 watt panels 3 panels per kit

              I'll run cord threw pvc pipe and bury it. So I wasted my money on the Grid Tie inverter?

              Comment


              • #8
                Originally posted by Kuhlk50 View Post
                100 watt = 17.8 vmp or 22.4 voc 5.62A Imp
                45W Kit = 14.5 vmp or 23.5 voc 1A per 15 watt panels 3 panels per kit

                I'll run cord threw pvc pipe and bury it. So I wasted my money on the Grid Tie inverter?
                You need to submit to the Po Co for a permit to legally use a grid tie inverter;
                I doubt they will approve your equipment. Probably the 45W panels will work
                well enough with the 100W, since they have a higher Voc. Bruce Roe

                Comment


                • #9
                  Hmm! Good to know! Thanks for your input.

                  Comment


                  • #10
                    Originally posted by Kuhlk50 View Post
                    ...

                    I have a 500 W Grid Tie inverter. Its a 10.3 volt - 30 volt model. Will it work for the MPPT controller? If not, what brand or model do you recommend.

                    .
                    That 500 watt inverter is not a legal Grid Tie type and will never be accepted by your POCO.

                    You can use your panels if you just want to charge a battery system. Then a good MPPT charge controller would be recommended but still hard to tell how you would use those 15watt HF panels.

                    Comment


                    • #11
                      Originally posted by SunEagle View Post
                      That 500 watt inverter is not a legal Grid Tie type and will never be accepted by your POCO.

                      You can use your panels if you just want to charge a battery system. Then a good MPPT charge controller would be recommended but still hard to tell how you would use those 15watt HF panels.
                      What type is a legal Grid Tie Inverter? What is the one I have really good for then? They shouldn't even be on the market.

                      Comment


                      • #12
                        Originally posted by Kuhlk50 View Post
                        What type is a legal Grid Tie Inverter? What is the one I have really good for then? They shouldn't even be on the market.
                        Any of those "grid tie" inverters that plug into a receptacle are not UL listed and are illegal to use in the US and other countries.

                        The reason they are on the market is that you can sell anything you want on the Internet especially if it is legal somewhere in the world but it is the buyers responsibility to know if they can legally use it or not.

                        A legal Grid Tie inverter would be a SunnyBoy or SMA, Enphase, Fronius, PV Powered, Outback, Xantrex, and other name brands. You can check out the Solar Town website for a listing.

                        These have been properly tested by UL and are usually approved by any POCO.

                        Comment


                        • #13
                          Originally posted by SunEagle View Post
                          Any of those "grid tie" inverters that plug into a receptacle are not UL listed and are illegal to use in the US and other countries.

                          The reason they are on the market is that you can sell anything you want on the Internet especially if it is legal somewhere in the world but it is the buyers responsibility to know if they can legally use it or not.

                          A legal Grid Tie inverter would be a SunnyBoy or SMA, Enphase, Fronius, PV Powered, Outback, Xantrex, and other name brands. You can check out the Solar Town website for a listing.

                          These have been properly tested by UL and are usually approved by any POCO.
                          Once again thanks for the info!!

                          Comment

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