Looking for wiring tips

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  • LeeLewis
    Member
    • Feb 2018
    • 88

    #16
    I've updated the diagram. Maybe this isn't that complicated now.
    I can buy a large outdoor box to house combiners, inverters, etc, then use AC wiring to get into the house from the canopy.
    I mainly have to figure out what amperage I'm looking at per string since my calculation was obviously wrong.

    Comment

    • DanS26
      Solar Fanatic
      • Dec 2011
      • 974

      #17
      The Daisy Chain and the Leapfrog method are both "series" wiring methods. Your new diagram is not clear on which series method you will use. The combiner box creates the parallel for the three arrays.

      Comment

      • LeeLewis
        Member
        • Feb 2018
        • 88

        #18
        I don't want to use series, I want three panel parallel strings to the combiner so that shading is less of an issue. You're right, I did it again LOL. I'm not very good with this diagram problem so I keep losing track of what I'm doing as I fight with it. Here is another version, this time, showing only one string of three panels wired in parallel to the combiner. Imagine of course, additional strings to the combiner. I upgraded the combiner to six inputs.

        At this point, I'm thinking of the setup in this way.
        Panels to combiner. Combiner to inverter. AC output to the house where I'd use the AC to charge batteries rather than the usual way such as using an inverter/device that would charge/maintain the batteries etc.

        solar-parallel.png
        Last edited by LeeLewis; 06-25-2023, 11:09 AM.

        Comment

        • SunEagle
          Super Moderator
          • Oct 2012
          • 15124

          #19
          Originally posted by LeeLewis
          I don't want to use series, I want three panel parallel strings to the combiner so that shading is less of an issue. You're right, I did it again LOL. I'm not very good with this diagram problem so I keep losing track of what I'm doing as I fight with it. Here is another version, this time, showing only one string of three panels wired in parallel to the combiner. Imagine of course, additional strings to the combiner. I upgraded the combiner to six inputs.

          At this point, I'm thinking of the setup in this way.
          Panels to combiner. Combiner to inverter. AC output to the house where I'd use the AC to charge batteries rather than the usual way such as using an inverter/device that would charge/maintain the batteries etc.

          solar-parallel.png
          I understand your desire to not lose power due to shading but I also thought you wanted to save money by not having a large wire between the combiner and inverter. Wiring the panels in parallel increases the amount of amps and the wire size.

          Comment

          • LeeLewis
            Member
            • Feb 2018
            • 88

            #20
            Yes, I understand that and asked about it in another comment. There is no data to show what the output is of the panels so really just kind of guessing that it's between 7 to 9amps.
            If 7, I could put only 2 panels per string since the fuses are only 15 amps per input but that's pushing the fuse a little. That said, I don't know what the chances are of ever hitting that maximum amperage output anyhow. If I did three panel strings, it would blow the fuse IF it ever actually got to 15 amps. So maybe it's a trial and error thing. Worse comes to worse, I have to get a higher rated combiner to handle three panels.

            This is all based on the input I've received so far and my understanding of how this has to work.

            Comment

            • DanS26
              Solar Fanatic
              • Dec 2011
              • 974

              #21
              Post the inverter and specs that you plan to use with this setup.

              Comment

              • SunEagle
                Super Moderator
                • Oct 2012
                • 15124

                #22
                Originally posted by LeeLewis
                Yes, I understand that and asked about it in another comment. There is no data to show what the output is of the panels so really just kind of guessing that it's between 7 to 9amps.
                If 7, I could put only 2 panels per string since the fuses are only 15 amps per input but that's pushing the fuse a little. That said, I don't know what the chances are of ever hitting that maximum amperage output anyhow. If I did three panel strings, it would blow the fuse IF it ever actually got to 15 amps. So maybe it's a trial and error thing. Worse comes to worse, I have to get a higher rated combiner to handle three panels.

                This is all based on the input I've received so far and my understanding of how this has to work.
                Well the panel manufacturer is required to post the Imp and Vmp on the back of each panel. That information should help you determine the amount of voltage and current the panels can generate under the best conditions.

                Comment

                • LeeLewis
                  Member
                  • Feb 2018
                  • 88

                  #23
                  I posted that in another comment but here it is again; https://www.amazon.com/dp/B09BTX2YQ5

                  I also shared the panel details in another comment but the data sheet is with the microinverter installed so they don't talk about the panel specifically other than with AC output.
                  I'm making guestimates based on some info about the panel which should be pretty standard and the input of the inverter to get some idea of the panel.
                  I'll post that info again which is from the data sheet;

                  Mage / Powetec Plus, 250 / 6 PL US AC.
                  AC output, 240V
                  AC Max Cont output current, 0.992A
                  AC Max Cont output power, 238W

                  The inverters are Pantheon II.
                  INPUT (DC) DATA P250LV-208/240
                  Recommended STC Module Input Power Rating 235 W – 280 W
                  Maximum Continuous Input Power 250 W
                  Maximum Input Voltage 48V
                  MPPT Voltage Range 18V-37V
                  Maximum Power Voltage Range 25V-37V
                  Maximum DC Short Circuit Current 15A
                  Maximum Input Current 10A

                  Comment

                  • DanS26
                    Solar Fanatic
                    • Dec 2011
                    • 974

                    #24
                    In post #5 you said you will not be using microinverters and your diagrams show strings. Now you're going back to micros........? Sorry, I don't think I can help you any more. Good luck.

                    Comment

                    • SunEagle
                      Super Moderator
                      • Oct 2012
                      • 15124

                      #25
                      Originally posted by LeeLewis
                      I posted that in another comment but here it is again; https://www.amazon.com/dp/B09BTX2YQ5

                      I also shared the panel details in another comment but the data sheet is with the microinverter installed so they don't talk about the panel specifically other than with AC output.
                      I'm making guestimates based on some info about the panel which should be pretty standard and the input of the inverter to get some idea of the panel.
                      I'll post that info again which is from the data sheet;

                      Mage / Powetec Plus, 250 / 6 PL US AC.
                      AC output, 240V
                      AC Max Cont output current, 0.992A
                      AC Max Cont output power, 238W

                      The inverters are Pantheon II.
                      INPUT (DC) DATA P250LV-208/240
                      Recommended STC Module Input Power Rating 235 W – 280 W
                      Maximum Continuous Input Power 250 W
                      Maximum Input Voltage 48V
                      MPPT Voltage Range 18V-37V
                      Maximum Power Voltage Range 25V-37V
                      Maximum DC Short Circuit Current 15A
                      Maximum Input Current 10A
                      That is the inverter data. Not the panel DC data.

                      You should also have the panel data which is usually on a nameplate on the back of the panel. It should provide you with a Wattage, Imp, Vmp, Voc and short circuit amp rating. But it is possible that when you wire an individual inverter to each panel they might not give you the panel DC rating.

                      Without the DC data for each panel you might have to guess both the Vmp and Imp amounts to wire them the way you want to going to a single inverter.

                      Comment

                      • LeeLewis
                        Member
                        • Feb 2018
                        • 88

                        #26
                        Originally posted by DanS26
                        In post #5 you said you will not be using microinverters and your diagrams show strings. Now you're going back to micros........? Sorry, I don't think I can help you any more. Good luck.
                        Uh? I am removing the inverters to convert some of the grid tied system to a DC setup. I'm not sure where you got that. Maybe I mentioned the possibility of using non grid tied converters but I don't remember posting that, it was just a thought.

                        Yes, I looked at the panels closely, there's nothing on them that gives any information on output.
                        Since the inverters accept 18-37 up to a max of 48VDC, and the panels on average are putting out 32VDC, this tells me my panels are max 48VDC.
                        I need to get up there again to get some averages on amperage.

                        Even in the power manager, there's no actual information about current but I can use the info shown I suppose to figure that out.

                        solar-output.png
                        Last edited by LeeLewis; 06-26-2023, 11:43 AM.

                        Comment

                        • SunEagle
                          Super Moderator
                          • Oct 2012
                          • 15124

                          #27
                          Originally posted by LeeLewis

                          Uh? I am removing the inverters to convert some of the grid tied system to a DC setup. I'm not sure where you got that. Maybe I mentioned the possibility of using non grid tied converters but I don't remember posting that, it was just a thought.

                          Yes, I looked at the panels closely, there's nothing on them that gives any information on output.
                          Since the inverters accept 18-37 up to a max of 48VDC, and the panels on average are putting out 32VDC, this tells me my panels are max 48VDC. Checking the output, I saw around 32VDC on average. I to get up there again to get some averages on amperage.

                          Even in the power manager, there's no actual information about current but I can use the info shown I suppose to figure that out.
                          Without the panel information (which it seems you have not been given) you would be guessing the open voltage that each panel can generate. That may not be an issue but you could exceed teh max DCV that the inverter can accept.

                          The rest (Vmp & Imp) can be gotten through testing but I now understand that changing a solar system that uses micros to a string is not always easy. I would say that the panels can generate 32VDC as close to the Vmp rating. And unless there is some type of markings showing the panel wattage it will be hard to calculate the Imp for each panel which affects the wire size and voltage drop calculation.

                          Comment

                          • LeeLewis
                            Member
                            • Feb 2018
                            • 88

                            #28
                            Correct and that's been the problem, not being able to get enough information and doing a lot of guessing.
                            I have this spec sheet on the panel but as mentioned, it includes the micro-inverter as part of the specs. Still useful, showing the panels max continuous output is 238W.
                            By knowing the max inputs of the micro-inverters, that could help me to get to a starting point of testing.

                            I could start by wiring three panels in series, connecting that string to one of the combiner inputs.
                            At worse, I'll blow a fuse during testing but I could monitor the output long before getting to an inverter. I've not purchased an inverter yet so my options are open.

                            panels-250_6_PL-US-AC-208-240-Datasheet_Rev1.pdf

                            Comment

                            • SunEagle
                              Super Moderator
                              • Oct 2012
                              • 15124

                              #29
                              Well if the pane is rated 238W and the Vmp is around 32V then the output amps for each panel is around 7 to 8. (238W / 32V = 7.43 amps). So maybe a guess of 8 amps and 32 volts is a starting place.

                              Comment

                              • LeeLewis
                                Member
                                • Feb 2018
                                • 88

                                #30
                                I initially thought each panel might be putting out under one amp so it looks like I have to seek out a new combiner since the inputs are only 15 amps.
                                I wondered how installers might deal with that. I guess a two panel string.

                                Comment

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