Announcement

Collapse
No announcement yet.

Help sizing charge controller

Collapse
X
  • Filter
  • Time
  • Show
Clear All
new posts

  • #16
    Originally posted by sensij View Post

    Assuming the controller you select has 150 V max input, put all three panels in series.

    .
    The only rating I see on controllers listed online is output, how do I tell if the controller I need will handle 150 V max input?

    Comment


    • #17
      Originally posted by cmutwiwa View Post

      Thanks Sensij, yes right now all loads are 12V, however this has been a limitation, I need to power a PC mostly during the day, so changing the lighting to accommodate the 24V system is an expense am willing to incur. I've read on other post here that its not a good idea to connect the panels in parallel since this will increase the current hence more cost in wiring and high power loss, so I think it will be better off doing it in series like you say.
      Hold the bus there my friend. What the heck do you think the wiring cost is going to be with 12 volts distribution? You will need to own stock with Freeport-MacMoRan. 12 volts is fine for RV's because the distances are so short. The other downside is 12 volt gizmos are expensive and usually very low quality.

      My company does a lot of lighting, and I mean a lot of lighting. The only advantage, and it is a stretch, low voltage fixtures can be smaller but comes with a premium price. Bottom line is low voltage cost more to install, but offers no operational savings. So look at the big picture. Do not let the trees blind you preventing you from seeing the forest.
      Last edited by Sunking; 01-11-2018, 05:21 PM.
      MSEE, PE

      Comment


      • #18
        Originally posted by cmutwiwa View Post

        The only rating I see on controllers listed online is output, how do I tell if the controller I need will handle 150 V max input?
        Spec sheet.

        MSEE, PE

        Comment


        • #19
          Originally posted by cmutwiwa View Post

          The only rating I see on controllers listed online is output, how do I tell if the controller I need will handle 150 V max input?
          You're going to have to post links to what you are looking at for more specific help. I'm not sure what vendors will reliably deliver to Kenya, or what the pricing will be, so it would probably be better for you to share what you are seeing in the budget you have in mind. The links will cause your post to be "unapproved" and go to moderation before it shows up, but the moderators will see it isn't spam and approve it.
          CS6P-260P/SE3000 - http://tiny.cc/ed5ozx

          Comment


          • #20
            Originally posted by sensij View Post

            You're going to have to post links to what you are looking at for more specific help. I'm not sure what vendors will reliably deliver to Kenya, or what the pricing will be, so it would probably be better for you to share what you are seeing in the budget you have in mind. The links will cause your post to be "unapproved" and go to moderation before it shows up, but the moderators will see it isn't spam and approve it.
            True, the only online place I can & I do shop reliably is eBay, and most of the items are always from China, there are the American controllers I see most of you recommend but they dont ship to Kenya and the few that does the shipping price is way beyond my budget. The only option I have is to try...see links below, your advice is most welcome...

            https://www.ebay.com/itm/MPPT-Solar-...2C9d4-eRcUqEuA

            https://www.ebay.com/itm/30A-40A-50A...lNtAQ0Z2xcIlKA

            Comment


            • #21
              Originally posted by Sunking View Post

              Hold the bus there my friend. What the heck do you think the wiring cost is going to be with 12 volts distribution? You will need to own stock with Freeport-MacMoRan. 12 volts is fine for RV's because the distances are so short. The other downside is 12 volt gizmos are expensive and usually very low quality.

              My company does a lot of lighting, and I mean a lot of lighting. The only advantage, and it is a stretch, low voltage fixtures can be smaller but comes with a premium price. Bottom line is low voltage cost more to install, but offers no operational savings. So look at the big picture. Do not let the trees blind you preventing you from seeing the forest.
              Yes I've thought of the same too Sunking, I've already made up my mind to go with a 24V system. Thank you so much for your sincere advice on this forum.

              Comment


              • #22
                Originally posted by cmutwiwa View Post

                True, the only online place I can & I do shop reliably is eBay, and most of the items are always from China, there are the American controllers I see most of you recommend but they dont ship to Kenya and the few that does the shipping price is way beyond my budget. The only option I have is to try...see links below, your advice is most welcome...

                https://www.ebay.com/itm/MPPT-Solar-...2C9d4-eRcUqEuA

                https://www.ebay.com/itm/30A-40A-50A...lNtAQ0Z2xcIlKA
                Ok, the controllers in the first link accept up to 130 V for the 20-40 A sizes, and 150 V for the 50 and 60 A size.

                The controllers in the 2nd link accept up to 105 V when used in a 24 V system. (specs here).

                To use your panels in a 24 V system, you *must* put them in series, a single panel won't produce enough voltage.

                With three panels, you are looking at 38.6 * 3 = 115.8 Voc, at 25 deg C. I think it stays warm enough there that the 130 V limit would be OK if you go with the 30 or 40 A controller. The 150 V limit of the 50A and 60 A controllers is definitely ok.

                The 105 V limit of the 2nd link disqualifies it from consideration.
                CS6P-260P/SE3000 - http://tiny.cc/ed5ozx

                Comment


                • #23
                  Originally posted by sensij View Post

                  Ok, the controllers in the first link accept up to 130 V for the 20-40 A sizes, and 150 V for the 50 and 60 A size.

                  The controllers in the 2nd link accept up to 105 V when used in a 24 V system. (specs here).

                  To use your panels in a 24 V system, you *must* put them in series, a single panel won't produce enough voltage.

                  With three panels, you are looking at 38.6 * 3 = 115.8 Voc, at 25 deg C. I think it stays warm enough there that the 130 V limit would be OK if you go with the 30 or 40 A controller. The 150 V limit of the 50A and 60 A controllers is definitely ok.

                  The 105 V limit of the 2nd link disqualifies it from consideration.
                  Thank alot sensij for the helpful info.
                  I will try the controller in the first link.

                  Comment

                  Working...
                  X