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  • #16
    Can you share the inverter part number, or a link to a data sheet?
    CS6P-260P/SE3000 - http://tiny.cc/ed5ozx

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    • #17
      Yeah, the inverter is some generic thing from China. The customer ordered it and I'm installing it LOL. Location is Belize, Central America...grid electricity is $0.85bz/KWh ($0.425USD/KWh), so the customer (small business owner) is looking to decrease his electric bill as some other businesses in the area have done.

      The Blue writing on the spec page I wrote in, it is my best guess at a model number as that was what was labeled on the shipping carton.

      Scan_20150217 (1).jpg Scan_20150217 (2).jpg Scan_20150217 (3).jpg
      3680W - FLEXmax 80 - FX3048T - 8x L16P-AC 435Ah

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      • #18
        One more thing...on page 6 it says it's spec'd for 440V +/- 38V....but the 3ph connection at the factory here is 480V...my best assessment (based on the medieval spec sheet), is that it'll run at 480V without issue.
        3680W - FLEXmax 80 - FX3048T - 8x L16P-AC 435Ah

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        • #19
          miahallen,

          I don't think anyone was trying to mock you, but were rather going for a sense of humor. Issue is I really don't think anyone helped you out too much, nor really answered your question; anyone can boil a process down to bullet points and still not be helpful (sorry guys).

          to answer yourfirst question, 101 resources and guidelines I used to find on google... I'd start by researching 'basic solar string sizing' or 'solar electricity inverter installation' or some such conglomeration of words and then start fishing. I don't have much more here because I havn't done this in a while, and I dont' have those bookmarked anymore... I will also often through the phrase "PDF" after a search term to look for documents written on the subject, because these are often a bit more well put together than websites, and easier for me to read.

          As far as books go, the Photovoltaic Design and Installation Manual was a solid beginner book and moves towards intermediate skillsets fairly quickly. There's also "Photovoltaic Systems, 3rd Edition", which is a textbook often used here in the states that I thought was actually useful. again, took a person from beginner through intermediate skill-sets. Neither will replace practical experience, but that's the nature of the trades.

          SensiJ did hit on something quite critical - our code requirements up here are likely different than yours down there - make sure you understand yoru electrical code fairly well. It's all about safety.

          Then you brought up string sizing... This is one of the more nuanced areas of system designing. some folks like to go full bore and max out full voltage allowances, and others try to place final string voltage (after de-rates) in teh upper range of the mppt range. I lean towards the latter, but I'm still trying to learn some things, and I've got a few questions about this.

          General benefits of higher panel-count strings are things like material costs and voltage losses... it's kind of a crapshoot, in my experience, and rarely comes out to more than a few dollars worth of difference, but in a given situation, there might be an obvious gain to one method over the other.

          Here, stateside, you'd need an AC disconnect too...

          and my 3phase experience is limited, I'm not going to advise there.

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          • #20
            Originally posted by miahallen View Post
            At the risk of further humiliating myself...I just would like some input on this subject one more time. I was awarded the contract to install this 20KW 440V 3ph grid-tie inverter. Based on those spec, the previous advice still stands, correct? And, I'm not talking about all the silliness, I'm referring to the technical advice

            Each panel is a 60-cell 35V 250W configuration, the inverter is rated for DC input of 620V with max open circuit voltage of 850V. "Range of MPPT Voltage" is 200-820V. I'm planning to run either:
            • four 15 panel strings. DC power should be sitting at about 525V and up to 28.5A
            • three 20 panel strings. DC power should be sitting at about 700V and up to 21.5A

            Either option should be OK for running 8ga wiring to the inverter (about 200ft round trip) with under 1% loss.
            The inverter will then be wired into the warehouse 3ph mains at 440V AC. I'll have a disconnect on the DC side. The inverter will handle up to 850V open circuit voltage, rated DC voltage is 620V.
            I am running similar panels, 5 strings of 12 running a 500' loop of 6 gauge, losses under 1%.
            The problem with a lot more voltage, is the more common (600 VDC) fuses and switches
            won't be able to handle it. I'd try to keep worst case under 600V, a boundary for many items.
            Bruce Roe

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            • #21
              Originally posted by miahallen View Post
              At the risk of further humiliating myself...I just would like some input on this subject one more time. I was awarded the contract to install this 20KW 440V 3ph grid-tie inverter. Based on those spec, the previous advice still stands, correct? And, I'm not talking about all the silliness, I'm referring to the technical advice

              Each panel is a 60-cell 35V 250W configuration, the inverter is rated for DC input of 620V with max open circuit voltage of 850V. "Range of MPPT Voltage" is 200-820V. I'm planning to run either:
              • four 15 panel strings. DC power should be sitting at about 525V and up to 28.5A
              • three 20 panel strings. DC power should be sitting at about 700V and up to 21.5A

              Either option should be OK for running 8ga wiring to the inverter (about 200ft round trip) with under 1% loss.
              The inverter will then be wired into the warehouse 3ph mains at 440V AC. I'll have a disconnect on the DC side. The inverter will handle up to 850V open circuit voltage, rated DC voltage is 620V.
              Let me get this straight: You were awarded a contract for solar work of some sort. I'd suspect that means you are in an electrical or mechanical and/or solar type business ? And, you then come to a place with a lot of unvetted opinions asking what seems to be questions a professional ought to have learned the answers to long before getting into the business, or at least learned where to find answers before getting into the business. I'll not ask if you know what you're doing - that seems somewhat obvious to me. I'd ask if your client knows what you are doing, and also what your client might think if your inexperience and lack of basics was discovered.

              Comment


              • #22
                Originally posted by Rocksteady2R View Post
                miahallen,

                I don't think anyone was trying to mock you, but were rather going for a sense of humor. Issue is I really don't think anyone helped you out too much, nor really answered your question; anyone can boil a process down to bullet points and still not be helpful (sorry guys).

                to answer yourfirst question, 101 resources and guidelines I used to find on google... I'd start by researching 'basic solar string sizing' or 'solar electricity inverter installation' or some such conglomeration of words and then start fishing. I don't have much more here because I havn't done this in a while, and I dont' have those bookmarked anymore... I will also often through the phrase "PDF" after a search term to look for documents written on the subject, because these are often a bit more well put together than websites, and easier for me to read.

                As far as books go, the Photovoltaic Design and Installation Manual was a solid beginner book and moves towards intermediate skillsets fairly quickly. There's also "Photovoltaic Systems, 3rd Edition", which is a textbook often used here in the states that I thought was actually useful. again, took a person from beginner through intermediate skill-sets. Neither will replace practical experience, but that's the nature of the trades.

                SensiJ did hit on something quite critical - our code requirements up here are likely different than yours down there - make sure you understand yoru electrical code fairly well. It's all about safety.

                Then you brought up string sizing... This is one of the more nuanced areas of system designing. some folks like to go full bore and max out full voltage allowances, and others try to place final string voltage (after de-rates) in teh upper range of the mppt range. I lean towards the latter, but I'm still trying to learn some things, and I've got a few questions about this.

                General benefits of higher panel-count strings are things like material costs and voltage losses... it's kind of a crapshoot, in my experience, and rarely comes out to more than a few dollars worth of difference, but in a given situation, there might be an obvious gain to one method over the other.

                Here, stateside, you'd need an AC disconnect too...

                and my 3phase experience is limited, I'm not going to advise there.
                Thanks for all the tips RS

                Originally posted by bcroe View Post
                I am running similar panels, 5 strings of 12 running a 500' loop of 6 gauge, losses under 1%.
                The problem with a lot more voltage, is the more common (600 VDC) fuses and switches
                won't be able to handle it. I'd try to keep worst case under 600V, a boundary for many items.
                Bruce Roe
                I think I've come to the same conclusion, thanks Bruce

                Originally posted by J.P.M. View Post
                Let me get this straight: You were awarded a contract for solar work of some sort. I'd suspect that means you are in an electrical or mechanical and/or solar type business ? And, you then come to a place with a lot of unvetted opinions asking what seems to be questions a professional ought to have learned the answers to long before getting into the business, or at least learned where to find answers before getting into the business. I'll not ask if you know what you're doing - that seems somewhat obvious to me. I'd ask if your client knows what you are doing, and also what your client might think if your inexperience and lack of basics was discovered.
                I am a young entrepreneur, just getting my business going. I do not have much experience, and I sell myself to the clients as a novice. There are no electrical codes here in Belize, and based on most of the other electrical work I've seen done here, I'm confident in my ability to do better work. Not only that, but MY EGO IS NOT SO BIG THAT I'M SCARED TO ASK BASIC QUESTIONS...that alone separates me from most other options here in Belize. No, I don't know everything about how to do what I'm doing...that is why I am seeking advice & information to help me learn. My client knows that I'm a novice & that I've never worked with 3-ph before.
                3680W - FLEXmax 80 - FX3048T - 8x L16P-AC 435Ah

                Comment


                • #23
                  Well it looks like that just went unanswered . Despite what I know and what I think I know ,I realise that I may be wrong .
                  Any sensible person does it that way and I for one like to see someone else say "Yes I think that is OK too" or "Look I would do it this way..."

                  I guess after 18 months or so the job is done and the result known . Its a shame he didn't come back and complete his work here as I would have liked to know what his chosen course was and if it worked satisfactorily. (Or maybe it didn't and he is grave bound)

                  Wouldn't it be nice to be able to do it without all the Governmental crud.
                  Last edited by tytower; 11-20-2016, 03:51 AM.

                  Comment


                  • #24
                    Originally posted by tytower View Post
                    Well it looks like that just went unanswered .
                    I guess after 18 months or so the job is done and the result known . Its a shame he didn't come back and complete his work here as I would have liked to know what his chosen course was and if it worked satisfactorily. (Or maybe it didn't and he is grave bound)

                    Wouldn't it be nice to be able to do it without all the Governmental crud.
                    Well, standards can be a PITA when they get out of hand, and while designing and building stuff without some of the government crud has the advantage of likely improvement of the gene pool some when yahoos did themselves in via ignorance, which is probably a good thing for society in the long haul, I'm not sure, for example, I'd want to cross a long span bridge or live in a home constructed without the benefit of some building codes administered and enforced by some governmental authority.

                    If nothing else, such oversight might tend to provide society with some protection from some damage from the type of ignorance and inexperience such as exhibited by the OP.

                    Every home I've owned has had some prior genius DIY'er stuff that needed correction for what I considered to be safety reasons, usually, but not exclusively involving electrical in some way.

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