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Good AWG Sizes on MAIN POWER Distribution?

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  • Good AWG Sizes on MAIN POWER Distribution?

    I will never be running the stereo loud while running the inverter and will keep power consumption at a minimal. WIRE GAUGES.jpg


    And does it look right? It's a pretty simple drawing
    Last edited by inetdog; 10-20-2016, 12:04 PM. Reason: Spelling in title

  • #2
    What we have here is an Abortion that went very wrong.

    For starters wire size is determined by the breaker size and what the equipment requirements are. For example if you really have a 750 amp fuse would mean you would need a pair of 750 MCM cable about the size of your arm weighing some 12 pounds per linear feet. You woul dhave to own a copper mine and be rich to do what you have drawn. It would burn down the house eventually. Asid from that no consumer or DIY could even terminate a 4/0 correctly let along a cable 4 times it size.

    Secondly there is no solar application that would require 750 amps. That tells us you are operating at way to low of a voltage and stuck inside a damn 12 volt toy box. 100 amps max with 4 AWG is all that should be required. With 100 amp restriction means Panel Wattage and Inverter wattage should not exceed:

    1000 watts @ 12 volts
    2000 watts @ 24 volts
    4000 watts @ 48 volts
    8000 watts @ 96 volts

    What you have drawn is a ticking time BOMB. Why on earth do you show a 4/0 to earth? You do know that conductor does nothing right? It never carries any load current.

    Bottom line what the majorly wrong is I know you intend to run at 12 volts. There is no way safely possible to do this. No 6-volt battery even paralleled can deliver the amount of current you are looking at for any meaningful time and would be extremely dangerous. Even 100 amps can vaporize a battery terminal or connection. I assume you are looking at golf cart batteries 6 volt 220 AH. In parallel 12 volts at 440 AH. Those batteries are good up to a C/5 discharge rate or 440/5 = 88 amps, the limit on a 12 volt system.

    OK having said that, I can make this work, but you have to give a little. Let me know. For one give up the 2 Kwh Inverter and think more like 500 to 1000 watts. Ball is in your court. I will not help you do something dangerous and foolish.
    Last edited by Sunking; 10-18-2016, 07:32 PM.
    MSEE, PE

    Comment


    • #3
      OK now it is time to show you the mistakes. I redrew your sketch to make easier to follow, and to make it easy to spot what is wrong. You have 2 Critical errors and one major issue.

      Critical

      1. You have no circuit breaker or fuse shown between the batter term post and the +Buss Bar. You need a OCPD that physically gets installed on the battery Term Post.
      2/ You show no fuse going to the DC Distribution Block. I should not have to explain what is wrong with that. This compounds the missing fuse on the battery Term Post You would no protectio until after you do through the DC Distribution Block. Extremely dangerous.

      Major.

      1. You second Buss Bar feeding the Stereos has no purpose.



      OK now lets take a look at the other drawing. Makes it real easy to see what the problem is. Everything is protected. Although not labeled all fuses are 100 amps, and no wire larger than 4 AWG required unless you have a long run greater than 10-feet.

      But here is the kicker. The fuse between the battery and buss bar limits you to 100 amps. You really do not want more than 100 amps from your batteries, they cannot handle much more. What does this mean? It means you WILL NOT be running a microwave, stereo cranked up and all the lights on at the same time.

      Did you catch that? "all at the same time". Very easy to work around that.
      Last edited by Sunking; 10-18-2016, 11:08 PM.
      MSEE, PE

      Comment


      • #4
        Originally posted by Sunking View Post
        What we have here is an Abortion that went very wrong.

        For starters wire size is determined by the breaker size and what the equipment requirements are. For example if you really have a 750 amp fuse would mean you would need a pair of 750 MCM cable about the size of your arm weighing some 12 pounds per linear feet. You woul dhave to own a copper mine and be rich to do what you have drawn. It would burn down the house eventually. Asid from that no consumer or DIY could even terminate a 4/0 correctly let along a cable 4 times it size.

        Secondly there is no solar application that would require 750 amps. That tells us you are operating at way to low of a voltage and stuck inside a damn 12 volt toy box. 100 amps max with 4 AWG is all that should be required. With 100 amp restriction means Panel Wattage and Inverter wattage should not exceed:

        1000 watts @ 12 volts
        2000 watts @ 24 volts
        4000 watts @ 48 volts
        8000 watts @ 96 volts

        What you have drawn is a ticking time BOMB. Why on earth do you show a 4/0 to earth? You do know that conductor does nothing right? It never carries any load current.

        Bottom line what the majorly wrong is I know you intend to run at 12 volts. There is no way safely possible to do this. No 6-volt battery even paralleled can deliver the amount of current you are looking at for any meaningful time and would be extremely dangerous. Even 100 amps can vaporize a battery terminal or connection. I assume you are looking at golf cart batteries 6 volt 220 AH. In parallel 12 volts at 440 AH. Those batteries are good up to a C/5 discharge rate or 440/5 = 88 amps, the limit on a 12 volt system.

        OK having said that, I can make this work, but you have to give a little. Let me know. For one give up the 2 Kwh Inverter and think more like 500 to 1000 watts. Ball is in your court. I will not help you do something dangerous and foolish.
        Maybe I should have been more specific that I will only be using any appliances like a microwave when hooked up to shore power. The only real thing that the batteries will power is a small very energy efficient fridge, some LED lights, and the stereo once in a while. The only reason why I got the bigger inverter was because of the start up amps on the fridge I never really have any need to over 1000 watts. I could not get an answer from calling the manufacturer of the fridge what its initial start up amps were so I just got a bigger inverter to make sure. I was also going to buy a 2000 watt gen for away from shore power.

        Thanks for the information... I kind of realized the limitations early on in this venture a year ago.

        As for solar it's only 400 watts

        Comment


        • Sunking
          Sunking commented
          Editing a comment
          As long as you understand the limitations. To make sure you do not forget and a Fail Safe be sure to install a 100 amp fuse on the battery term post feeding the distribution. If you forget, it will remind you when you go over the limit, by turning everything off getting your attention real quick.

          Keep one thing in mind about me, I can be hard on folks to do it right or get lost. I have no problem hurting peoples feelings, it needs to be done at times as that is what truth is all about. But any regular and mods will tell you I care about your safety and money more than you do. If I make a recommendation it is sound, safe, and most cost effective to meet your requirements. I will use a 2 x 4 to get your attention and Attitude Adjustments.

          Its the military in me.
          Last edited by Sunking; 10-19-2016, 02:11 PM.

        • austexdude469
          austexdude469 commented
          Editing a comment
          LOL NP why do you think I asked you? 1. I knew you know wtf you are talking about. 2 I don't like people who fart around, I want straight truth.

          My skin is as thick as Rhino hide in rutting season...

      • #5
        OK, so this is in an RV or mobile install ? Most of the quality 1Kw pure sine inverters can manage the surge of starting a fridge. Going larger than you need, reduces battery runtime because of the increased overhead losses in the larger inverter.
        Sunking's example is a better way to wire than your sketch.
        Powerfab top of pole PV mount (2) | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
        || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
        || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

        solar: http://tinyurl.com/LMR-Solar
        gen: http://tinyurl.com/LMR-Lister

        Comment


        • #6
          Originally posted by Mike90250 View Post
          OK, so this is in an RV or mobile install ? Most of the quality 1Kw pure sine inverters can manage the surge of starting a fridge. Going larger than you need, reduces battery runtime because of the increased overhead losses in the larger inverter.
          Sunking's example is a better way to wire than your sketch.
          Yes it's a 1989 GMC conversion van I built from junk. I built the engine` from a bored block a couple years ago has about 15K on the motor. I am going on a trip all around the country take about a year... This is a long term goal I started in 2007 when I bought it.

          Good thing is, trip will take about as long as battery warranty. I will get cheap duracell GC batteries for my first go round with solar and after I learn every aspect there is to learn I will move on to more expensive batteries once I know what I'm doing better.

          Comment


          • #7
            Get a temperature correcting hydrometer and learn how to use it. You need one before a volt meter. A hydrometer tells you what state of charge the battery is. Voltage does not tell you much of anything. Best $10 investment you will ever make.
            Last edited by Sunking; 10-20-2016, 12:01 PM.
            MSEE, PE

            Comment


            • #8
              Originally posted by Sunking View Post
              Get a temperature correcting hydrometer and learn how to use it. You need one before a volt meter. A hydrometer tells you what state of charge the battery is. Voltage does not tell you much of anything. Best $10 investment you will ever make.
              OK thanks... been dealing with a head cold from hell. Either the stomach virus I had 5 days ago turned into a head cold or I caught a completely different bug. I am usually healthy but this is kicking my butt.

              Comment


              • Sunking
                Sunking commented
                Editing a comment
                Hope you get to feeling better.

              • austexdude469
                austexdude469 commented
                Editing a comment
                Thanks... starting to
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