Grid Tie question, sort of.

Discussion in 'Off Grid Living' started by CodE BluE, Oct 13, 2018.


  1. CodE BluE

    CodE BluE In need of resuscitation.

    Hi all, I want to know if I could pull my fuses from the main breaker box, then connect them to a plug end(fuse in line), to plug into my inverter. I'm hoping to be able to bypass the main breaker box and not need a transfer switch. Anyone with electrical experience or knowledge with grid tie systems, I really would like to hear your thoughts on this. Thanks.
     
  2. oil pan 4

    oil pan 4 Monkey+++

    Where is this at?
    I'm thinking it's not a good idea.
    You never want to by pass the buss bar over current protection.
    To do so would allow for a line side fault to occur on what ever extension cord you have tied in. It would be really bad.
     
    Merkun and sec_monkey like this.
  3. Dunerunner

    Dunerunner Brewery Monkey Moderator

    Very dangerous if you are back feeding the grid. You are on the house side of the meter if your Main breaker is closed. You will be energizing the utility lines with your inverter output, as long as it lasts. This could electrocute a utility worker who thinks that, since he has pulled the fuses on the line or transformer he is working on, that there is no electrical potential there. But, your inverter is feeding the line or transformer from the un-fused opposite direction.

    This should be done right and if you do not have the background to perform electrical work properly then you need to hire an electrical contractor. You not only risk an electrical fire, destruction of any grid tie equipment you have, but a fire that would take your home and possibly the lives of you and your family.
     
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  4. CodE BluE

    CodE BluE In need of resuscitation.

    Hi, I won't be tied into the grid at all. I'm talking about using the existing wiring to plug into the inverter. The main breaker would be off and the fuses pulled from the box.
     
  5. oil pan 4

    oil pan 4 Monkey+++

    So you are talking about using a stand alone inverter with out grid connection?

    If that is the case it's still not a good idea as most inverters use a floating neutral.

    You would need an actual 120/240v neutral ground bonded inverter to do this properly.
     
    sec_monkey likes this.
  6. Dunerunner

    Dunerunner Brewery Monkey Moderator

    So, it is not a grid tie system. It sounds like you are wanting to run just a few circuits in your home from your, I assume; solar/battery system. To do that, I would split those circuits deemed "Critical" out of your main panel, in other words create a Sub Panel that you can isolate with a breaker in your Main. Let's say you divide out 50 Amps of circuits. Those circuits powered from that distribution panel (Sub Panel) could then be isolated by feeding the inverter with the 50A feed from the Main. The inverter selects the commercial source when it is available and when it is not, it draws from your batteries to feed the sub panel. The inverter Isolates the Main from the Sub panel. You may need to find and inverter that will do this type of switching.
     
    sec_monkey likes this.
  7. CodE BluE

    CodE BluE In need of resuscitation.

    Thanks for the responses, I will continue with the research.
     
    Dunerunner likes this.
  8. Out in the woods

    Out in the woods off-grid in-the-forest beekeeper

    yes, that is very common in my area.

    People with generators will often do that.
     
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  9. BTPost

    BTPost Stumpy Old Fart,Deadman Walking, Snow Monkey Moderator

    If you do this, and something Happens, your Homeowners Insurance, will NOT pay off... By doing this you violated the NEC (National Electrical Code) which if you read your Insurance Policy (Fine Print) cancels the Policy. You would be better off to see if the OEM of your Main Panel, has a Linked Main Breaker Transfer Kit, for your Main Panel, which effectively does the same function, but complies with the NEC....
     
  10. CodE BluE

    CodE BluE In need of resuscitation.

    Thanks. I will check on the kit mentioned.
     
  11. Tevin

    Tevin Monkey+++

    Your idea will technically work, but it's extremely dangerous and is not even close to being NECA or NFPA compliant, or compliant with even the loosest safety standards. If anyone gets injured or your house burns down, I hope you have a good lawyer and a fat wallet because no insurance carrier will touch this.

    Anyone with "electrical experience or knowledge" will tell you to get a correct grid tie system or transfer switch.

    In my own house I fed my inverter into a separate breaker panel, then installed designated outlets around the house wired back to the second panel. It is a totally isolated/stand alone system that is not in any way physically connected to the commercial service. I do have a proper transfer switch off my main breaker panel for a generator so it will power everything in the house through the standard wiring.

    Also, not all inverters are certified to be wired to a breaker panel (in fact, very few are). I don't know why; I think it has something to do with grounding. If your inverter is not specifically designed for this type of service, then you are drifting into a grey area of safety.

    Good luck.
     
  12. TnAndy

    TnAndy Senior Member Founding Member

  13. If you open all breakers then pull your meter you will be disconnected from the grid. When/if you reconnect to the grid, make sure you have no load active again, ie: open all branch breakers then open main. Install meter , close main, close branch breakers one at a time. .Power company won't like missing seal.
     
  14. Dunerunner

    Dunerunner Brewery Monkey Moderator

    There should not be any necessity to pull the meter head. All distribution breaker panels have a Main Breaker. Just open that. The power company will hit you for a $150 reconnection fee to replace the locked ring on the meter.
     
    sec_monkey likes this.
  15. CodE BluE

    CodE BluE In need of resuscitation.

    I hear you, but I think you just wrote you are doing what I'm trying to do, with a couple differences. This is not a grid tie situation. Utility power would basically dead end at the meter. I have a second breaker box that matches the main. I shut off the main breaker, pull the wires, then insert them in the second breaker box. The main thought was to not have to run new wiring. I'm not talking about a 5kW or 20kW system, 127kW Gas Electric Inline Loop Power Supply. It has its own backup power, and with a 72 battery bank, at 1000mca each or 135aH, it should have plenty of storage. 12 Volt system ran in parallel. Getting this right is extremely important, so I really appreciate your thoughts and concerns.
    As far as the power coming in from the utility company, it would be a 2ND backup.

    Thanks.
     
    Last edited by a moderator: Oct 13, 2018
  16. techsar

    techsar Monkey+++

    Ummm...you're planning on running 72 batteries in parallel in a 12 volt system? And feeding a 127kw AC system with it?

    If so, you do realize you are talking about roughly 12000 amps of dc current...at 12 volts.

    Please tell me I am reading you incorrectly!
     
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  17. Dunerunner

    Dunerunner Brewery Monkey Moderator

    :cautious: I don't think you have really thought this system through, completely @CodE BluE ... The batteries you have selected appear to be for engine starting (Short Cycle) and not deep cycle batteries. Cranking batteries are designed to deliver high amperage for a short duration and like to be immediately recharged immediately following. Their duty cycle does not make them fit for power generation. I hope you haven't purchased any of this equipment yet...
     
    sec_monkey likes this.
  18. ghrit

    ghrit Bad company Administrator Founding Member

    That is for certain. They can, and will, assume you have jumpered the meter contacts and stole power.

    Correct, assuming the installation was done per code, which it may have been. Fuses are mentioned, which leads me to belive that this is a VERY old install with main fuses rather than a main disconnect breaker. From the various back and forth, I get the impression it is a kluge or left over from (say) the 40s or earlier. Start with the idea that if you are going to mess with the system in the tiniest manner, you will need to bring the whole ball of wax up to code.
    @CodE BluE , there is a lot more to be done to make your intent clear, so far we can't visualize the system.
     
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  19. oil pan 4

    oil pan 4 Monkey+++

    I'm just going to yank the meter.

    But I have a 120/240 generator with un-bonded neutral ground specifically setup for house tie in.
     
  20. DarkLight

    DarkLight Live Long and Prosper - On Hiatus

    Oh my dear sweet baby Jesus!
     
    sec_monkey and Asia-Off-Grid like this.
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