Parallel Operation in Split Phase

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Panapat
Panapat Registered Users Posts: 15 ✭✭
in Off Grid Solar & Battery Systems #1
I am getting close to installing my 6 kWh off grid system. Its comprised of two 3 kWh multi-functional inverters running in parallel, and two 10 kWh lithium battery packs. This is how they are supposed to be wired. As you can see it doesn't show the neutral tied to ground. But it also has a dry contact on each inverter which ties the neutral to ground via a grounding box whilst on battery power.   My question is, as I am totally off the grid can I not tie the neutral to ground in my distribution boxes? Here in Panama we "follow" USA code.
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  • Estragon
    Estragon Registered Users Posts: 4,496 ✭✭✭✭✭
    #2
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    Generally speaking, you wouldn't want a N/G bond in multiple places.  If I'm understanding your setup, this would be the case while on battery with bonding done both at the inverters and in the distribution panel.

    If the inverters lift the bond when not inverting, you might bond at generator (if not already bonded)?

    Off-grid.  
    Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
    Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
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  • Panapat
    Panapat Registered Users Posts: 15 ✭✭
    #3
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    I don't have a generator. The supplier said I should bond at the first distribution box. The GE panel I am using provides a screw to bond the neutral to the case. The others will remain isolated as you suggested.
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  • Estragon
    Estragon Registered Users Posts: 4,496 ✭✭✭✭✭
    #4
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    I may be misunderstanding.  If the inverters are designed to N-G bond on battery power, you wouldn't want a second bond at the disconnect/distribution box as well.

    Is it possible the inverter dry contact bonding is or should be disabled in an application with dual inverters?  If so, bonding would normally be done at the first disconnect.

    Do you have a link to the inverter?
    Off-grid.  
    Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
    Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
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  • Panapat
    Panapat Registered Users Posts: 15 ✭✭
    #5
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  • Panapat
    Panapat Registered Users Posts: 15 ✭✭
    #6
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    I don't have a link to the manual but this is what it says about Neutral and Ground using the dry contact. Engineers say that I can disable the dry contact, which is the default, and ground at the house box as you suggest.
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