Two inverter systems, One generator

mike760mike760 Registered Users Posts: 37 ✭✭
I have maxed out my first off-grid conext inverter system so I have added a second one.  Each obviously has its own load/breaker panel with independent branch circuits.  I have one generator that has the capacity to supply both systems.

Since there is a generator in the configuration, the neutrals will be tied together from both inverter systems and the generator.  Does this create a problem?

Comments

  • RCinFLARCinFLA Solar Expert Posts: 1,399 ✭✭✭✭
    No problem as long as they are groundable neutral inverters.  I run four hybrid inverters fed by one generator.  Just make sure AC gen input max  AC currents limits are set and distributed between inverters so generator maximum power is not exceeded.
  • BB.BB. Super Moderators, Administrators Posts: 32,027 admin
    This is what the manual says:

    https://www.solar-electric.com/lib/wind-sun/Conext-SW-120-Install-Guide.pdf

    See page 1-23 (PDF page 41) for neutral/ground bonding instructions (sorry, cut and past don't work well on this computer).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • mike760mike760 Registered Users Posts: 37 ✭✭
    So according to the manual, it is my understanding that I should leave the generator as it is with a floating neutral and then only one of the breaker panels should be bonded even though they operate as two separate inverter systems.  
  • BB.BB. Super Moderators, Administrators Posts: 32,027 admin
    The neutrals are carried throughout the system (common connection to all neutrals). This unit does not "switch" the Neutrals (i.e., between AC1 and AC2). So only one Neutral to Earth Bond is needed (typically bonded in one of the main AC panels. And "lifted" N+G bonds anywhere else--Genset, other AC inverter, etc.).

    Do you have any GFI outlets (such as on the Genset AC output)? If you, for example, had a N+G bond inside the genset, ran AC from genset through its GFI outlet(s), then to the AC main panel (or AC2 on the inverter) and have a second N+G bond (AC main panel, elsewhere)--Then the GFI will probably trip because there is a N+G before the GFI input and another N+G after the GFI outlet (parallel current path between Neutral(s) and Green wire ground/metal conduit--Which will trip the GFI because L1 output is not equal and oposiste of Neutral current).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • mike760mike760 Registered Users Posts: 37 ✭✭
    Agreed, all neutrals are common and not switched.  Only one N/G bond in the system which is located in the main breaker panel for the first inverter system.  The generator and second breaker panels have a ground but it is frame only, no bond.

    I do have one GFI receptacle on a sub panel which is connected to the main panel of the first inverter system.  I have not experienced any false activations so far.
  • BB.BB. Super Moderators, Administrators Posts: 32,027 admin
    N+G bond before the GFI is standard.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • mike760mike760 Registered Users Posts: 37 ✭✭
    Thanks for the info and the link!
Sign In or Register to comment.