XW inverter load sharing question?

Options
jeffkruse
jeffkruse Solar Expert Posts: 205 ✭✭✭
in Advanced Solar Electric Technical Forum #1
I am currently off grid using a Xantrex 4548 inverter. I am thinking of connecting to the grid since they removed the insurance requirements.

I would like to keep the whole house on ACout like it is now. I would like to connect the Grid to ACin on the inverter.

Will the inverter share/transfer the power accordingly?
Examples:
I am drawing 500W for the house and my panels are making 2000Watts, will 500W go to the house and 1500W go to the grid?
I am drawing 4000W for the house and the panels are making 1000W, will the 3000W come from the grid and not the battery?

Is it better to connect the house to the grid and then when the grid goes down switch to the inverter ACout. Does this provide the least amount of wear or is the wear on the inverter insignificant?
· Share on Twitter

Comments

  • BB.
    BB. Super Moderators, Administrators Posts: 33,439 admin
    #2
    Options
    Re: XW inverter load sharing question?

    Assuming that it is an XW Hybrid GT/Off Grid Xantrex inverter--Then you are correct in its Grid Tie operation.

    Normally you would connect the XW to the grid and the AC out to your "protected" loads. Normally, you would only connect those loads that you need to operate during a power failure.

    Depending on your home, that may be your whole home, or only a part of it (some outlets, lights, no electric hot water heater, etc.).

    The inverter can only output 4,500 watts sustained power--so your loads need to be less than that. The other issue is the battery bank and solar panels. You need to size those for your expected loads too.

    The Xantex XW has its own transfer switch. So, it would be redundant to put another transfer switch to put your loads on the main power then transfer over to the Xantrex manually--although, some people do that.

    Are you planning on installing a backup generator too?

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
    · Share on Twitter
  • RCinFLA
    RCinFLA Solar Expert Posts: 1,484 ✭✭✭✭
    #3
    Options
    Re: XW inverter load sharing question?

    Yes to both the questions.

    XW inverter syncronizes to grid then engages its AC1 relay to connect to grid.

    ACout is connected to inverter. When grid is present AC1 input relay closes and the inverter operates in parallel with grid.

    When grid goes down the XW inverter sees it as an overload and immediately opens the AC1 relay connecting grid. This allows the inverter to continue to supply the ACout loads, up to power limit of inverter.

    The AC1 to ACout pass through is rated at 60 amps max, limited by AC1 relay. The inverter is not able to back up this level of load so if you have a load greater then inverter capability on ACout subpanel the inverter will detect overload and shut down.

    If you set up to sell power, the inverter will draw off of battery line and push to grid/ACout node whenever the solar charger raises the battery voltage above the point you set. This is usually set at the float level of batteries.

    If ACout load does not consume all the available solar power the XW will push excess power to grid, assuming you have sell enabled.
    · Share on Twitter
  • jeffkruse
    jeffkruse Solar Expert Posts: 205 ✭✭✭
    #4
    Options
    Re: XW inverter load sharing question?

    WOW, that was quick. Thanks for the answers!

    My system has been running for a year now (off grid) and seems to be sized right with a little extra to spare. I can switch to the grid if I have too many cloudy days so I don’t have a generator.

    My questions have been answered with great explanations. Thank you so much. I owe you both a beer.
    · Share on Twitter

Categories