New User Transfer Switch Outback system question.

I purchased a Flexware 500 System (only one 48 volt Grid Interactive Inverter)

Got it all mounted today, waiting on Wednesday for the electrician to come and hook everything up.

After reading the instructions a dozen times and see alot of diagrams about HOW everything is supposed to be hooked up, I am wondering if I am doubling my effort with the AC flexware box.

I already have a Transfer switch installed as I have a backup Genny. We are going to put the genny on a manual transfer switch as to not feed the inverter/grid when not needed.

So do I just need to do the ac Input/outputs directly from the inverter to the ALREADY installed transfer panel?

If so, what about the bus bars inside the AC Flexware box?

Does the genny go directly into the current transfer panel or the flexware ac box?

Being that the inverter is the INTERACTIVE one, does that mean I don't need to worry about the batteries being charged? The inverter (when sensing that their is grid power or genny power) will start charging the batteries automatically?)

Total confusion for me on the AC side of things. Any help would be great!

Thanks
DTT

Comments

  • RCinFLA
    RCinFLA Solar Expert Posts: 1,484 ✭✭✭✭
    Re: New User Transfer Switch Outback system question.

    First, I am not super familar with the Outback system.

    The basic operation is the inverter operates in parallel with grid once grid syncronization is achieved by inverter controller.

    There is not a transfer switch, per say, within the inverter. There is a 60 amp SPST relay that opens the connection between the ACin and ACout. Inverter is permanently connected to ACout. When grid syncronization is achieved the relay is closed putting the inverter in parallel with the grid, connecting ACin directly to ACout.

    Normal hook up is to install a sub-panel on ACout that has AC breakers for loads you want to maintain during grid outage. The sub-panel can contain loads exceeding the 30 amp output maximum of inverter but it is assumed that manual management of loads is done to avoid overloading inverter. If overloaded the inverter will shut down. The relay connecting to grid is rated at 60 amps AC max. When grid goes down the controller detects it and opens the input relay allowing the inverter to pick up ACout loads.

    As to battery charging, the inverter is bi-directional in that power can flow from grid to batteries or batteries to ACout. The pulse width modulation of transformer primary side controls the voltage level on secondary of transformer (ACout). A slight modification of PWM sequence can raise or lower the voltage output. In this way the inverter can push power to ACout/grid or pull power from grid to charge batteries. When grid is present, some of the ACin current is consumed by inverter to charge batteries. It will immediately cease charging and produce output to ACout if grid goes down.

    The Flexware 500 System is just a package that helps enable getting approval from electrical inspectors for grid tied setup. It includes a transfer bypass switch to take the inverter box out of the path from main panel to sub-panel. This is good to have if there is a problem with the inverter that requires it to be taken out of the rack for servicing.

    Now for the bad part, if you want to run from a generator you probably should not have purchased the GT version of inverter. The GT version has a restricted input frequency tolerance (-0.6 Hz, +0.5 Hz) that most generators have a hard time meeting. The normal FX version is grid tied for charging and power passthrough to ACout just like GT version but allows a wider input frequency for generators (about +/- 5 Hz), it just is prohibited from selling power back to grid by software within unit.

    If you have an inverter/generator like a Honda EU3000i or Yamaha EF3000i they will work because their DC alternator to sinewave inverter system is very accurate in controlling line frequency.

    The GT version allows selling from battery line. If a solar charge controller tries to raise battery voltage above inverter charger voltage setting the inverter will suck off excess power and push it to grid/ACout loads. The regular FX version will push excess power to grid/ACout node, but if ACout loads don't consume all the solar power it will not allow excess power to be pushed out to ACin port.
  • t00ls
    t00ls Solar Expert Posts: 245 ✭✭✭
    Re: New User Transfer Switch Outback system question.

    after reading about the gtfx...it specifically states that it is not designed to be used with a generator ....therefore i have removed the image as not to confuse anyone

    there are other ways to use the generator , you could get an iota
    charger/ controller or something similar that will charge from any ac source...so while the power is off , your batteries stay charged

    again...I would need more info on your complete system to give you an informed opinion
  • RCinFLA
    RCinFLA Solar Expert Posts: 1,484 ✭✭✭✭
    Re: New User Transfer Switch Outback system question.

    You did not mention the type of generator you have.

    Is the transfer switch rigged on the incoming grid mains before the breaker box main cut off breaker?

    Do you plan to put in a solar array to sell back to grid?

    If you do not intend to sell to grid you can probably swap out the GTFX for FX.

    Unless you have an inverter/generator you will likely have problem with GTFX locking onto and maintaining lock on the generator.