How do I wire a GTI system with an AC GENERATOR, anyone here got a simple diagram... what do I need?

ChanChan Registered Users Posts: 45 ✭✭
How do I wire a GTI system with an AC GENERATOR, anyone here got a simple diagram... what do I need?

ATS?

Comments

  • BB.BB. Super Moderators, Administrators Posts: 29,485 admin
    Do you expect the GTI solar (Grid Tied Inverter) to work with the genset when the utility power has failed (or want to do an off grid genset+GTI)?

    In general, it will not work. The GTI does not support (add its power) to the genset for several reasons.
    1. GTI is not regulated. The GT Inverter simply takes all of the energy from the solar array and pumps its into the local AC wiring. If the GTI output exceeds the local AC loads--There is no place for the energy to go other than "backwards" through the geset alternator. At that point the local AC voltage will exceed the GT inverter's maximum and will cause the inverter to shut down (5 minute timeout typical, then retry).
    2. For smaller AC Gensets with mechanical speed/RPM regulation, the output frequency is not stable/accurate enough for GT inverter (+/- 0.1 to 1.0 Hz or so). Again, if the frequency is "wrong", the GT Inverter will shut down for 5 minutes and retry.
    If you are looking at large AC gensets--You might find a system that does work with GTI solar. That is outside the experiences of most of our people here.

    The typical way home/small business systems do Grid Tied and Off Grid solar is to use a "Hybrid" inverter (does both off grid and grid tied) with a battery bank. This is for systems that are in the range of 4 kWatt to 8-30 kWatt (typical--You can connect many hybrid inverters together for a much larger system too).

    The system looks like: Solar panels -> solar charge controller -> battery bank -> Hybrid Inverter -> local AC backup power panel

    And the AC side: AC mains -> Hybrid Inverter AC1 input -> local AC backup power panel
    And AC genset: AC genset -> Hybrid Inverter AC2 input -> local AC backup power panel

    The the utility mains are up; The solar power both charges the battery bank and any excess power is sent to the AC mains (for use by local loads and "backwards" to the AC mains).

    When the AC mains are down; The solar power charges the battery bank and solar+battery supplies the AC local backup power (Hybrid inverter has its own AC transfer switch to disconnect from the AC mains).

    If the battery bank needs charging: The Hybrid inverter will start the genset and enter "Generator Support Mode". The genset will supply AC power and the hybrid inverter will take any excess genset power and recharge the battery bank. If the AC load exceeds the genset AC output rating, the hybrid inverter can take battery+solar power and "help" (or "support) the genset output AC output (i.e., the system will support a maximum power of AC Genset+Hybrid Inverter power ratings).

    The downside--You need a large DC battery bank. You have the costs and maintenance of a battery bank. And batteries need to be replaced every 5-10 years or so.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • ChanChan Registered Users Posts: 45 ✭✭
    I mean, How do I attach a GTI so that when there is no GRID, then the GTI will turn off, while there is still power thru GENSET.
  • mike95490mike95490 Solar Expert Posts: 8,369 ✭✭✭✭✭
    The GT inverter will sense the loss of the grid and shut off
    The average genset is not stable enough to re-activate the GTI, but inverter gensets may trigger it,

    You will need to install a Generator Transfer Switch
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

  • ChanChan Registered Users Posts: 45 ✭✭
    can you give me a simple diagram?
  • mvasmvas Registered Users Posts: 336 ✭✭✭
    edited December 2016 #6
    Automatic Transfer Switch Diagram ...
    http://www.smps.us/connecting_generator.GIF

    Connect your GTI output to the Main Service Panel via dedicated breaker, ie normal connection.

    Upon loss of AC Grid ...
    1) The GTI will automatically shutdown
    2) The ATS will automatically start the Generator
    3) The ATS will switch the House Loads to the Generator.

    When AC Grid is restored ...
    1) The GTI will automatically restart
    2) The ATS will automatically switch the House Loads to the AC Grid
    3) The ATS will automatically shutdown the Generator

  • ChanChan Registered Users Posts: 45 ✭✭
    Thank
Sign In or Register to comment.