Two different grid-tie inverter in 1 output? will it work? example...

ChanChan Registered Users Posts: 45 ✭✭
Will this setup work?

[img]http://i.imgur.com/CDH7aYX.jpg[/img]

Sample image @ http://i.imgur.com/CDH7aYX.jpg

Please help



Comments

  • BB.BB. Super Moderators, Administrators Posts: 31,063 admin
    I guess you may be in the Philippines?

    Functionally, it would work... However, from a wiring/code point of view--You should make a sub panel (say 40 amp branch circuit to to sub panel, then 2x 20 amp circuits--One to each GT inverter). Generally, it is not a good idea to "daisy chain" your AC power from GT inverters (you have to have heavy enough rated wiring/breaker for the wiring back to the main panel to carry current from both GT inverters).

    I assume your main panel is "full" and you do not have room to add two GT solar circuits?

    In the US, we have "slim breakers" that can give you two branch circuits per breaker position... You could possibly get extra breaker space to add two solar branch circuits instead of one.

    And a comment on your drawing... You have double pole breakers on your main panel drawing, but only a single pole breaker on your "jumper" to the second GT inverter--I do not know anything about Philippine power to a home (or small office). Do you  have 120/240 VAC power, or 220 VAC with a "hot and neutral" connection (only need single pole breaker)?

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • ChanChan Registered Users Posts: 45 ✭✭
    We have a 220AC here in the Philippines.... also I have updated the diagram....
    Will two different inverter with different WATTAGES help each other on lowering the DRAW from the UTILITY COMPANY?
    EXAMPLE:
    I AM RUNNING 5000W load....  one of my inverter is 2000W , while the other one is 1500W will the two inverter help while the excess 1500W draw  from the utility company?

    MAIN BREAKER IS 120A and has a branch out breakers to load with different amp rating...

    http://i.imgur.com/m893H4O.jpg

  • BB.BB. Super Moderators, Administrators Posts: 31,063 admin
    I am not sure the 10 amp breaker to the 2,000 watt GT inverter is large enough... At least in the US, we use a 1.25x derating factor. And you should use the low voltage of your mains to figure out the actual current draw. For example (if you have >2 kWatts of solar array and are maxing out the GT inverter).
    • Say 200 VAC is your minimum operational voltage:
    • 2,000 Watt GT inverter * 1/200 volts = 10 amps max continuous
    • 10 amps * 1.25 NEC (US National Electric Code derating for wiring/breakers) = 12.5 amps minimum => 15 am minimum circuit+wiring
    How a GT inverter works is it takes all the available energy from the solar array and converts it to 220 VAC @ 60 Hz, and pumps it into the main panel wiring. That is all it "cares about".

    At that point the energy flows either to the local loads, and anything left over goes out the meter and spinning the meter backwards (if allowed by your utility). If your loads exceed the local GT inverter's output, the utility supplies the "missing energy" and the meter spins forward as usual (charging you for the "missing energy"--And not charging you for the energy your GT inverter has generated).

    For all the world, the AC Utility Grid looks like a "giant AC Battery Bank"--And you are using energy from the AC bank or "recharging it"--Just like your car with a battery, alternator (generator), and your local loads.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • Dave AngeliniDave Angelini Solar Expert Posts: 5,501 ✭✭✭✭✭
    Also make sure you are legal to do this with your building department and utility. A not legal set-up can be worse than the utility getting upset.  I recently had some experience with a client who "bootlegged" a system in Jamaica. The power meters there were set that once you sold more than you consumed, The power bill went up.
    "we go where power lines don't" Sierra Mountains near Mariposa/Yosemite CA
     http://members.sti.net/offgridsolar/
    E-mail [email protected]

  • BB.BB. Super Moderators, Administrators Posts: 31,063 admin
    Yes--Sometimes called "revenue guard". People would plug their meters "upside down" for part of the billing period to run the meter backwards and save on their bill. Many new meters (have the option) will run "forwards" regardless of the actual direction of power flow.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • ChanChan Registered Users Posts: 45 ✭✭
    What I was questioning was, WILL THE TWO GRID-TIE INVERTER WORK as they are both of different IN BRAND AND DIFFERENT POWER?
  • BB.BB. Super Moderators, Administrators Posts: 31,063 admin
    Yes. the two GT inverters will work just fine (mix and match). A GT Inverter only "cares" about its local solar array and its connection to the utility/grid. They do not care about other GT inverters or how many (or how few) loads that you may have connected.

    The power will be consumed by your local loads (house hold loads), Any loads that exceed your GT output (from both inverters), will be supplied through your utility meter (the meter will just "turn slower" because of the help of the GT inverters).

    And any extra will go backwards through the meter to the utility (in many cases, unless you have a Net Metering agreement and the correct meter from the utility, the utility can charge you money for sending extra power back to them.).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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