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Forum Index : Solar : Grid Tie Inverter??

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Boppa
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Joined: 08/11/2016
Location: Australia
Posts: 814
Posted: 04:59am 20 Sep 2018
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Grid tie inverter?

I'm not sure what to make of these...
If it is what is says, wow....

literally plug and play?

Would it hook up to any sine wave inverter and let you 'cascade' in an off grid application (ie plug 4 into a powerstrip and have 4kw available when the sun is shining?)

eta I got to admit, I wish the Chinese would get some decent proofreaders who actually know english... 1000walts???
Edited by Boppa 2018-09-21
 
Madness

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Joined: 08/10/2011
Location: Australia
Posts: 2498
Posted: 05:13am 20 Sep 2018
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Maybe they mean 1000 VOLTS

Seriously though have look on Gumtree there are lots of secondhand proper GTI's for less money than one of those that probably needs at least 50% derating.Edited by Madness 2018-09-21
There are only 10 types of people in the world: those who understand binary, and those who don't.
 
hotwater
Senior Member

Joined: 29/08/2017
Location: United States
Posts: 120
Posted: 03:57pm 20 Sep 2018
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These require some line voltage to turn on. That can be done with a small sine wave inverter.

Can I be there to watch when you hook it up to the inverter? These are designed to tie into a grid which can sink a lot of current. They keep upping the voltage till they draw the max current from the panels. There are types of inverters that will take back power and put it into a battery. Those that don't just feed it back to the power supply cap. Notice the operating AC range of that unit? It extends well beyond that. So what happens if you are lucky is the cap explodes and everything else survives. I was going to do what you intended on my system and avoid going thru the battery/inverter for additional power. Except, I have a very fast dump load that can put the excess into heating water. Decided instead to run a 60V inverter directly off the panels. Now I just have to figure out what to do with all these GTI I bought.Edited by hotwater 2018-09-22
 
M Del
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Joined: 09/04/2012
Location: Australia
Posts: 155
Posted: 08:58am 21 Sep 2018
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I saw some a while ago that look the same called Grid Connect, similar range of specs so probably the same unit with a different name. Lots bigger than an Enphase but designed to do the same thing.
No direct experience.

If the same item then not totally reliable.
From memory they do not shut off when line voltage dissapears, so are illegal in OZ.

Big red letters does not ship to OZ, then says it does ship in small print.
Bad Chinglish.

Mark
 
Warpspeed
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Joined: 09/08/2007
Location: Australia
Posts: 4406
Posted: 11:37pm 21 Sep 2018
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Hotwater has summed it up pretty well.

A normal off grid inverter just generates 230v and whatever load is connected just draws from the inverter whatever power it needs. Pretty straightforward.

A grid tie inverter is very different. If you have a 1Kw grid tie hooked up to 1Kw+ of functioning solar panels, it will FORCE that 1Kw out through its output. All of it!

The grid will absorb that 1Kw easily with a very slight voltage rise, no sweat.

If your system has less than 1Kw of load to absorb all of that output power, the output voltage is going to rise uncontrollably. The grid tie inverter should just shut down, but it may also fry any smaller inverter it is connected to.

Its o/k to connect a small grid tie to a much larger off grid inverter. The forced output power from the small grid tie can be absorbed by the larger inverter and flow back into the battery. Many people here are actually doing this, its a clever trick.

But going the other way, a monster grid tie inverter connected to a small flea powered off grid inverter is either just going to shut down from overvoltage, or fry the small inverter. Definitely not recommended.
Cheers,  Tony.
 
Madness

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Joined: 08/10/2011
Location: Australia
Posts: 2498
Posted: 12:32am 22 Sep 2018
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Backfeeding via an off-grid Inverter works very well with the H Bridge type inverters we have been building and some others but it does not work with all inverters. I have a couple Trace inverters that I retired about 18 months ago, these would work happily with a GTI connected until the GTI started making more power than the AC loads would consume. This resulted in some very horrible noises and the whole lot shutting itself down.
There are only 10 types of people in the world: those who understand binary, and those who don't.
 
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