Grid tie inverters

[TinMan]

I have found an excellent deal my local electronics supplier has ATM -A 1.5kVA grid tie inverter. Normal price is $1399.00 AU dollar's,and on special ATM for only $165.00 AU.
http://www.altronics.com.au/index.asp?area=item&id=M7977

My question is this-dose a grid tie inverter have to be conected to the grid to work?-dose it need the 240 volt ac(in my case)signal to opperate. Or can i use this as a normal inverter off grid?.

Thanks
Brad

[e2matrix]

Most inverters that can run off just DC input and provide power to your home etc.   If they say grid tie it just means they are able to sink to the grid frequency and be able to sell back power to the grid.   However some grid tie inverters are made only to sell back power rather than provide power to your home or other things.   I don't see that $165 price right now - maybe it was a mistake.   The $1400 is actually quite a lot for a 1.5KW inverter but $165 is almost unimaginably low if it's grid tie.   Not sure where you are but a place in Florida normally has some good deals on high quality Trace / Xantrex inverters of many types including grid tie.   

[ion]

Anybody have any good quality schematics of grid tie inverters? I've got a few ideas to try out, but would first like to see what the pro's in the business are doing.

[TinMan]

Most inverters that can run off just DC input and provide power to your home etc.   If they say grid tie it just means they are able to sink to the grid frequency and be able to sell back power to the grid.   However some grid tie inverters are made only to sell back power rather than provide power to your home or other things.   I don't see that $165 price right now - maybe it was a mistake.   The $1400 is actually quite a lot for a 1.5KW inverter but $165 is almost unimaginably low if it's grid tie.   Not sure where you are but a place in Florida normally has some good deals on high quality Trace / Xantrex inverters of many types including grid tie.   

Hi e2matrix.
The price is correct,they are having a sale on at the moment.On another forum ,it was mentioned that they must recieve the grid's AC signal to opperate. This is some sort of safty measure,so as if the power company is working on the line's,and has them isolated,the grid tie inverter cannot pump power back into the line.
By the way,i am in Western Australia.

Thanks for your reply.
Brad

[TinMan]

Anybody have any good quality schematics of grid tie inverters? I've got a few ideas to try out, but would first like to see what the pro's in the business are doing.

Hi ION
Im still hunting for a schematic,but as yet,cant locate one.My idea was to use it on our caravan(i think you guys call them trailors). At this price,i think it is a great deal,and far cheaper than a 1.5kw of grid inverter.I will keep looking for the schematic,but here is some spek's on the unit.
•Altronics - M7977 PV Grid Feed Inverter - 1.5kVA
inverters are specially designed for small to medium roof top solar power generation systems Each model features Sealed stainless steel enclosure designed and certified for IP65 protection Suitable for both indoor and outdoor installations High efficiency isolation transformer between the inverter electronics and the utility grid for safety and reliability All external connections ie DC input AC output communucations are mutually electrically isolated Easy field wiring via plug in connection for DC input AC output communication cables MPPT maximises the power yield of the array string Transient voltage suppressor at both input and output terminals to protect the inverter from high transient voltages induced by lightning or other sources LCD readout displays operating parameters including voltage of each PV array electricity generated power generation time internal temperature date time operating modes system errors Highly efficient throughout its operating range of 25 C to 50 C Three models are available 1 5kVA 2kVA and 3kVA 12 Month Warranty Specifications PV Input Power 1875W Max DC Input Power 1755W Max Input Current 10A MPPT Channels 1 Max AC Output Power 1650VA Max AC Output Current 7A Max Efficiency 94 Weight 27kg Dimensions HxWxDmm 344x415x205 Approvals Safety IEC 62103 2003 EN50178 1997 Grid

[TinMan]

ION

Here is some info i found,with a simple schematic,that tells how and why the GTI detect the AC mains signal.
http://solar.smps.us/grid-tie-inverter-schematic.html

My other question is-are the GTI a pure sign output?

[bte]

http://arrow.dit.ie/cgi/viewcontent.cgi?article=1136&context=engscheleart

Grid Tie inverters sometimes try to fight the grid and shut down if they win. The above is a newer way to detect islanding. All grid tie inverters must produce a pure sine wave and sync to the mains near perfectly.

[e2matrix]

I have found an excellent deal my local electronics supplier has ATM -A 1.5kVA grid tie inverter. Normal price is $1399.00 AU dollar's,and on special ATM for only $165.00 AU.
http://www.altronics.com.au/index.asp?area=item&id=M7977

My question is this-dose a grid tie inverter have to be conected to the grid to work?-dose it need the 240 volt ac(in my case)signal to opperate. Or can i use this as a normal inverter off grid?.

Thanks
Brad

Based on some discussion on another forum (maybe that's the one you referred to above) I will add that from my personal experience my first post is largely correct but in seeing the post from a member of another forum I was reminded that most current grid tie inverters DO need to see power from the grid in order to operate.   Ones I have owned in the past did not need that and could even feed back to a down grid (a dangerous situation) if they were programmed that way.   But new laws have made it mandatory apparently for grid tie inverters to need to see power from the grid in order to work.