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Dumb Question Regarding the Growatt 12kW 48V 250VDC 120A Off-Grid Inverter

The write-up at watts247 explains how to arrange your array. Or you can buy an external solar controller:

Solar Panel Configuration:

120A (7kW) Solar MPPT Charge controller (60Vmp to 245Voc) – Max 250V
Number of panels you can connect = 7000W / [your panel wattage] – example 7000 /345W = 20 panels , 7000 / 240W = 30 panels etc

if your Solar panels’ Vmp (Voltage at maximum power – the lower of the two numbers on your panel spec) (Not Voc) voltage is between 38.3 V and 57.5V, you can connect 4 in series with matching parallel strings to add up to the number of panels as in formula above. 20 x 40V panels would be connected in 4s3p (12 panels) on one input and 4s2 (8 panels) on the other

If your Vmp is between 28.75V and 38.3V you can connect 5 in series with matching series strings connected in parallel to add up to the number of panels as in formula above. example: 30 x 35V panels would be connected in 5s3p on each PV input (15 panels each)

If your Vmp is between 17V and 28.75V, then 6 in series with matching series strings connected in parallel to add up to the number of panels as in formula above. example 72 x 20V panels(maybe 100W) would be 6s6p (36 panels) – but remember there a 2 PV inputs so each input will be 6s6p and 6s6p
 
@BMcL Thanks for that link. Makes things a little more clear. But still, not a lot of info (unless I'm not seeing it) about the 2 PV inputs on the Growatt 12kw. Do I need to use both to get the full 120a charge from the CC? If I can just use 1, I would not have to make 2 home runs from the array and would not have to buy 2 combiner boxes. (although I realize with only 2 parallel strings on each of the 2 PV inputs to the inverter, I probably would not need combiners are the array at all, just fuse the whole array inside the solar shed before the inverter.)
 
So 48v x 0.84amps ... you're seeing 40ish watts of idle draw. Nice. Thanks so much. Very helpful. My goal is to do the pre order today of the 12kw and 16 440w panels for an array.

Does your inverter have the 2 PV inputs? the 12kw has 2 PV inputs but no where in the manual does it say much about it. I'm wondering if that means it is actually 2 60amp MPPTs instead of 1 120 MPPT. Seems like that would mean Id need to split my array into 2 arrays, which is not a big deal as I was planning to do 3 different orientations. A SSW / S / SSE. I also wonder if with this orientation If could exceed the 7000w array size spec of the 12kw (noted in the manual) if I kept it to 200vdc? I would really like to add 1 more series group to the SSW orientation and 1 more series group to the SSE orientation, making it a total 10560 watt array.

But Still unclear what the 2 PV inputs on the Growatt 12kw are specifically.

But here is my basic idea
View attachment 68917
Are you looking at the NEW latest manual - for the MVP one.
 

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  • NEW-Growatt SPF 4000T-12000T DVM User Manual.pdf
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@Joe BoyKey No I had not seen that one. I downloaded the one from Signature Solar on the inverter page. The one you've posted is better, but still not saying much about the 2 PV inputs. For the 12kw it simply shows connecting both PV1 and PV2 with on explaination unless I am missing it. Are there 2 MPPT trackers in the 12kw? Does each only do 60a x 2 ??

And again unless I am missing it, this new manual does not seem to indicate a total array size. I am not sure why the array size would matter as long as you did not exceed the input VOC even for extreme conditions. Most MPPT CCs will let you go crazy big and simply not use it if they dont need it.

But I am thinking I can at least do this ....
Array Layout Design.JPG

But not sure if I can do This ...
10k Array.JPG
 
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@Joe BoyKey No I had not seen that one. I downloaded the one from Signature Solar on the inverter page. The one you've posted is better, but still not saying much about the 2 PV inputs. For the 12kw it simply shows connecting both PV1 and PV2 with on explaination unless I am missing it. Are there 2 MPPT trackers in the 12kw? Does each only do 60a x 2 ??

And again unless I am missing it, this new manual does not seem to indicate a total array size. I am not sure why the array size would matter as long as you did not exceed the input VOC even for extreme conditions. Most MPPT CCs will let you go crazy big and simply not use it if they dont need it.

But I am thinking I can at least do this ....
View attachment 68925

But not sure if I can do This ...
View attachment 68926
You need to send these pics to James at Sig Solar for a blessing and ask your questions - james@signaturesolar.us
 
While I'm waiting on a response about the array , I'm taking measurements off my MidNite Solar SW E-Panel I have here . This is an enclosure that is 15.25 wide x 16.25 tall x 8.8 deep. Got to reading the spec of the growatt 12kw and it appears this enclosure would be a near perfect fit for the bottom of the 12kw with the e-Panel turned sideways and mount to the bottom of 12kw.

Bennifits
1. Includes a 250 amp DC battery breaker
2. Has several busbars for connecting incoming wire
3. Several knockouts
4. Space for 6 din rail ac or dc breakers and 3 panel mount breakers (not included)
5. Plenty of face space for display accessories
6. Includes a shunt.

Only issue I can see would be the exact mate up of the battery bars but this would be easily over come by just making up your own short cables.

Looks like it could make for a quick, easy, clean install.

Capture+_2021-10-15-14-41-06~2.png


Capture+_2021-10-15-14-41-30~2.png
 
Hi Guys.
I am from austria (europe) and i want to buy this inverter. How can i hook it up to our grid, when we have only 240V (L1, N and Ground). I can only find HOT1 and HOT2 in the discription. Sorry for this questiion, Markus
 
Growatt LF inverter (as like AIMS and others) do not check for grid L1-N and L2-N voltage imbalance. As a result, they cannot safely have grid neutral connected to inverter neutral. 99% of the time it is not a problem but when it is it can create too much current in inverter output transformer and damage inverter. Units like Xantrex, Outback, and Magnum check for grid L1-N and L2-N voltage imbalance and will release from grid if too much inverter output neutral transformer current is created by an unbalanced grid connection.

Growatt recommends only connecting AC input to 240vac. The output transformer has center tap that creates the split phase 240/120vac. Not allowing grid neutral connection makes the unit non-compliant to be connected to U.S. grid.

One other error user sometimes do is loosen both screws on terminal strip and shove their wire deep into connector. The top screw is for the wire from internal to inverter and you can eject the wire inside inverter if you loosen both screws and shove external wire in far enough.

With inverter running you should have 120vac from AC output N connection and Hot 1 or Hot 2. The N connection is tied to inverter output transformer center tap.

SPF6000-T AC hookup.png

Growatt LF All-in-One inverter's SCC controller outputs directly to inverter battery terminals. (option 1 in below diagram)

LF hybrid inverter block diagram.png
 
Hi Guys.
I am from austria (europe) and i want to buy this inverter. How can i hook it up to our grid, when we have only 240V (L1, N and Ground). I can only find HOT1 and HOT2 in the discription. Sorry for this questiion, Markus
The “North America Specific” version is 120/240 volt only and is not compatable with euro 230 volt use
There are euro/asian versions that are specifically designed for 230 volt service

Please dont make the mistake in trying to use a 120/240 volt “split phase” version for single phase use OR use the euro/asian 230 volt single phase unit for use in north america on a 120/240 split phase grid

They were not designed for that
 
I do agree that their wording in the manual does not state it will work, but the advertisements do say split phase...

I was close to buying one but haven't.
I wouldn't buy one. Busbars are way to small to fit correct wire size. You need a 4awg for 80input. You cant break off strands to make it fit as its against code and unsafe as loose strands can arc over time and cause heat issues. Inverter Breakers are unlabel so you must use 60c wire amperage chart even if your using 75 or 90c wire. 75c is common for household breakers/panels. But again inverter breakers are unlisted so must use c60 amperage chart. Or at least unit I had for a client had breakers unlabeled. Which means you can't use 6awg wire as it rated only at 55 amps. You would need bump it up to 4awg wire.
I just pull breakers and put 2 pole ul rated 75c breakers in with larger busbars in to accept 4awg for input (80a) output is (63a)
 
I wouldn't buy one. Busbars are way to small to fit correct wire size. You need a 4awg for 80input. You cant break off strands to make it fit as its against code and unsafe as loose strands can arc over time and cause heat issues. Inverter Breakers are unlabel so you must use 60c wire amperage chart even if your using 75 or 90c wire. 75c is common for household breakers/panels. But again inverter breakers are unlisted so must use c60 amperage chart. Or at least unit I had for a client had breakers unlabeled. Which means you can't use 6awg wire as it rated only at 55 amps. You would need bump it up to 4awg wire.
I just pull breakers and put 2 pole ul rated 75c breakers in with larger busbars in to accept 4awg for input (80a) output is (63a)
Do you have a thread showing this? I am still researching. I saw a video where Will said 4 AWG, but there is NO way 4 AWG will fit. I feel more comfortable with 4 AWG and I already purchased the 12kw, so I am very interested in how you did this. My input breaker is labeled but not too sure about the output breakers.
 

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I installed my new 12kw 48V Growatt Inverter today and I am not getting the expected output.

The manual says for 240V installation to NOT hook up the Neutral wire from the output. I get 240V across H1 & H2 but only 75V from H1 to Neutral/Ground and 75V from H2 to Neutral/Ground. Is something wrong with the inverter? How do I get normal USA 120V on both H1 & H2 for our normal single phase 120V + 120V = 240V USA electricity?
Signature solar just told me the intructions are incorrect. “Yes, Lelia is correct. The Growatt instructions are poorly written and this particular manual was created for the European market where they only have 230v appliances. ”
“The ground that you are referencing is the system ground. What you will do is take your L1, L2, neutral and ground out from the unit to your service panel where your neutral-ground bond will be made.”
 
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