Growatt SPF 12000T DVM MPV vs 2x EG4 6500EX-48

ColtB45

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Hi, I'm new here. I am planning my DIY solar system and seeking advice on which inverter to go with. I am undecided between the Growatt SPF 12000T DVM MPV & 2 of the EG4 6500EX-48.

The goal is to use the system as a UPS of sorts with solar/battery being the preferred input and only switching to utility when I drop below a minimum level of charge. Price between the 1 growatt and 2 EG4s is ~$300. There will be a large surge load (3 ton HVAC with soft-start kit [LRA can get as high as 60A @ 240V]). Today I am able to run the entire house with a 8KW genset and start the HVAC about half the time. Obviously there is some load management when on genset (we wont run the electric dryer, water heater, or oven at the same time) but otherwise it works.

Other things to consider:
Starting with 6KW of PV with later plans to scale up to 18KW (this will also require additional MPPT controllers).
I plan on starting with 3x EG4 5.12KW batteries with later plans to scale this up to 6.

Any and all input is appreciated!

Thanks,
-Colt
 

ColtB45

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Thanks for not being biased 😅 and thanks for responding!

One of the things I cant seem to find is bypass capacity. If the inverters are in bypass, how much amperage can they pass from utility?

Also, the surge/overload numbers on the growatt are confusing. It claims 300% (36KW) for 5 seconds on page 11 of the manual. But on page 30 it also claims 36KW but only for 20ms. Which is to be believed?
Depending on which number is accurate 5s or 20ms, the EG4 may be less robust in the overload department as they only claim 150% (19.5KW) for 5s.

What is the opinion on overload capacity ( as it relates to motor start), are these numbers to be believed?
 

shopman

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The Growatt is a low frequency inverter with a hefty iron core transformer that can absorb the surge from motor starts. I believe the Eg4's are high frequency inverters so they won't be as robust in that department.
 

WYtreasure

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Hi, I'm new here. I am planning my DIY solar system and seeking advice on which inverter to go with. I am undecided between the Growatt SPF 12000T DVM MPV & 2 of the EG4 6500EX-48.

The goal is to use the system as a UPS of sorts with solar/battery being the preferred input and only switching to utility when I drop below a minimum level of charge. Price between the 1 growatt and 2 EG4s is ~$300. There will be a large surge load (3 ton HVAC with soft-start kit [LRA can get as high as 60A @ 240V]). Today I am able to run the entire house with a 8KW genset and start the HVAC about half the time. Obviously there is some load management when on genset (we wont run the electric dryer, water heater, or oven at the same time) but otherwise it works.

Other things to consider:
Starting with 6KW of PV with later plans to scale up to 18KW (this will also require additional MPPT controllers).
I plan on starting with 3x EG4 5.12KW batteries with later plans to scale this up to 6.

Any and all input is appreciated!

Thanks,
-Colt
If you can, please post here the MAX SOLAR DC AMPS, as well as your SOURCE. I have not found the magic number anywhere.

I am aware of the 7000W & 250V limitations.
 

WYtreasure

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Specs
120A

Manual @ page 10
120A

It only makes sense that's divided by two with a max of 60A on each of the 2 PV inputs.
Thank you ColtB45.
I have never seen the term "Typical Amperage" used to refer to "Max Solar/PV Input Amperage". I see 120A on page 10 of the manual which is available at growatt-america.com, (my user manual has the same info on page 11).
I thought "120A" was the DC Circuit Breaker size being suggested in the "CAUTION" under "PV Connection".

Apparently it is a coincidence that on page 12 the "MPPT Charging Current" is equal to the "Typical Amperage".

The Specs refer to the 120A as "Maximum PV Charge Current" under the heading of "Solar Charger" so I assumed that was the battery charging maximum.

I'm confused by the terminology.

Perhaps someone using the SPF 4000T to 12000T DVM-MPV could share their PV Input Amps.
 

timselectric

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The Specs refer to the 120A as "Maximum PV Charge Current" under the heading of "Solar Charger" so I assumed that was the battery charging maximum.
Yes, this is the battery charging current, produced by the solar charge controller.
 

ColtB45

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I just had a chat with growatt-america and confirmed the Max PV Input Amps. 120A is lots of input.
Are they a separate entity from Signature Solar or one and the same? I was curious if I bought a Growatt outside of SS if there would be any stateside support.
 

WYtreasure

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Are they a separate entity from Signature Solar or one and the same? I was curious if I bought a Growatt outside of SS if there would be any stateside support.
Growatt-america is the manufacturer I THINK.
I believe the answer to the support question is a BIG NO. I think SS is the only US dealer for Growatt. Buy from someone besides SS & support ain't so good. EDIT: My mistake about about support. Sorry to watts247.

SPF 6000T-12000T DVM-MPV Manual
Quoc Le was very helpful, be patient, in the pop-up chat window.
 
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timselectric

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Are they a separate entity from Signature Solar or one and the same? I was curious if I bought a Growatt outside of SS if there would be any stateside support.
If you buy a Growatt from anywhere other than SS, it won't be the US version. (No need to ask me how I know lol)

Edit: scratch that, different model.
 

Kornbread

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IIRC, Ian from Watts247 is in Utah, and sells Growatt. Are these not US versions? Ian will also tell you how to properly wire the unit to the grid. Cannot get that from SigSolar!

To recap from earlier, if you plan on growing to 18k, the 12k is not stackable, but it does have a nice surge rating. Not sure what your consumption is, but I'd wager you'll need more than 30kwh of reserve, unless plans are to supplement with genny. Maybe check out filterguy's energy audit.

Where in Arkansas?
 

RichardFromEG4

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IIRC, Ian from Watts247 is in Utah, and sells Growatt. Are these not US versions? Ian will also tell you how to properly wire the unit to the grid. Cannot get that from SigSolar!

To recap from earlier, if you plan on growing to 18k, the 12k is not stackable, but it does have a nice surge rating. Not sure what your consumption is, but I'd wager you'll need more than 30kwh of reserve, unless plans are to supplement with genny. Maybe check out filterguy's energy audit.

Where in Arkansas?
Ian is literally the only other person I would even think about buying a Growatt from outside of Signature Solar. He definitely does things a little different so it all depends on what you prefer.
 

Kornbread

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Pretty close to Searcy
~3hr drive.

If you're new at this, Filterguy has a sticky in beginner's resource page that may be very helpful. Lot to digest in there. WYtreasure may have poked around in your thread, but he can be very helpful.

If you plan to connect to the grid, contact your local elec coop first and ask about their regulations regarding consumer generators. They may have some regulations that prove costly. Some are more solar friendly than others.

I see you were looking at Oldsawman's spf12k. You might find his post, that I later hijacked, interesting growatt 12 passthrough
 
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SignatureSolarJames

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So here are the comparative pros of each:
EG4:
-500v PV input means no combiner boxes needed and wire is 10awg, very cost effective and less labor
-8kw each in solar means you are set for up to 16kw
-13kw is better than 12
-91-94% efficiency vs 88% for LF
-Stackable is better than not
-208 3 phase capable, (hey that's cool!)
-wifi included with remote settings change
-UL1741 if the grid company comes whining
-I've lived off either, the surge on the 6500 is good, see the recent video with the 15A air compressor startup
-Shipping is dirt cheap
-3-5Year warranty depending on battery type vs 2 year on growatt
-Won't break your spine installing them (medical work savings $$)

Growatt:
-cheaper and easier to repair (higher failure rate in the early days but improving)
-MPPT voltage starts at 60v vs 120 if you are planning to only use a few panels
-cheaper overall cost (but you'll lose the perceived savings on freight, Wifi and buying an extra 7kw MPPPT to compete. Plus, wiring and combiner increases could be $400 before you consider your labor value. I would say as an installer I would view this approach as a loss of money for a new system)
-set to the voltage range of older systems for drop-in replacement
-One unit is kind of sexy (broken backs are not as much tho)

We carry both and would be happy to assist with either. lmk if I missed anything
 
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