Two Growatt 3000TL LVM-ES, one 5000ES-US or one MPP LV6548?

timselectric

If I can do it, you can do it.
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Feb 5, 2022
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The Growatt is still hanging on my wall waiting for me to take it off and throw it in the rubbish,
I can dispose of it for you. And I will pay the shipping.
Especially if it's the US model from Signature Solar.
I'm interested in taking it apart and running some tests.
 
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MT off grid

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Jan 23, 2022
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Read thru the responses, this reminds me of the mainstream media and how they put out "misinformation". It's all about whatever narrative they want to present to get a desired result. Have we really gone down that rabbit hole?

If you will have the inverters powering loads 24/7, there is isn't an "idle draw", it's part of running your system on solar power. I have a baseload in my house of 150W constantly, it will require the units to be on 24/7.

I have 2 LV6548's, not installed yet but getting closer by the day when I get time to work on the project. A few things to keep in mind, if you ever plan on system expansion, go with the larger inverters. I have a SPF3000 in my truck camper, it works fine for that use, I would only use one in a house for a critical loads panel.

All of these units bond N-G under inverter power, unless you purchase the GW SPF5000 from Signature Solar. I'd steer clear of that unit anyway, plenty of choices that would be better if you want 240V split phase in a single unit like the LV6048. As for the N-G bond, really the correct place for it is at source which is the inverter. Installing a 3 pole double throw transfer switch is highly recommended, Filter Guy and myself plus others had numerous discussion about the wiring of these units that bond N-G under inverter power.

Define your needs first, what is the max draw, the usage of the inverter (home, RV, off grid, emergency power), the size of your PV array. Then search in the archives here, plenty of threads about all of these units and educate yourself on what each one is capable of. Don't be afraid to search other brands, there might be a feature or function that you might prefer, it's all about what needs and usage you define.
When I talk to signature solar they say there is no N-G bond under any circumstances with the growatt 3000TL lvm-es and that the N-G bond needs to be done at the breaker panel, I have talked to multiple electricians and they also agree that the inverter should not have a N-G bond and that it needs to be done at the panel, I have recieved so many different responses to what is or isn't true that I can't make heads or tails of any of it
 

Henderson

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Jan 9, 2022
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I have been looking at either two growatt 3000 one growatt 5000 or the mpp lv6548, I think I have settled on the growatt but im not positive, I like the option of two 3000 growatts because of the one is none two is one way of thinking plus I get 6000 watts and split phase and only needs 120 volts to get pass through and I would also get two PV inputs, the 5000 growatt has a bit easier of install but it needs the transformer to get 120 volts and I'm not sure how well that works and can't find any information about it needing 120 or 240V for pass through but I only getone PV input. The MPP lv6548 is also a very nice inverter but im still confused in if it has bonded neutral or not but again it needs 240V to be able to use the pass through option and I like the two PV inputs on it. I'm almost positive no one here has used all three of these but im looking for real life experiences with these.
For the LV6548s which seem quite nice, you'll only get 240V split phase by combining at least 2 of them in parallel.
 

Cyanlite

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Jun 13, 2021
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I was told that on the U.S version of the MPP lv6548 N-G bond screw is still in place but there is a relay that controls when the N-G bond occurs and that the N-G is needed to pass UL even thought it's not UL listed I know that manufacturers have different build designs but how could it work safely if two manufacturers say the way they built it is the correct way, this is one of the responses I got from MPP (not watts247)

"The way GFCI works exactly is that you will need to BOND N-G under inverter mode (you cannot leave it OPEN), such that it will convert what is normally a "float" output to a zero differential so that way your RCD doesn't trip. This is tested under UL and if you're saying this is a problem then clearly UL has a problem, otherwise how did they pass this?"
MPP LV6548 is indeed UL Listed.
 

Cyanlite

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Jun 13, 2021
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48
No, not quite. It is listed by TUVus to be UL1741 compliant. UL1741 is a standard about grid interaction.
Watts247 then has a problem. They're advertising it as UL Listed.

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