Growatt MIN10000TL-XH-US Backup Connection

[Ryan Rowlett]

Hello! Glad to officially be here after lurking for so long. I have always had an interest in solar power and after getting a good deal on a bunch of panels, started pulling the trigger on some equipment to get power from them and start using it to power my home. One of which was a Growatt 10kw grid-tied inverter, which I unfortunately learned would not be compatible with a 48VDC battery bank I had built (should have gone with a hybrid inverter and done more research). Rather than return it and get something else, I decided to try an AC Coupling system instead.

Basically, I have an Ampinvt 5000W 48VDC to 120/240VAC that I have for my battery bank and it will be powering a subpanel that will supply power to a majority of my household loads. Since it shouldn't connect to the grid in the same manner as the Growatt unit to prevent backfeeding, could I use these backup connection terminals to supply power to the subpanel and AC Charging Port of the 5KW Ampinvt? The battery bank inverter can match the frequency of the Growatt output from what I've read. There isn't much literature for what these backup connections do besides go to an ATS, but if it's an always on-output, could we use that to power our subpanel?

Thank you in advance, I'll be posting more pictures of my current setup in the next few days!

 

[MajicDiver]

Hello! Glad to officially be here after lurking for so long. I have always had an interest in solar power and after getting a good deal on a bunch of panels, started pulling the trigger on some equipment to get power from them and start using it to power my home. One of which was a Growatt 10kw grid-tied inverter, which I unfortunately learned would not be compatible with a 48VDC battery bank I had built (should have gone with a hybrid inverter and done more research). Rather than return it and get something else, I decided to try an AC Coupling system instead.

Basically, I have an Ampinvt 5000W 48VDC to 120/240VAC that I have for my battery bank and it will be powering a subpanel that will supply power to a majority of my household loads. Since it shouldn't connect to the grid in the same manner as the Growatt unit to prevent backfeeding, could I use these backup connection terminals to supply power to the subpanel and AC Charging Port of the 5KW Ampinvt? The battery bank inverter can match the frequency of the Growatt output from what I've read. There isn't much literature for what these backup connections do besides go to an ATS, but if it's an always on-output, could we use that to power our subpanel?

Thank you in advance, I'll be posting more pictures of my current setup in the next few days!

It appears you have either a V1 or V2 MIN-US, it doesn’t matter for your question but I’m curious where you purchased it and which it is?

On a V1 or V2 the backup output functions as follows:
1. It is 240 vac only. To get 120 (a nuetral) you would need an auto transformer, or the Growatt “ATS” which is an ATS and autotransformer in the same enclosure. Or separate ATS with separate autotransformer.
2. The V1/V2 backup output is “hot” almost always. When the grid output is synced and connected to a grid it’s hot. It stays hot when the grid is lost. When the grid comes back the inverter has to sync its grid output to the grid and shut its internal breaker, the instant the inverter sees the the grid come back up, the backup output goes dead, and the instant the grid output syncs and connects to grid the backup output goes hot again. The manuals do not discuss this but I’ve observed and tested it. It’s how it must work of things to work properly with the Growatt ATS. FYI, I don’t use an ATS though. We are off grid full time, if we needed to go back gridtied I would switch with breakers. Read my profile system description for some details.
3. Yes, you could connect a subpanel to the backup output, most people would call that a critical loads panel. That’s what I was doing until system got big enough to go off grid permanently. Anything that uses 60hz can be connected to the subpanel. Make Sure if you don’t use a subpanel to put a breaker between whatever device you are connecting and the inverter backup output

 

[MajicDiver]

And by the way, you have one, you can test and see for yourself what I describe, if you notice a difference, let’s talk. I’ve been concerned about firmware revisions because I like how it currently works, software people tend to change stuff on a whim to suit themselves, so I’ve tested that and other stuff every firmware upgrade.

 

[MajicDiver]

Basically, I have an Ampinvt 5000W 48VDC to 120/240VAC that I have for my battery bank

It appears to me this is an OFF Grid inverter, you can’t connect it to the off grid output of any other inverter just as you can’t connect it to the grid.

 

[MajicDiver]

“AC Charging Port of the 5KW Ampinvt? ”
You should provide some documentation that shows what you are talking about here

 

[Ryan Rowlett]

It appears you have either a V1 or V2 MIN-US, it doesn’t matter for your question but I’m curious where you purchased it and which it is?

On a V1 or V2 the backup output functions as follows:
1. It is 240 vac only. To get 120 (a nuetral) you would need an auto transformer, or the Growatt “ATS” which is an ATS and autotransformer in the same enclosure. Or separate ATS with separate autotransformer.
2. The V1/V2 backup output is “hot” almost always. When the grid output is synced and connected to a grid it’s hot. It stays hot when the grid is lost. When the grid comes back the inverter has to sync its grid output to the grid and shut its internal breaker, the instant the inverter sees the the grid come back up, the backup output goes dead, and the instant the grid output syncs and connects to grid the backup output goes hot again. The manuals do not discuss this but I’ve observed and tested it. It’s how it must work of things to work properly with the Growatt ATS. FYI, I don’t use an ATS though. We are off grid full time, if we needed to go back gridtied I would switch with breakers. Read my profile system description for some details.
3. Yes, you could connect a subpanel to the backup output, most people would call that a critical loads panel. That’s what I was doing until system got big enough to go off grid permanently. Anything that uses 60hz can be connected to the subpanel. Make Sure if you don’t use a subpanel to put a breaker between whatever device you are connecting and the inverter backup output

Signature Solar, and I had purchased it only a few weeks ago (August 3rd, to be exact). I'll pull the PN for it later today. I had seen your gripes with them previously as well, and if I had known better, would have gone with a different distributor. I also was able to find the proper manual it needed thanks to your previous posts and threads - Thank you!

1. Fascinating! That would mean in order to have it power a critical loads panel for 120V, I would need an auto-transformer to provide a neutral as well, as you stated. I may look into this in the future to upgrade the system I have currently. A random thought - If I only needed 240VAC and a ground (let's say a 30A Clothes Dryer), would the back-up terminals be able to provide useable power in that sense?

2. This is exactly what I needed, a perfect answer! I planned on running some tests this week with it on a mini-grid since I'm waiting for POCO approval to grid-tie but this answers all of what I'll need. I originally planned to do something similar but will look deeper into your description today and take applicable notes for my situation.

3. Awesome! I will document my current set up and future plans soon. As my AMPINVT Inverter only requires 240VAC for AC Charging, I'll very likely use the backup terminals on the Growatt to charge my battery bank and then have my AMPINVT supply power to the critical loads panel. Basically, I'll have the Growatt as the PV and grid-tied mule, for lack of a better term, while the 5000W AMPINVT powers my household loads. While keeping bigger loads such as my AC, oven, and water heater at the main breaker panel to be used with the grid, the Growatt should be able to handle those loads and feed the grid according to my applicable guidelines here in Texas.

Thank you for your in-depth answer, Majic! You nailed every point I needed answered.

 

[MajicDiver]

If I only needed 240VAC and a ground (let's say a 30A Clothes Dryer), would the back-up terminals be able to provide useable power in that sense?

Maybe, most clothes - all I have seen - dryers have a neutral wire , no internal transformer for control power. If the appliance has a neutral wire you need to provide a functional neutral. But I’m a mechanical engineer and worked a career as a controls engineer, know enough about power systems to be dangerous so I would not rule out that someone who knows what they are doing could make it work without an auto transformer - I have no clue how though

 

[MajicDiver]

As my AMPINVT Inverter only requires 240VAC for AC Charging,

You need to look at my other comment post and make sure you correctly understand what that inverter actually is, you could potentially ruin both if it is what I suspect it is

 

[Solar Guppy]

That is a high voltage hybrid, the backup port needs a HV battery to do anything I believe:

Growatt APX Battery: 380V~550V/ Growatt ARO Battery :360V~550V/LG Battery:360V~450V

Here is the datasheet

 

[Ryan Rowlett]

“AC Charging Port of the 5KW Ampinvt? ”
You should provide some documentation that shows what you are talking about here

This here is the inverter unit I'm having run the critical loads subpanel.

5000W DC 48V Split Phase Pure Sine wave Inverter with AC Charger

NOTE: DIFFERENT TYPES OF LOADS HAVE DIFFERENT STARTING IMPULSE CURRENTS. CUSTOMERS NEED TO SELECT THE APPROPRIATE INVERTER MODEL ACCORDING TO THE ACTUAL EQUIPMENT POWER, CURRENT, AND LOAD CHARACTERISTICS. ATTENTION: This Power inverter is able to charge the battery bank when AC power is...

us.ampinvt.com

 

[Ryan Rowlett]

And by the way, you have one, you can test and see for yourself what I describe, if you notice a difference, let’s talk. I’ve been concerned about firmware revisions because I like how it currently works, software people tend to change stuff on a whim to suit themselves, so I’ve tested that and other stuff every firmware upgrade.

Here's my PN for the Growatt I have also. I'll run my own test also and verify if it does the same as you describe - On when Grid-On, On when Grid-Off, Off when Grid-Reconnect until frequency is stabilized, then back On.

 

[Ryan Rowlett]

That is a high voltage hybrid, the backup port needs a HV battery to do anything I believe:

Growatt APX Battery: 380V~550V/ Growatt ARO Battery :360V~550V/LG Battery:360V~450V

Here is the datasheet

Yes, from the Output Data (Backup) section, I see we're spitting out 240V at 65A which is a bit too much for my off-grid inverter.

What we'll likely do is have the Growatt grid-tied to the main breaker panel, have a 2P 30A breaker from the main breaker panel feed the AC Input for the hybrid/off-grid panel (since it'll be charged from the Growatt/PV Source), and have off-grid panel feed a critical loads panel. This way, the hybrid/off-grid never interacts with the grid and continues to supply power to the house in the event of a grid failure while never back feeding into it. A decent, textbook AC Coupled system, right?

 

[MajicDiver]

That is a high voltage hybrid, the backup port needs a HV battery to do anything I believe:

Growatt APX Battery: 380V~550V/ Growatt ARO Battery :360V~550V/LG Battery:360V~450V

Here is the datasheet

No, you are incorrect! the backup port works just fine wether gridtied or off grid with no battery exactly as I described. However, when off grid with no battery, it’s only power is from PV, but if there is sun there is power on the backup output,I’ve tested it. Of course you would not want to use it that way except for lights or something.
Edit: To be more accurate, I tested it on my V1’s, have not on my V2’s.

 

[Solar Guppy]

No, you are incorrect! the backup port works just fine wether gridtied or off grid with no battery exactly as I described. However, when off grid with no battery, it’s only power is from PV, but if there is sun there is power on the backup output,I’ve tested it. Of course you would not want to use it that way except for lights or something.

Good to know, thank you for the update!

 

[MajicDiver]

Here's my PN for the Growatt I have also. I'll run my own test also and verify if it does the same as you describe - On when Grid-On, On when Grid-Off, Off when Grid-Reconnect until frequency is stabilized, then back On.

That’s a part number for a V3 if I am not mistaken.

 

[MajicDiver]

Hello! Glad to officially be here after lurking for so long. I have always had an interest in solar power and after getting a good deal on a bunch of panels, started pulling the trigger on some equipment to get power from them and start using it to power my home. One of which was a Growatt 10kw grid-tied inverter, which I unfortunately learned would not be compatible with a 48VDC battery bank I had built (should have gone with a hybrid inverter and done more research). Rather than return it and get something else, I decided to try an AC Coupling system instead.

Basically, I have an Ampinvt 5000W 48VDC to 120/240VAC that I have for my battery bank and it will be powering a subpanel that will supply power to a majority of my household loads. Since it shouldn't connect to the grid in the same manner as the Growatt unit to prevent backfeeding, could I use these backup connection terminals to supply power to the subpanel and AC Charging Port of the 5KW Ampinvt? The battery bank inverter can match the frequency of the Growatt output from what I've read. There isn't much literature for what these backup connections do besides go to an ATS, but if it's an always on-output, could we use that to power our subpanel?

Thank you in advance, I'll be posting more pictures of my current setup in the next few days!

I was mistaken earlier today, that is a V3 inverter, note the “N/C” on the terminal lables under the backup connection- no connection.
All of my discussion above was regarding the V2 and V1, and is irrelevant for the V3. In this case, Signature Solar sold you exactly what they say they are selling.

 

[MajicDiver]

Good to know, thank you for the update!

I edited my post, I tested on my V1’s, never did on my V2’s - now I’m curious and will test one of them.

 

[Ryan Rowlett]

I was mistaken earlier today, that is a V3 inverter, note the “N/C” on the terminal lables under the backup connection- no connection.
All of my discussion above was regarding the V2 and V1, and is irrelevant for the V3. In this case, Signature Solar sold you exactly what they say they are selling.

Gotcha! I see what you're talking about, so we'll ignore those terminals for my set up.

Thanks again!

 

[MajicDiver]

No, you are incorrect! the backup port works just fine wether gridtied or off grid with no battery exactly as I described. However, when off grid with no battery, it’s only power is from PV, but if there is sun there is power on the backup output,I’ve tested it. Of course you would not want to use it that way except for lights or something.
Edit: To be more accurate, I tested it on my V1’s, have not on my V2’s.

I tested one of my V2 inverters today. I was disappointed to discover that with battery communication disconnected and battery breakers open, the backup output is only hot if the inverter is tied to grid. That is not what my original V1’s did, which are back in their boxes for spares. I tested my V1’s before I had batteries- and thus the inverters did not have the battery firmware installed- that’s probably the difference, if I figured out how to remove the battery firmware from them the backup output would probably function like the V1’s did before batteries installed. But, no point in trying to test that because not much use in a backup output without battery.

 

[jlmorrow]

can any of you tell me which Growatt Min 11400TL-XH-US P/N Pv01.0105200. V1 V2 or V3. I've search but could not find. Any help would be greatly appreciated

 

[MajicDiver]

can any of you tell me which Growatt Min 11400TL-XH-US P/N Pv01.0105200. V1 V2 or V3. I've search but could not find. Any help would be greatly appreciated

No clue what the question is? And context is important

 

[jlmorrow]

I am looking to purchase this model and was wondering which Version of the Min11400TL-XH-US, looking for a V2, Need to verify before I purchase. The part number doesn't look like a V3 or V2. Maybe a version1

 

[MajicDiver]

No clue what the question is? And context is important

Sorry, I see now. I posted a 2023 list several times, but that part number is not on it. I suggest asking Growatt or Self2Solar or Renvu - anything Sig Solar tells you I would ignore…

 

[jlmorrow]

Thanks, I haven't bought much from signature solar, but I have bought from Renvu, my V1 Min Inverter and you are so right about the 3 version and their purpose as to how you will need to install them. I've had my share of headaches from the beginning with Renvu, but I've had a better experience with Self to Solar.