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Growatt 48v 3000 Open Neutral

I don't know how to draw schematics, but my system is as simple as it can be. Shore power goes to Growatt and power from pure sine inverter goes to Growatt. Those lines are connected in automatic transfer switch: Inverter is connected to Growatt all the time, unless shore power is on. When I connect shore power outlet, switch cuts off power from inverter and connects shore power to Growatt. PV goes to PV inlets in Growatt and batteries are connected to battery outputs in Growatt. From Growatt line goes to circuit breaker box.

View attachment 72490




Yes, I do have SPF 3000TL LVM. I was looking for option 24 when Growatt was off, but no cigars. I've found option 23, but there is no 24.

View attachment 72491
There are two conversations on one thread. I need to go back and review this before I respond. It might be a while.
 
If I am correct about what is going on, then there is a problem with mobile set-ups because the system may or may not be on shore power.
If the You-tube video is correct and it is OK to connect Neutral-in and Neutral-out, then this may be a solution for a mobile set-up.

View attachment 72509
With this arrangement, if there is no shore power, the relay creates the N-G bond. When there is shore power the bond is broken and neutral is connected to shore power. Notice that there can never be a time when there is both a shore power bond and the local bond.

WARNING: I have not built and tested the above circuit....
@FilterGuy Mine is definitely not a mobile setup. Hardwire into reliance energy transfer switch that was diagramed before. I am also going to test no ac output ground or neutral as only the hot is changed in the reliance TS. That video of bonding at neutral in/out is super interesting for home hard wire and keeping the bond back at the main service panel. Lots to test on this.
 
When measured on the cables coming out of the GroWatt, I am getting
G/N 58V,
G/L 51V,
L/N 120V.
Do you get this when the inverter is in Line mode (Power from the input) or when in inverter mode (Power from Battery) or both?
When I turn on Blue Sea circuit breaker, it changes to:
G/N 151V,
G/L 148V and
L/N 120V.
Where in the circuit is the Blue Sea Circuit breaker? Is that in the '120V 'fuse' Box? Is it the 8027 AC Master Panel?
 
I don't know how to draw schematics, but my system is as simple as it can be. Shore power goes to Growatt and power from pure sine inverter goes to Growatt. Those lines are connected in automatic transfer switch: Inverter is connected to Growatt all the time, unless shore power is on. When I connect shore power outlet, switch cuts off power from inverter and connects shore power to Growatt. PV goes to PV inlets in Growatt and batteries are connected to battery outputs in Growatt. From Growatt line goes to circuit breaker box.

View attachment 72490




Yes, I do have SPF 3000TL LVM. I was looking for option 24 when Growatt was off, but no cigars. I've found option 23, but there is no 24.

View attachment 72491
Is this a proper representation of your system?

1637135944365.png

What is the make & model of the 12V Inverter?
 
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I don't have option 24 in my menu, and that makes connection you illustrated impossible?


I contacted Growatt about this

From: xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
Sent: Monday, November 15, 2021 11:06 PM
To: '美国' <usa@ginverter.com>; 'Marco Liu' <marco.liu@growatt.com>; 余志伟 <zhiwei.yu@growatt.com>
Cc: '刘庆存' <owen.liu@growatt.com>; service@ginverter.com
Subject: Re: 答复: 答复: Dry Contact specifications for the SPF 3000TL LVM


I have a customer that is saying they do not have option 24 on their SPF 3000TL LVM. Has something changed in the firmware or hardware?


Thank You

This is their reply

On Wednesday, November 17, 2021, 12:16:21 PM PST, Marco Liu <marco.liu@growatt.com> wrote:

Hi Paul,
Yes, the new firmware did the change by removing the setting 24: enable/disable the neutral and grounding of AC output combination.

Thanks & Best Regard,

Marco Liu

The answer explains why it is no longer being seen, but does not say what the replacement is so I replied with this:
On Wednesday, November 17, 2021, 12:19:39 PM PST, Paul xxxxxxx <xxxxxxxxxxx.com> wrote:

Is the function always enabled? If not, how should the user enable it?
 
@FilterGuy
Finally got around to testing. Growatt SPF3000 is on my rolling cart with 48v pack on shelf below...all in the name of testing! I did not test with my Reliance Transfer switch just yet, but input was on same GFCI outlet. This is MUCH better then previous metrics a few pages back

Ok, so I took the risk based on the previous video and jumped the neutrals between input and output. Interesting results below:
Utility 12a Load
  1. Amps on G: 0.01a
  2. N/G: 4.6v (measured same on input)
  3. L/G: 119v
  4. L/N: 115v
Battery 12a Load: (did not unplug GW, just changed to SBU)
  1. Amps on G: 0.02a
  2. N/G: 0.026v (measured same on input)
  3. L/G: 120v
  4. L/N: 120v
 
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@FilterGuy
Finally got around to testing. Growatt SPF3000 is on my rolling cart with 48v pack on shelf below...all in the name of testing! I did not test with my Reliance Transfer switch just yet, but input was on same GFCI outlet. This is MUCH better then previous metrics a few pages back

Ok, so I took the risk based on the previous video and jumped the neutrals between input and output. Interesting results below:
Utility 12a Load
  1. Amps on G: 0.01a
  2. N/G: 4.6v (measured same on input)
  3. L/G: 119v
  4. L/N: 115v
Battery 12a Load: (did not unplug GW, just changed to SBU)
  1. Amps on G: 0.02a
  2. N/G: 0.026v (measured same on input)
  3. L/G: 120v
  4. L/N: 120v
It looks like you have a solution.

BTW: The 4.6V when powered from grid is not unusual but is a little higher than I would expect for something hardwired in. It is the voltage drop due to the current on the neutral line. Check all of the connections between the inverter and your main breaker box.
 
Well...... things get more and more 'interesting'.

As reported in an earlier post, Growatt said Program 24 is not in the latest firmware so I sent them this question:
On Wednesday, November 17, 2021, 12:19:39 PM PST, Paul xxxxxxx <xxxxxxxxxxx.com> wrote:

Is the function always enabled? If not, how should the user enable it?

I just got this response:
On Monday, November 22, 2021, 03:58:01 PM PST, Marco Liu <marco.liu@growatt.com> wrote:

Default of the setting 24 is disable. It’s not available now to enable it.

Thanks & Best Regard,

Marco Liu

That is not very helpful so I replied with this:
Marco,
Thank you for that information. Does Growatt have a recommendation for how to handle the Neutral-Ground bond that is required in the US?

Some people on the web report that it works to hook the input and output Neutral together as shown below.... Does Growatt support this?

1637628575164.png
Thank You

Paul
I will let everyone know what I hear back.
 
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Well...... things get more and more 'interesting'.

As reported in an earlier post, Growatt said Program 24 is not in the latest firmware so I sent them this question:


I just got this response:


That is not very helpful so I replied with this:

I will let everyone know what I hear back.
Thanks for following up with them. Looking forward to their response...if they provide an actual response.
 
OK Folks, I finally got some usefull information from Growatt:

Marco Liu <marco.liu@growatt.com>
To:'Paul
Cc:'刘庆存',service@ginverter.com,'余志伟','美国'

Wed, Nov 24 at 3:09 PM
Hi Paul,

We have two newer N-G version of SPF 3000TL LVM that came with Neutral and Ground interconnection and no need to do any extra wiring or setting. The customer can checks the nameplate to verify these specific N-G version.

Model Number was listed in the following
  • SPF 3000 TL LVM-24P – model# SKSL00.0010200
  • SPF 3000 TL LVM-48P – model# SKSL00.0010000

Other SPF 3000TL LVM-24P or -48P models without the setting 24 available, please connect manually the Neutral wire between inverter AC input and AC output like the diagram you provided in the previous email.
1637797390369.png

Thanks & Happy Holiday,

Marco Liu
 
Thank you all for this thread! I was in the same situation in trying to figure out proper grounding for the same growatt (older model, it turns out). The email from the growatt person convinced me to try the jumper and that seems to be the solution indeed. I wish they would document this in the manual!

Is there anything else to be concerned about - is there a recommendation for grounding the chassis of the growatt? What about the battery bank (the EG4's have a ground screw on the front it looks like)?
 
I wish they would document this in the manual!
I hope GroWatt will put this kind of important info on their website and in the user manual.
I hear you guys!!!! I think it is boarding on criminal negligence that they don't document this stuff. Growatt is horrible about it. The MPP documentation is just as bad, but their support team seems to be a little more responsive to questions.
 
is there a recommendation for grounding the chassis of the growatt?
The AC-In Ground, AC-out Ground and case of the growatt are all tied together internally. As long as the AC is properly grounded, the case is properly grounded. Adding an additional ground to the case will just create a ground loop.
 
@FilterGuy You sir are an officer and a gentleman. A huge thanks for everything you do for this community. I've spent the best part of 2 days trying to find an answer to the question of bonding the ground and neutral on a Growatt. You the only person who gave a detailed and a clear answer. You even went the extra mile to contact Growatt. What a guy.
 
Sorry for hijacking this older thread and this may not be the best place: I am looking at the Growatt (SPF 3000TL LVM-US 120V) and have a Reliance Transfer Switch. It seems I will be facing the same issues with the N-G bond as others in the thread. Is there a better option?

Currently looking at drawing from the grid to keep the batteries topped up (seems the N-G is not an issue here, as long as I don't use the inverter to power anything).

Then use the inverter to power some critical circuits using the TS (neutral and ground are connected to the main panel): this is where the issue seems to be if my reading of this thread is correctly?
 
Sorry for hijacking this older thread and this may not be the best place: I am looking at the Growatt (SPF 3000TL LVM-US 120V) and have a Reliance Transfer Switch. It seems I will be facing the same issues with the N-G bond as others in the thread. Is there a better option?

Currently looking at drawing from the grid to keep the batteries topped up (seems the N-G is not an issue here, as long as I don't use the inverter to power anything).

Then use the inverter to power some critical circuits using the TS (neutral and ground are connected to the main panel): this is where the issue seems to be if my reading of this thread is correctly?
There should only be one N/G bond at any given time.
Whatever it takes to make this happen.
 
There should only be one N/G bond at any given time.
Whatever it takes to make this happen.
Fully understand that. From what I read, it seems to occur when AC out is used because it would then be at the inverter as well as the main panel.

Sounds like there is a reasonable solution (which would meet code in Ontario, Canada?) or using a different inverter that doesn't need a workaround.
 
Fully understand that. From what I read, it seems to occur when AC out is used because it would then be at the inverter as well as the main panel.

Sounds like there is a reasonable solution (which would meet code in Ontario, Canada?) or using a different inverter that doesn't need a workaround.
Does your inverter bond N/G all of the time?
Or only when running from the batteries?
 
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