Safe Grid Use of the 5000ES and transformer

[SignatureSolarJames]

 

[hipringles]

View attachment 80255

shouldn't this diagram show a n/g wire going from the utility to the AC IN panel? Or are you saying to remove the main panel's connection to utility N/G?
growatts should be on 30A breakers on the AC out panel (or more if you include the surge overhead)
transformer should be on a larger breaker too?

 

[SignatureSolarJames]

shouldn't this diagram show a n/g wire going from the utility to the AC IN panel? Or are you saying to remove the main panel's connection to utility N/G?
growatts should be on 30A breakers on the AC out panel (or more if you include the surge overhead)
transformer should be on a larger breaker too?

transformer is rated at 25A (x240 = over 5000w), the growatts can be anything under 40A

If you have only 1 inverter and want to risk not doing a bypass switch you can skip the AC In panel and just land on the AC in lugs of the inverter, Utilizing the off-grid ground as shown in the diagram though

 

[hipringles]

transformer is rated at 25A (x240 = over 5000w), the growatts can be anything under 40A

if you have only 1 inverter you can skip the AC In panel and just land on the AC in lugs of the inverter, Utilizing the off-grid ground as shown in the diagram tho)

To clarify since I edit'd my question:

Your saying to disconnect the main from the utility n/g?

MAYBE its just me, but I think your going to loose a lot of people if you answer this with a "yes". Not everyone wants a 240v only main panel, and all 120v loads on a critical loads

 

[Quattrohead]

That diagram is so stupidly wrong. Where the fuck are all the neutrals ???
Just coz they don't suite you does not mean you can make them go away.

 

[Quattrohead]

Please familiarize yourself with dedicated grounds, they are used in many other aspects of solar installs. If you are an off grid user you are installing your own ground rod anyway. I'm sorry you've worked yourself up here but it is a $16 part and lowe's/ every other hardware store carry bundles on hand.

You're just plain wrong here sir.

Different discussion. And I bet you my right nut most end users will never install a ground rod. They will connect stuff up and the light bulb glows....job done.

 

[Trip.Diamond]

Hello, we have reviewed Ian's video and discussed our approach with him, we both are growatt distributors and we both agree on how to safely setup connection to the grid should you choose to do so. Ian just went ahead with the warnings first here Vs. the solution. We wanted to start a thread discussing a completely safe way to operate the 5000ES and transformer.

Issue #1: neutral-ground bonding, we have had these units ship without the neutral to ground bond since we started carrying them in order to avoid issue 1 entirely, Ian is aware, and we agreed the real exposure here is the people buying direct from China with no thought to modification.
OEM modification specifically for the American market, they even designed the auto transformer for it to go with.

Issue #2 Neutral conflict between grid and off grid autotransformer. we are loading a schematic on this one: THERE SHOULD NEVER BE A NEUTRAL PASSED THROUGH FROM THE GRID. this is true for the split phase 12kW and 6kw inverters as well. the bottom line here is that all that is needed from the grid input is L1/L2. a dedicated ground rod is needed to bond to neutral of the off-grid autotransformer as well.

As far as autotransformer size is concerned let's take a second and discuss what the ratings mean. the "imbalance power is reflective of the balance between the total 120v loaded L1 and L2 legs, NOT the total kW of 120v loads, 2x 5000es + 1 transformer with 5000w on L1 and 5000w on L2 has a transformer load of 0 watts, 5000 on L1 and 4000w on L2 is a load of 1000W on the transformer.
-A 5000es + 1 transformer with 3kw of imbalance can run a max power split of 4kw/1kw on L1/L2 4
-2x5000es + 1 transformer can split max at 3.5kw/6.5
This beats the imbalance tolerance of sol-ark, MPP, Growatt LF and most others.
-Any 240v loads like an air conditioner, heater or pump pull evenly and therefore reduce the potential for imbalance.

You can't run an unlimited amount with 1 transformer and per the manufacturer you need breaker protection, but if you are building large system, odds are you have a lot of 240v loads that by nature will never touch the transformer at all. the inverter will trip pretty rapidly after, but your devices are partially exposed, however we have never seen an issue from people who put max 2 inverters per transformer.

View attachment 80254

This method of creating a 'separately derived system' is a completely acceptable way to go and should work best for most people!

It will require a separate grounding rod be placed not less than 8 feet from any existing ground rod. I would also use Shunt trip breakers for the output of the Growatts tied to the Transformer breaker. For added safety.

However I see a problem with the way you drew it in your schematic. You have a Ground line running from the Main Panel to the Sub Panel and then Bond it in the Sub Panel. This will create a Bond in two places as the Main Panel for Utility disconnect will already have a Neutral/Ground Bond in place.


If you remove the wire coming from the Main Ground you should be good.

 

[Solar Guy Richard]

Hey all writing this from my phone so excuse me if I misspell anything or get autocorrected. I’d like to make some clarifying statements here just as an observation.

We are taking an off grid, European inverter and configuring it for use with an American system using a grid tied AC support. That being said - our goal is to provide a safe and operational system. If you are upset that you need to drive a grounding rod - this is not the best option for you. If you are upset that you need to do some additional wiring for safety and operational purposes - this is not the best system for you.

However, if you are a DIYer who is looking for a highly efficient, inexpensive system, we are here to support you as much as we can and make sure you stay safe while doing it.

There are over 5,000 devices out there currently operating using this design without issues. Of course there are going to be people who disregard our advice and suggestions and operate their system dangerously - there is no foolproof way for us to prevent this. I’m happy to find answers for any additional concerns. We are also going to be publishing a few more diagrams with different set ups for everyone to look at. Feel free to PM me with questions and any feedback, I’m already taking what is written here and implementing it into our data for publishing.

Again, I want to thank this great community and want you all to know we are here to help you and grow the solar industry.

 

[svsagres]

Driving an 8' ground rod is no big deal, a normal part of some electrical work.

the issue is that in a grid situation, that grounding rod isn’t actually the only connection to earth. Because it is bonded to the neutral conductor at the service panel, it’s also bonded to the shared neutral with all your neighbors, the pole (or pad mount grounding conductor) and pretty much everything else leading up to the point where you hit a delta feed. This leads to a nice low impedance connection to earth, but your own connection is only a small contribution to it.

 

[SignatureSolarJames]

This method of creating a 'separately derived system' is a completely acceptable way to go and should work best for most people!

It will require a separate grounding rod be placed not less than 8 feet from any existing ground rod. I would also use Shunt trip breakers for the output of the Growatts tied to the Transformer breaker. For added safety.

However I see a problem with the way you drew it in your schematic. You have a Ground line running from the Main Panel to the Sub Panel and then Bond it in the Sub Panel. This will create a Bond in two places as the Main Panel for Utility disconnect will already have a Neutral/Ground Bond in place.
View attachment 80282

If you remove the wire coming from the Main Ground you should be good.

I see no connection between the ground in the meter and the panel you circled...

 

[Solar Guy Richard]

This method of creating a 'separately derived system' is a completely acceptable way to go and should work best for most people!

It will require a separate grounding rod be placed not less than 8 feet from any existing ground rod. I would also use Shunt trip breakers for the output of the Growatts tied to the Transformer breaker. For added safety.

However I see a problem with the way you drew it in your schematic. You have a Ground line running from the Main Panel to the Sub Panel and then Bond it in the Sub Panel. This will create a Bond in two places as the Main Panel for Utility disconnect will already have a Neutral/Ground Bond in place.
View attachment 80282

If you remove the wire coming from the Main Ground you should be good.

The utility ground is kept separate from the system. Shouldn’t have any interference.

 

[SignatureSolarJames]

To clarify since I edit'd my question:

Your saying to disconnect the main from the utility n/g?

MAYBE its just me, but I think your going to loose a lot of people if you answer this with a "yes". Not everyone wants a 240v only main panel, and all 120v loads on a critical loads

No disconnecting here, if you are leaving your main panel in just don't pull the neutral or ground off

 

[Quattrohead]

We are taking an off grid, European inverter and configuring it for use with an American system using a grid tied AC support.

Why does it have AC input connectors and show a possible grid connection in the manual if it is an off grid unit ???

 

[SignatureSolarJames]

Why does it have AC input connectors and show a possible grid connection in the manual if it is an off grid unit ???

off grid meaning non-selling.

 

[Trip.Diamond]

Hey all writing this from my phone so excuse me if I misspell anything or get autocorrected. I’d like to make some clarifying statements here just as an observation.

We are taking an off grid, European inverter and configuring it for use with an American system using a grid tied AC support. That being said - our goal is to provide a safe and operational system. If you are upset that you need to drive a grounding rod - this is not the best option for you. If you are upset that you need to do some additional wiring for safety and operational purposes - this is not the best system for you.

However, if you are a DIYer who is looking for a highly efficient, inexpensive system, we are here to support you as much as we can and make sure you stay safe while doing it.

There are over 5,000 devices out there currently operating using this design without issues. Of course there are going to be people who disregard our advice and suggestions and operate their system dangerously - there is no foolproof way for us to prevent this. I’m happy to find answers for any additional concerns. We are also going to be publishing a few more diagrams with different set ups for everyone to look at. Feel free to PM me with questions and any feedback, I’m already taking what is written here and implementing it into our data for publishing.

Again, I want to thank this great community and want you all to know we are here to help you and grow the solar industry.

My apologies! I did not mean to offend anyone. For the record I own the same system shown in the schematic. I have two Growatt spf 5000 ES and a solaredge Autotransformer. I have been running them for almost a year now and love them!

I do believe the way the schematic shows a ground line running from the Main Panel to the Sub Panel is wrong. There will be a N/G bond either at a Main Disconnect between the Meter and the Main Panel or it will be in the Main Panel (depending on where you live). This is NEC Code in all of North America. If you run a ground line from the Main Panel to the Sub Panel you no longer have a 'separately derived system'. Every thing else in the schematic looks perfect!

 

[Bud Martin]

Has anyone confirmed yet on the Growatt 5k (by taking the board all the way out to see the stand-off underneath), and confirm if removal of the bonding screw is sufficient means of separating the bond? Or like is it a millimeter away from touching (like a light press on the board will make it connect again)? It seems to me if I was removing the bond, I would take the board all the way out for a minute and take off the standoff underneath it to confirm a safer separation distance.

Is this an issue? Pictures?

If they can put the screw back in then the standoff was not removed which is bad way of doing it, they need to either remove the standoff or put insulator material under the PCB that can handle the Voltage, I doubt that they actually remove the standoff.

 

[Zwy]

View attachment 80255

You need to watch this:

 

[Cheap 4-life]

No disconnecting here, if you are leaving your main panel in ten just don't pull the neutral or ground off

Most people are using the inverters AC in as a grid feed in to charge the batteries if needed. For most the main panel (AC in as you call it) will stay operational. That means neutral/ground (however you look at it) needs to come from the meter to the main panel and are already bonded together either in the meter or before the weather head.

So are you saying to not connect neutral or ground from the main panel to the growatts? The diagram shows ground from main panel to the growatts.
The diagram suggests that the ground/neutral that comes from the meter should be removed from the main panel. Therefore making the main panel 240v only. Also suggests removing all of the homes loads from the main panel and relocate them to the load panel. And install an additional ground rod that is now the only ground rod the home and inverters are using. Am I looking at the diagram properly?

 

[Hedges]

View attachment 80255

As shown, if a fault develops in a GroWatt (or AC In panel, or AC Out panel, or Load panel),
and "L1" shorts to chassis, chassis of all those devices goes to 120VAC.
The only path back to utility meter is through the earth. Your added ground rod is at 120VAC, ground rod by utility meter is zero volts. Current flows, but not enough to trip a breaker feeding GroWatt (Faults downstream of GroWatt might trip a breaker or shut off GroWatt, but faults through AC Input of GroWatt will not.

The earthworms will frantically wriggle to the surface.

I believe this is wrong. A ground wire from utility meter providing continuity to case of GroWatt case is required, so fault causes breaker to clear.

 

[Bud Martin]

As shown, if a fault develops in a GroWatt (or AC In panel, or AC Out panel, or Load panel),
and "L1" shorts to chassis, chassis of all those devices goes to 120VAC.
The only path back to utility meter is through the earth. Your added ground rod is at 120VAC, ground rod by utility meter is zero volts. Current flows, but not enough to trip a breaker feeding GroWatt (Faults downstream of GroWatt might trip a breaker or shut off GroWatt, but faults through AC Input of GroWatt will not.

The earthworms will frantically wriggle to the surface.

I believe this is wrong. A ground wire from utility meter providing continuity to case of GroWatt case is required, so fault causes breaker to clear.

Yep.