Safety hazard w/ Growatt 5000ES (European version) when connected to American grid

[Goboatingnow]

I am not qualified or smart enough to justify all of this hack work, I just read what far more intelligent and knowledgeable people than us have written on here in the past and take their advice to heart.
But the more that people try to argue this is a perfectly fine situation the more I realize it actually is not and I wonder what some people's motives are.
Ac voltage is a weird and wonderful thing that can really hurt us if we disrespect it, just like DC voltage.
I feel very fortunate to be able to learn from far clever people than me on here.
I worked for Kodak in main labs on three phase 400 volt machines with highly conductive liquids and I respected the living daylights out of that shit because one wrong move and I was very dead.

Could you point out where technically the problem lies then with the correct wiring of the inverter and auto transformer

 

[Goboatingnow]

Will P video rather labours the point. The only issue is the existence of an inappropriate earth bond in the inverter remove it and all is fine.

 

[Hedges]

Could you point out where technically the problem lies then with the correct wiring of the inverter and auto transformer

For the schematic provided, I pointed out that a short of utility L1 or L2 to inverter chassis makes the entire "ground" system 120V with respect to earth, a shock hazard.

If L1 or L2 out of the inverter up to the next breaker shorts to chassis, same thing.

Safety hazard w/ Growatt 5000ES (European version) when connected to American grid

That does not address the fact that the input is designed for one leg to be at or near ground potential. Basic Engineering 101

diysolarforum.com

Why do you think that is not a problem?

 

[Tecnodave]

If your home were to burn to the ground with a euro inverter or all in one which was not manufactured specifically for North American split phase grid you have just handed your Insurance provider a walk away card. In all Insurance agreements there are clauses that all such work be approved by the local AHJ (authority having jurisdiction) (code enforcement) AND up to code..AND permitted...... Some Insurance Inspectors are more critical than the building inspector and the fire inspector and will fight to extremes to avoid a payout.

 

[Pendrak]

Safety hazard w/ Growatt 5000ES (European version) when connected to American grid/INSURANCE too​

For the conclusion:

-First make sure there is no bounding of N-G on the European unit (the famous screws, get a US unit like the Growatt 5k ES US version from signature solar, etc).
-You want 120v and ongrid use a isolation transformer (is the only safe way to use it on USA and insurance approve this in USA right?)
-If you use it offgrid (without use the AC inputs) then all perfect, you can use autotransformers for 120v without any problem, insurance work in this option right?.
-Other option is use 2 units 120v to produce 240v, you don't need a transformer if you do this. (like the EG4 and MPPT units). Insurance approve this.
-For those who don't know why is soo important the Neutral-Ground bonding on the meter of your house is because of there is a component called

Ground Fault Circuit Breaker (GFCI)​

This guy cut the energy of your house if there is a ground fault, a ground fault occurs when a hot wire touches the ground wire and interacts with water or any sort of debris. In the event of a ground fault, the GFCI will immediately trip (rated with 5mA sensitivity) and is required by the NEC, so no NEC no insurance.

This CFCI breaker (or outlet) no work if you don't do the N-G bonding on the meter ( let the leakage of energy go back to the source, in other words go back to the transformer of the grid).

Here a detailed explanation:

Why bond the neutral and the ground wire in the main panel? - E&S Grounding Ask the Experts

Over Current Protection Devices (OCPD) such as circuit breakers and fuses actually require a short and intense INCREASE in electrical current (a short) in order to detect the fault and cut the circuit off.

esgrounding.com

Because in this forum came lot of people from all the world (like me), check your local regulations.

Someone correct me if i am wrong.

edit: i add more info i learn from this forum, everything i know about connectors, wire size, T class fuses, breakers (din rail and normal ones), lugs, JK BMS, DIY battery's, where to get LIFEPO4 cells and don't get screw, etc. came from here, so thanks all.

 

[Quattrohead]

Could you point out where technically the problem lies then with the correct wiring of the inverter and auto transformer

No I cannot I already told you I'm not qualified enough to do so.

 

[Quattrohead]

Safety hazard w/ Growatt 5000ES (European version) when connected to American grid/INSURANCE too​

For the conclusion:
You want 120v and ongrid use a isolation transformer (is the only safe way to use it on USA and insurance approve this in USA right?)
If you use it offgrid (without use the AC inputs) then all perfect, you can use autotransformers for 120v without any problem, insurance work in this option right?.

Someone correct me if i am wrong.

See someone has been listening to people better qualified than us. I believe you are correct, except I don't know about insurance that has been argued both ways.

 

[Goboatingnow]

No I cannot I already told you I'm not qualified enough to do so.

Then with regret you not pronounce so on the solution

 

[Goboatingnow]

For the schematic provided, I pointed out that a short of utility L1 or L2 to inverter chassis makes the entire "ground" system 120V with respect to earth, a shock hazard.

No the case of the invertor is grounded in the normal way.

If L1 or L2 out of the inverter up to the next breaker shorts to chassis, same thing.

No again the chassis can be grounded in the way.

Safety hazard w/ Growatt 5000ES (European version) when connected to American grid

That does not address the fact that the input is designed for one leg to be at or near ground potential. Basic Engineering 101

diysolarforum.com

Why do you think that is not a problem?

It’s not a problem once you don’t bond neutral and the earth on an invertor fed by US split phase

 

[Goboatingnow]

Safety hazard w/ Growatt 5000ES (European version) when connected to American grid/INSURANCE too​

For the conclusion:

-First make sure there is no bounding of N-G on the European unit (the famous screws, get a US unit like the Growatt 5k ES US version from signature solar, etc).
-You want 120v and ongrid use a isolation transformer (is the only safe way to use it on USA and insurance approve this in USA right?)
-If you use it offgrid (without use the AC inputs) then all perfect, you can use autotransformers for 120v without any problem, insurance work in this option right?.

There is nothing wrong with the auto transformer method of generating invertor derived split phase. There is NO need for isolating transformers.

-Other option is use 2 units 120v to produce 240v, you don't need a transformer if you do this. (like the EG4 and MPPT units). Insurance approve this.
-For those who don't know why is soo important the Neutral-Ground bonding on the meter of your house is because of there is a component called

Ground Fault Circuit Breaker (GFCI)​

A RCD device does not need a neutral earth bond to work

Neutral earth bonding at the meter is a more modern alternative to earth rod bonding. Historically on Europe earth neutral bonding at the customer premises didn’t exist. Many such systems remain to this day.

This guy cut the energy of your house if there is a ground fault, a ground fault occurs when a hot wire touches the ground wire and interacts with water or any sort of debris. In the event of a ground fault, the GFCI will immediately trip (rated with 5mA sensitivity) and is required by the NEC, so no NEC no insurance.

This is a US specific instance. It doesn’t need a specific neutral earth bond to work as a safety protector.

This CFCI breaker (or outlet) no work if you don't do the N-G bonding on the meter ( let the leakage of energy go back to the source, in other words go back to the transformer of the grid).

Nonsense and wrong

Here a detailed explanation:

Why bond the neutral and the ground wire in the main panel? - E&S Grounding Ask the Experts

Over Current Protection Devices (OCPD) such as circuit breakers and fuses actually require a short and intense INCREASE in electrical current (a short) in order to detect the fault and cut the circuit off.

esgrounding.com

Because in this forum came lot of people from all the world (like me), check your local regulations.

Someone correct me if i am wrong.

I have

edit: i add more info i learn from this forum, everything i know about connectors, wire size, T class fuses, breakers (din rail and normal ones), lugs, JK BMS, DIY battery's, where to get LIFEPO4 cells and don't get screw, etc. came from here, so thanks all.

 

[Goboatingnow]

This thread shows how so many people are confused about the role of protective earth and the action of residual current protection devices.

It makes me more and more concerned about DIY solar involving mains wiring given the clear technical mis understandings display here. People cannot separate “ code “. Custom & practice from electrical first principles

Don’t touch anything Mains related folks get a professional.

 

[Hedges]

This thread shows how so many people are confused about the role of protective earth and the action of residual current protection devices.

Confusion reigns.

Don’t touch anything Mains related folks get a professional.

I suggest you look in the mirror.


Note that while this auto-transformer has UL listing, that was not as part of a system with this inverter. Just stand-alone.
There is neither UL listing nor a licensed PE's stamp for the configuration shown.
(A design could be correct and safe without those, but this particular design I and others have found safety issues with.)


Consider again at the Inverter/Autotransformer schematic.
What happens if a fault from line to ground occurs at either of the two locations shown?
I say that chassis of inverter, and ever ground wire and component, is now driven to 120 Vrms relative to Earth.

You may have a ground rod driven where the ground symbol is shown. Service entrance also has one. There will be what, 25 ohms between those to ground rods? So 5A flows. The Earth near your ground rod is raise to 125Vrms, but elsewhere is lower.
If you touch anything grounded to your system, and you touch anything else grounded like a water pipe or gas stove, you get a shock.

Why do you think this use of an autotransformer is OK?

 

[Goboatingnow]

Confusion reigns.



I suggest you look in the mirror.


Note that while this auto-transformer has UL listing, that was not as part of a system with this inverter. Just stand-alone.
There is neither UL listing nor a licensed PE's stamp for the configuration shown.
(A design could be correct and safe without those, but this particular design I and others have found safety issues with.)

Rating agency approval and safety are of course not the same

Consider again at the Inverter/Autotransformer schematic.
What happens if a fault from line to ground occurs at either of the two locations shown?
I say that chassis of inverter, and ever ground wire and component, is now driven to 120 Vrms relative to Earth.

Firstly you understand this is a European derived circuit.

In such cases a whole house RCBO is fitted

You may have a ground rod driven where the ground symbol is shown. Service entrance also has one. There will be what, 25 ohms between those to ground rods? So 5A flows. The Earth near your ground rod is raise to 125Vrms, but elsewhere is lower.

No. In this case this is a European derived circuit , there is no consumer panel neutral earth bond , only a earth rod.

Secondly there will be a whole house RCBO 30mA trip

If you touch anything grounded to your system, and you touch anything else grounded like a water pipe or gas stove, you get a shock.

Why do you think this use of an autotransformer is OK?


View attachment 118442

Firstly in Europe ground loop impedance must be around 0.8 ohms or it’s not acceptable

Hence the ground circuit will not be raised. By anything like you say , and the short circuit /over load breakers will be tripped

Again for complete protection in this circuit I would add RCBO on the invertor input and output.

NOTE

this circuit illustrated by “ hedges “ is a European floating neutral example

In a US version the case ground of the invertor ( and not L2/ neutral ) would always be grounded in the normal fashion

Hence any live fault to case ground would trip the distribution panel breakers or the output overload protection breakers.

Hence it would be completely safe

 

[Pendrak]

Confusion reigns.



I suggest you look in the mirror.


Note that while this auto-transformer has UL listing, that was not as part of a system with this inverter. Just stand-alone.
There is neither UL listing nor a licensed PE's stamp for the configuration shown.
(A design could be correct and safe without those, but this particular design I and others have found safety issues with.)


Consider again at the Inverter/Autotransformer schematic.
What happens if a fault from line to ground occurs at either of the two locations shown?
I say that chassis of inverter, and ever ground wire and component, is now driven to 120 Vrms relative to Earth.

You may have a ground rod driven where the ground symbol is shown. Service entrance also has one. There will be what, 25 ohms between those to ground rods? So 5A flows. The Earth near your ground rod is raise to 125Vrms, but elsewhere is lower.
If you touch anything grounded to your system, and you touch anything else grounded like a water pipe or gas stove, you get a shock.

Why do you think this use of an autotransformer is OK?


View attachment 118442

In my case if this happen is not a problem, the first I do if something no work is disconnect the mains and troubleshoot with a voltmeter, but I see a big problem with the insurance company, they cant approve on USA this diagram, the Ground Fault Circuit Breaker cant work because cant detect the fault if the energy don't have a way back to the source (neutral-ground bond).

 

[Quattrohead]

Then with regret you not pronounce so on the solutions

Then with regret you not pronounce so on the solution

We can agree to disagree then, you do your thing and I'll do mine.

 

[Goboatingnow]

soo all the problem is the chasis of the inverter, and the inverter can work with 120v on the gnd??? that cant fry the equipment?

There’s no issue with the chassis as it’s connected to ground in the normal way. The failure mode being advanced is hypothetical and easily countered with RCBO style safety devices.

 

[Quattrohead]

Don’t touch anything Mains related folks get a professional.

I suggest you look in the mirror.

Mr go boating I would leave it alone now if I were you LOL

 

[Goboatingnow]

We can agree to disagree then, you do your thing and I'll do mine.

No. I’m a professional EE. Hence I can feel competent to review the technical argument and make a conclusion

You’ve ( reasonably ) admitted you don’t have that expertise , yet you are pronounced it unsafe etc. how can you do that with any degree of competence.

Surely in that case the answer is merely to say “ I don’t know “ and can’t offer an opinion.

That’s why I challenged you. It’s one think you honestly admit your limitations. It’s entirely another to reach and state conclusions based on those limitations

 

[Pendrak]

There is no RCBO style safety devices on my country, i guess no one update the standards and we are working with old standards (or without then lol).

 

[Goboatingnow]

I suggest you look in the mirror.

Mr go boating I would leave it alone now if I were you LOL

I understand mains I have wired countless mains projects over 35 years of EE design and also wired three houses , one in the US.

I quite happy that I understand the technicals , hence I’m happy to derive technical conclusions.

I’m also happy to debate and defend my conclusions technically. But not people without justification telling me I’m wrong