diy solar

diy solar

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

I’ll be watching this thread with interest. At present I’m planning on a parallel Growatt setup for 240v loads only. Would be a shame not to be able to use 120v in the future. Also, the Growatt’s debatable UL compliant, certified or listed rating could also write my whole project off.
 
Once the fire dept traces the fire source back to the inverter your insurance company has a free get out of payment Pass.
I have seen discussions going both ways on this, but do what one feels comfortable with.
For my fun/experiments etc I am OK lashing some stuff up, but when I go off grid in my new build house everything (that I install for COO) will have to be UL. After that the fun begins again ;)
 
I’ll be watching this thread with interest. At present I’m planning on a parallel Growatt setup for 240v loads only. Would be a shame not to be able to use 120v in the future. Also, the Growatt’s debatable UL compliant, certified or listed rating could also write my whole project off.

With no grid input, possibly generator input of (grounded) neutral and 240V hot,
isolation transformer taking in single phase 240V from inverter and producing 120/240V split phase with grounded center tap,
should be OK for your application (except for the listing issue.)

Stand-alone use for loads wired single-phase 240V also OK.

If input is fed with an isolation transformer, it could be made to work safely with split-phase input from either grid or generator (or 120V generator.)
 
I’ll be watching this thread with interest. At present I’m planning on a parallel Growatt setup for 240v loads only. Would be a shame not to be able to use 120v in the future. Also, the Growatt’s debatable UL compliant, certified or listed rating could also write my whole project off.
I went to the Growatt US site for the SPF 5000 ES and it doesn't list a UL certificate. It only lists EU certifications.

I then did a search for 'growatt' on the UL database. The only thing I found is a rapid shutdown system that was tested with some growatt inverters. I found no UL listed Growatt inverters. (Maybe I need to search on different terms?)
 
Thank you for alerting us to this @Will Prowse

There are several fundamental problems around grounding on DIY projects.

1) Many of the inverter manufacturers do not provide adequate documentation on how the inverters deal with grounding. Growatt and MPP are among the worst at this (I have often said that it borders on criminal negligence on the part of the manufacturers).
2) There is a *lot* of misinformation on the web about grounding. (Thankfully, I have not seen too much of it here on this forum)
3) Grounding is far more complex than most people realize and far too many people do not understand grounding. Worse yet, many people that think they understand it, don't.
4) It is easy to build something that appears to work fine but is fundamentally unsafe because of the way the grounding and bonding are done on the project.

Add to that the use of products designed for one country being used in another country and it is a huge problem.

Agree.
I have seen 4 different type of MPP Solar and Growatt inverters grounding wise:
  • No inner PE - N relay (relay when blackout happens then connects inverter outgoing Neutral to Ground)
  • With PE - N relay (working and not working relay)
  • Menu 38 to enable inner relay
  • Fix inner bond between PE -N (one screw and a cable, can be separated)
There are even a special external relay for this inverters:
 
We need accurate schematics for all equipment. Not everyone has the same usecase and there isn't an issue here if you understand the design and account for it.

However, we don't, and to just learn the same unit might be different from ss and watt247, WTF?
 
Agree.
I have seen 4 different type of MPP Solar and Growatt inverters grounding wise:

Do you know whether they have SPST isolating only incoming line but not neutral from grid?
Or, do they have DPST relay and disconnect both line and neutral from grid?
 
Do you know whether they have SPST isolating only incoming line but not neutral from grid?
Or, do they have DPST relay and disconnect both line and neutral from grid?

I think two relay isolates Line and Neutral in the same time from grid.

The grounding is is a very serious problem here.
Many Axpert/MPP Solar and clones like EASun, Must, Powland and Growatt inverters do not have the inner N-PE relay
(double throw relay so outgoing N is connected to incoming N or PE).
Here it is in the inverter (red)

Double throw relay.jpg


So they do not know if this relay even exist in there inverter (or if it is working).
They use it floating the ground (in separated off-grid situation or in a blackout) ... and they do not even know about that.
Worst ... they think it is OK, even better in this way.
A guy even made a YT video about how the RCD behind inverter does not disengage when in off-grid mode ... and how good it is.

So here in the EU the opposite is the problem: not grounded neutral :)


And I hate that MPP/Axpert and others do not make a pic about how the inverter works.
Like this for Victron Multiplus II:
Victron3.jpg
 
N-G bond wouldn't be what grounds the case. It grounds the neutral (assuming case is grounded). Case needs a separate ground wire.
According to Ian, that is the way the case is grounded. Go to 1:30 mark in video, he shows there is continuity between N and G. Obviously the G goes to the case of the unit as an EGC. Also, go to the 6:15 mark.

At 3:15 mark, he explains how a Euro inverter is wired and the N-G bond.
 
I think two relay isolates Line and Neutral in the same time from grid.

If that is the case, it eliminates a serious concern I had, and can probably be made to operate safely with an autotransformer to establish 120/240V split phase.

The victron one below shows (a couple) DPST relays.
But L in going to L (AC Out 2) I don't understand.
L,N AC Out 1 is isolated on both poles from input (with two relays in series?) so could be made to work.

Seeing a DC/AC inverter between battery and AC OUT 1, I would ask about its architecture - isolated or not? What happens to voltage of battery terminals if "N" is driven to 120 VAC rather than ground?

Like this for Victron Multiplus II:
View attachment 79800
 
I went to the Growatt US site for the SPF 5000 ES and it doesn't list a UL certificate. It only lists EU certifications.

I then did a search for 'growatt' on the UL database. The only thing I found is a rapid shutdown system that was tested with some growatt inverters. I found no UL listed Growatt inverters. (Maybe I need to search on different terms?)
Yep I found the same thing yet Signature keeps saying it's UL Certified.
Another interesting one is when someone asks for DEYE Inverter certifications this is what is posted.

Deye UL

If you read it carefully it seems to say that the company SGS tested it and they say it is up to UL standards.
SGS is based out of Switzerland El Salvador and Iran :ROFLMAO: . They seems to have their fingers in half a dozen different certification areas.
 
I am joining the "me too" crowd. I have been banging on about this cheap hack since day one on here and asked SS about their new transformer the other day. Their reply was rubbish or a misunderstanding. Finally a proper discussion about this issue.
You can't teach common sense
 
Yep I found the same thing yet Signature keeps saying it's UL Certified.
Another interesting one is when someone asks for DEYE Inverter certifications this is what is posted.

Deye UL

If you read it carefully it seems to say that the company SGS tested it and they say it is up to UL standards.
SGS is based out of Switzerland El Salvador and Iran :ROFLMAO: . They seems to have their fingers in half a dozen different certification areas.
I did some digging in EE forums some time back, there are something like 12 different entities certifying electrical equipment.

What was interesting were the comments about UL. The cert isn't all that it is made out to be.
 
So many of us jumped into off grid solar after watching hours and hours of video. My wife endured six months of listening to them. Real answers are so difficult to find. Finally after months, I called Signature Solar. Most times just left a voice mail. I think David’s videos are what convinced me. Of course no one answers phones now. I want to say thanks to all who’ve responded to this thread. Special thanks to Will. Spoke with Ian this morning. Seriously thinking of duplicating Wills video. I will be selling three brand new Gowatts and two mid point transformers. I have 36 each 450 watt panels, fuses, everything ready- just need to make final tie ins. I really don’t want to do this again. Thoughts on LVX6048 versus LV6545. I also have 21kWh of lithium batteries. At 76, I’m almost too old for this. Thanks
 
If that is the case, it eliminates a serious concern I had, and can probably be made to operate safely with an autotransformer to establish 120/240V split phase.
But as I wrote there is 4 type :) The constant bond version is a problem for US.

The victron one below shows (a couple) DPST relays.
But L in going to L (AC Out 2) I don't understand.
Victron like the Deye have an inner and can have an outer limiter/meter/sensor too.
So AC out 2 is for non protected load ... but after the inner sensor so it generates power to it too (in inner sensor limiting mode)

L,N AC Out 1 is isolated on both poles from input (with two relays in series?) so could be made to work.
I think some countries recommend the double relay setup to isolate the inverter from main.
I do not think MPP/Axpert/Growatt has it ...

Seeing a DC/AC inverter between battery and AC OUT 1, I would ask about its architecture - isolated or not?
Yep, isolated. I think in the MPP/Axpert/Growatt too the DC/AC from battery is isolated. But I think the MPPT is not.


About working schematics. Coulomb in the South-African and Australian forums is an expert.
Here is the schemas he draw for the "batteryless" MPP Solar inverters like GK and MGX:
MPP_Solar_MGX_schema.png


And here is for the double conversion inverters like MPP Solar MK, MKX, LV-MK
MPP_Solar_MKX_schema.png




What happens to voltage of battery terminals if "N" is driven to 120 VAC rather than ground?
Nothing I think. Then the Line will be 120Vac too.
Actually when floating the ground there is also about 110-120V from L-PE and N-PE
 
Last edited:
If you read it carefully it seems to say that the company SGS tested it and they say it is up to UL standards.
SGS is based out of Switzerland El Salvador and Iran :ROFLMAO: . They seems to have their fingers in half a dozen different certification areas.
Most companies hire outside companies to do the UL testing so this is not alarming to me.
 
Most companies hire outside companies to do the UL testing so this is not alarming to me.
Oh yes I know, just like FCC certification is done by third party companies. Within the document they then list a UL certification number, but this one does not have one and the wording of the document implies its their own test and certification with just a lose reference to them using the "fundamentals of product certification" according to UL 1741.
It sounds like Pure Snake Oil to me.
 
Back
Top