SPF5000 ES leaking current on the casing/ground

Last year i ordered 2 Growatt 5kW Stackable Off-Grid Inverters | SPF 5000 ES-US plus two EG4-LifePower4 Lithium Batteries | 48V 100AH from Signature Solar.

I contacted them but still no answer so thought you guys might have an answer.

I just finished setting everything up. And everything is working correctly except that I have current on the inverter casing and everything metal that is connected to the casing. You will get a lite shock if you touch any of it. The wires, the screws on the sides and bottom, the communication cables etc.

This is when the solar, batteries and inverters are on.

The issue happens only if I turn on the solar on the inverter. If I just have the batteries connected and inverters on then I don't have the issue.

I also noticed that if the batteries and inverters are on and I don't connect the PV wires that there is current on the PV input.

This happens on both inverters.. so it seems like there is something wrong with the inverters. But also unlikely that both are defect.

I checked all wiring and I am 100% sure I connected everything correctly.

Any idea what the issue can be? Could it be that both inverters are defect?

I created a video to walk you trough my setup. I also added additional photo's.

Post up a wiring diagram, it appears you have objectionable current due to a parallel path between N and G.

Is the PV grounded with a EGC and ground rod?

How are you handling N/G bonding?

Zwy said:

Post up a wiring diagram, it appears you have objectionable current due to a parallel path between N and G.

Is the PV grounded with a EGC and ground rod?

How are you handling N/G bonding?

Click to expand...

Hi Zwy,

Thanks for your message. I am still a beginner so this was new to me. Thanks for pointing it out.

I quickly created a wiring diagram and attached it. Grounding is still a bit unclear to me. And opinions differ i noticed.

My setup is the same as a lot of other people with the same components and they it seems they don't have this issue. That confuses me.

This is off grid only?

There should be an EGC from PV to grounding electrode. Is there a grounding electrode at the main panel?

Do you have an auto transformer or isolation transformer?

One member running the 5000ES is @timselectric .

Zwy said:

This is off grid only?

There should be an EGC from PV to grounding electrode. Is there a grounding electrode at the main panel?

Do you have an auto transformer or isolation transformer?

One member running the 5000ES is @timselectric .

Click to expand...

Hi Zwy

Yes this is off-grid only. No AC input. No connection to my house/grid main panel.

The inverters are the US version from signature solar. So no ground/neutral bonding.

The transformer is the Solaredge mid-point transformer to get the 120volt/neutral.

There is no grounding electrode anywhere right now.

Guido81 said:

Hi Zwy

Yes this is off-grid only. No AC input. No connection to my house/grid main panel.

The inverters are the US version from signature solar. So no ground/neutral bonding.

The transformer is the Solaredge mid-point transformer to get the 120volt/neutral.

There is no grounding electrode anywhere right now.

Click to expand...

As this is off grid, it does make it easier. Always remember electricity will return to source which is the inverter.

The same applies for the PV, there should be an EGC from the PV to your system ground.

As for this inverter, I am familiar with some of the issues reported here in the forum. I would not own one personally. I suggest you read this thread. https://diysolarforum.com/threads/d...pf-5000-es-grid-backup-neutral-bonding.29717/

As to why you are receiving a shock, you most likely have voltage potential on the EGC. Where this voltage is coming from is the question. The first thing you need to do is have a ground rod at your main panel which has N-G bond. Then run an EGC from the main panel to your PV array so it is grounded to earth.

As you have voltage on PV input with PV disconnected, and both positive and negative are disconnected, there is a strong possibility the inverter has a defect. But you must ground the PV system first and install a ground rod.

I would be contacting Signature Solar about this problem and let their techs determine if a unit is defective.

Hi Zwy,

Thanks for taking the time for helping me out. Appreciate it.

I know all the discussion around this inverter and kind a wished i choose different ones. But i already had them and don't have the budget now to just replace them with new ones ;-)

Also one of the reasons why i don't connect to the grid and go completely off grid with this system. Half of my house will be off-grid and the other half with heavier loads will stay on the grid connected for now. Until i have enough solar power and batteries to take it all off grid.

Oke so as i understand i should ground it all. So one ground rod and ground the solar panels, inverters, solar main panel and the transformer to it?

Or do i ground the solar panels to it's own ground rod and the inverters, solar main panel and transformer to it's own ground rod?

I have seen both set ups being done.

Thanks!

Guido81 said:

There is no grounding electrode anywhere right now.

Click to expand...

DUDE

Zwy said:

As you have voltage on PV input with PV disconnected

Click to expand...

I don't know for sure how the battery and PV charger are connected internally, but I highly expect this is battery voltage on a common 48v buss.

Quattrohead said:

DUDE

Click to expand...

lol! Like i mentioned i am still in the set up and learning phase and wouldn't actually use the whole set up unless i am sure i got everything right.

I am also pretty sure that i saw a video by Will Prowse explaining why he didn't use a ground rod on his system.

But yeah it seems no matter what it is the better choice for sure.

Quattrohead said:

I don't know for sure how the battery and PV charger are connected internally, but I highly expect this is battery voltage on a common 48v buss.

Click to expand...

I don't know that either how it is connected internally. So you are saying that having some current on the PV input is normal? Or do you also think that there might be something wrong internally?

Thanks!

Guido81 said:

Hi Zwy,

Thanks for taking the time for helping me out. Appreciate it.

I know all the discussion around this inverter and kind a wished i choose different ones. But i already had them and don't have the budget now to just replace them with new ones ;-)

Also one of the reasons why i don't connect to the grid and go completely off grid with this system. Half of my house will be off-grid and the other half with heavier loads will stay on the grid connected for now. Until i have enough solar power and batteries to take it all off grid.

Oke so as i understand i should ground it all. So one ground rod and ground the solar panels, inverters, solar main panel and the transformer to it?

Click to expand...

One ground rod connected to grounding busbar in main panel of off grid system, all EGC's connect to the grounding busbar.

Guido81 said:

Or do i ground the solar panels to it's own ground rod and the inverters, solar main panel and transformer to it's own ground rod?

Click to expand...

That creates a voltage potential and loop thru the earth.

Guido81 said:

I have seen both set ups being done.

Thanks!

Click to expand...

Quattrohead said:

I don't know for sure how the battery and PV charger are connected internally, but I highly expect this is battery voltage on a common 48v buss.

Click to expand...

There is a common bus, the 5000ES can run without a battery and just on PV.

Zwy said:

One ground rod connected to grounding busbar in main panel of off grid system, all EGC's connect to the grounding busbar.



That creates a voltage potential and loop thru the earth.

Click to expand...

Hi Zwy,

Awesome thanks!

So then i just have one more question..

My grid main panel of my house must have a grounding rod near my house. Could i connect it to that same grounding rod? I got the feeling no but just want to confirm.

And if no then i have to place a separate grounding rod for my off grid system. By doing that i will have two ground rods. One from my grid main panel and one form my solar main panel. Does that not create any voltage potential/loop thru earth?

Thanks!

@Zwy

I mentioned to @Quattrohead that i saw a video of Will Prowse saying he doesn't use a ground rod.

I don't completely understand all he says but i am curious what your thought are on it. It's a 5 min video.
I absolutely will follow your advice on grounding but i am just curious about your opinion on this video. And if it even applies to my setup or is completely different.

Thanks!

Guido81 said:

Hi Zwy,

Awesome thanks!

So then i just have one more question..

My grid main panel of my house must have a grounding rod near my house. Could i connect it to that same grounding rod? I got the feeling no but just want to confirm.

And if no then i have to place a separate grounding rod for my off grid system. By doing that i will have two ground rods. One from my grid main panel and one form my solar main panel. Does that not create any voltage potential/loop thru earth?

Thanks!

Click to expand...

As long as the system is totally separate, you can add another ground rod. If you want to utilize the ground rod already in place, it would work.

Where the problem arises is when a system has 2 ground rods, it creates a voltage potential between the 2 ground rods.

Zwy said:

As long as the system is totally separate, you can add another ground rod. If you want to utilize the ground rod already in place, it would work.

Where the problem arises is when a system has 2 ground rods, it creates a voltage potential between the 2 ground rods.

Click to expand...

Hi Zwy,

Ah oke clear! Thanks!

Guido81 said:

@Zwy

I mentioned to @Quattrohead that i saw a video of Will Prowse saying he doesn't use a ground rod.

I don't completely understand all he says but i am curious what your thought are on it. It's a 5 min video.

I absolutely will follow your advice on grounding but i am just curious about your opinion on this video. And if it even applies to my setup or is completely different.

Thanks!

Click to expand...

Different type of system, you have an auto transformer in the mix.

Note he does mention excess static accumulation of PV.

Floating systems have their advantages. However one must remember for ground fault detection, 0V voltage potential is preferred.

Take a look at this video, even though the helo is not grounded to earth, there still is voltage potential. Notice how the rod is used to create a path before the wire is attached.

Zwy said:

Different type of system, you have an auto transformer in the mix.

Note he does mention excess static accumulation of PV.

Floating systems have their advantages. However one must remember for ground fault detection, 0V voltage potential is preferred.

Take a look at this video, even though the helo is not grounded to earth, there still is voltage potential. Notice how the rod is used to create a path before the wire is attached.

Click to expand...

Oke thanks! Cool video! ;-)

I will start grounding all my components. Hope that the current issue that i have will also be resolved then. I will update you when i am finished.

Thanks for all your help

@Zwy I have bought a 6 gauge grounding wire, grounding rod + clamp and lay-in lugs to connect to my solar panels.

So the question i have now is where do i put my grounding rod? Close to the solar panels or close to the house? My solar panels are about 30-40 meters away from the house.

I think close to the solar panels so that when lightning hits the solar panels the lighting can go back into the earth right away and not travel to my solar main panel first and then go to the grounding rod. I could of course be totally wrong lol!

Thanks
Guido