Shocked by Shed please help!

[Ennis437]

Today I went to open the handle of my shed and I got a nasty jolt, please help!! Here is my setup I have 8 450 watt panels on my shed. They are going to two SunGold power SP 6548 that I have in split phase. My AC in from the grid is going to both of my inverters. The main panel has neutral ground bond. My AC OUT then goes TO MY SUBPANEL where I have the grounds and neutrals separated. After getting shocked I grabbed my voltage meter and the entire shed was showing anywhere from 3 volts to 10 volts AC when I shut off my circuit breaker to the panel array that’s on the shed roof the voltage went to 0. I tried shutting down several things and the only thing that seems to stop that current on my shed is to kill the breaker for that Array or to shut down my inverters . Any thoughts? Thanks!

 

[Mattb4]

Ground your shed. Sounds like the classic AC to panel frame issue.

 

[Ennis437]

Ground your shed. Sounds like the classic AC to panel frame issue.

Ok so are you referring to earth grounding the panels on the shed?

 

[Sanwizard]

Ok so are you referring to earth grounding the panels on the shed?

Interjecting here, but Yup, the panel frames and the shed frame to ground. I believe its best to run your panel ground back to the main panel ground, so you have only one main ground.
Maybe supply a wiring diagram so it makes what you currently have clear?

 

[Ennis437]

Interjecting here, but Yup, the panel frames and the shed frame to ground. I believe its best to run your panel ground back to the main panel ground, so you have only one main ground.
Maybe supply a wiring diagram so it makes what you currently have clear?

My inverter specifically says no grouting , here is from the manual .

14. WARNING: Because this inverter is non-isolated, only three types of PV modules are acceptable:
single crystalline, poly crystalline with class A-rated and CIGS modules. To avoid any malfunction, do not connect any PV modules with possible current leakage to the inverter. For example, grounded PV modules will cause current leakage to the inverter. When using CIGS modules, please be sure NO grounding.

 

[Ennis437]

My inverter specifically says no grouting , here is from the manual .

14. WARNING: Because this inverter is non-isolated, only three types of PV modules are acceptable:
single crystalline, poly crystalline with class A-rated and CIGS modules. To avoid any malfunction, do not connect any PV modules with possible current leakage to the inverter. For example, grounded PV modules will cause current leakage to the inverter. When using CIGS modules, please be sure NO grounding.

Or is this referring to ground conductors and not “Earth ground”. This is incredibly confusing!!

 

[LydMekk]

Yes. Ground your rails and frames. Now.

 

[Mattb4]

Ok so are you referring to earth grounding the panels on the shed?

Frames only. Typically metal sheds are earth grounded. The instructions you have are a warning not to connect the negative lead from the panels to ground. Pos and neg from the panels only connect to the corresponding terminals at the SCC (AIO).

 

[Sanwizard]

My inverter specifically says no grouting , here is from the manual .

14. WARNING: Because this inverter is non-isolated, only three types of PV modules are acceptable:
single crystalline, poly crystalline with class A-rated and CIGS modules. To avoid any malfunction, do not connect any PV modules with possible current leakage to the inverter. For example, grounded PV modules will cause current leakage to the inverter. When using CIGS modules, please be sure NO grounding.

Yeah, my MPP LV6048's had the same warning. I believe they mean grounding the DC negative on the panels, and not the frames. Your frames need to be properly grounded to pass code. You also need some lightning protection, so adding a midnight solar SPD would help.

 

[Liam M]

Yeah, my MPP LV6048's had the same warning. I believe they mean grounding the DC negative on the panels, and not the frames. Your frames need to be properly grounded to pass code. You also need some lightning protection, so adding a midnight solar SPD would help.

great explanatory video!
Is it yours?

 

[Sanwizard]

great explanatory video!
Is it yours?

Nope.

 

[Toinfinityandbeyond]

Today I went to open the handle of my shed and I got a nasty jolt, please help!! Here is my setup I have 8 450 watt panels on my shed. They are going to two SunGold power SP 6548 that I have in split phase. My AC in from the grid is going to both of my inverters. The main panel has neutral ground bond. My AC OUT then goes TO MY SUBPANEL where I have the grounds and neutrals separated. After getting shocked I grabbed my voltage meter and the entire shed was showing anywhere from 3 volts to 10 volts AC when I shut off my circuit breaker to the panel array that’s on the shed roof the voltage went to 0. I tried shutting down several things and the only thing that seems to stop that current on my shed is to kill the breaker for that Array or to shut down my inverters . Any thoughts? Thanks!

I asked SumGoldPower about the grounding of my panels. And this is what I received:

“It is not recommended to ground the solar panels, and it is not recommended to connect the ground of the PV and the ground of the inverter together. The PV will have some leakage current, which will flow to the inverter through the ground and damage the inverter. If the solar panels must be grounded, then the inverter does not need to be grounded. If both of them need to be grounded, then the PV ground and the inverter ground should be isolated from each other.”

I have the 6.5KW DC 48V pure sine wave AC output 120V, Built-in MPPT solar charger max 120A and utility battery charger max 120A, Max PV input 390V (VOC), Dual PV input. UL 1741 Standard Listed by TUV / CSA / FCC.

 

[robbob2112]

Yo @timselectric , you seem like a grounded guy that might have input

 

[ksmithaz1]

Naw, Someone is spewing what someone told them, because someone told them and the context is wrong. People just associate the negative lead with "ground" like a car, or other appliance that uses DC which causes confusion. "Need Plus here, ground there to make the connection".

It's pretty simple and boils down to:

Your PV +- leads need to be isolated and direct to the MPPT inputs, no attachments to "Earth"/ground. Any other metal should be grounded to a common earth ground with a single point of attachment for all above the earth components to the in the earth ground components (ground rods/piping/whatever is in the dirt).

Same for any DC batteries, +- direct to the battery inputs on the inverters, ground all chassis/metal to the common ground point. Do not attach (-) to earth.

On the AC side Neutral should attach to ground in only one place at the first distribution point (The primary breaker panel). That should be connected to the very same common earth ground point of attachment.

Anything metal that has electricity in, around, or thru it gets grounded to earth in the same way via the single point of entry to the dirt.

Most of the confusion is around the common point between above the earth and below. They used to let you drive a ground rod 100ft away from the building ground rod that is grounding everything else drag power over and call it grounded. Further research has determined this is sub-optimal, you need to drag the ground over along with it for maximum safety.

 

[ksmithaz1]

And frankly, if I had an AIO that backfed AC onto the PV leads, I would get rid of it, though apparently that is an issue with some of these units.