[RE-wrenches] Cell damage leading to ground fault?

[Dave Tedeyan]

Jason,
There are just two strings of panels, each going to their own MPPT. I could
certainly bypass this module. Unfortunately though, the fault is
intermittent, so it would take a while to know whether this was the issue
or not. But this is the only cell that looks like this in the entire array.
I have also been to this site once already recently to remedy some squirrel
damage. So it is possible as well that there is more squirrel damage that
we did not find in that first visit.

Cheers,
Dave

On Thu, May 8, 2025 at 3:41 PM Jason Szumlanski via RE-wrenches <
re-wrenches at lists.re-wrenches.org> wrote:

> Is this a single series string? Can you make a jumper and skip over the
> panel to test the string without the bad panel in series? If the error does
> not return, that could be the answer you are looking for.
>
> If there are parallel strings, jumper over one panel in each string.
>
> I'm not sure about damaged individual cells, but I am learning very
> quickly that solar panels that are submerged by hurricane storm surge are
> very likely to result in a PV Insulation Resistance fault. Yep, I have to
> deal with panels that have been swimming. Fun stuff.
>
>
>
> Jason Szumlanski
> Principal Solar Designer | Florida Solar Design Group
> NABCEP Certified Solar Professional (PVIP)
> Florida State Certified Solar Contractor CVC56956
> Florida Certified Electrical Contractor EC13013208
>
> On Thu, May 8, 2025, 3:23 PM Dave Tedeyan via RE-wrenches <
> re-wrenches at lists.re-wrenches.org> wrote:
>
>> Hello,
>>
>> There is an installation that I am servicing with the Q.Peak G4 modules,
>> where one cell has some visible damage. I am wondering whether this type
>> damage can lead to a ground fault? The Fronius inverter on site is
>> picking up an "Insulation Resist" error. I am wondering whether this could
>> be the cause, or whether I should look elsewhere in the array. A photo is
>> attached. Any thoughts would be appreciated.
>>
>> Thanks!
>> Dave
>>
>> --
>>
>> [image: Logo] <https://www.sungineersolar.com/>
>> Dave Tedeyan, P.E.
>> Owner | Sungineer Solar
>> p: he | him | his
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>>
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