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

[Dave Tedeyan]

Jay,
Not a bad idea to spray the array down in general. That would certainly
help if I can recreate the issue, and then do it again after making any
repairs or bypassing modules to see if it happens again.

Although, does anyone know whether the Fronius (Primo) Inverters only do
the insulation resistance test first thing in the morning when it wakes up,
or whether it constantly checks this sort of thing? I am guessing a hard
ground fault would get picked up immediately, but just having an insulation
resistance lower than some threshold might not get picked up until the
following morning (or maybe an inverter reset).

Based on answers here, and knowing that there was previous squirrel damage,
I am guessing its more likely that squirrels are to blame rather than this
one cell. (I am pretty sure those jerks are in cahoots with the oil
companies).

On Thu, May 8, 2025 at 10:46 PM Jay via RE-wrenches <
re-wrenches at lists.re-wrenches.org> wrote:

> Sometimes spraying soapy water onto the suspect panel is enough to
> recreate the issue. A simple spray bottle will do.
>
>
>
> On May 8, 2025, at 6:28 PM, David Coale via RE-wrenches <
> re-wrenches at lists.re-wrenches.org> wrote:
>
> I am having the same issue, but it is with an SMA inverter.  In my case
> it happens when it is raining and clears up when it dries out.  I can see
> there are some bad cells, but they are right next to the edge of the panel
> so a moisture problem would show up this way.  Good to know about sealing
> the conduits.
>
> In your case, you should be able to disconnect the suspected string or
> jump around the suspected panel and figure this out.  Other wise I would
> blame it on the squirrels.  But then again, I blame everything on rogue
> squirrels or rats.
>
> David
>
>
> On May 8, 2025, at 12:55 PM, david quattro via RE-wrenches <
> re-wrenches at lists.re-wrenches.org> wrote:
>
> Fronius install manual says the conduit entry ports need to be packed with
> putty around the wires. They’re the only manufacturer I know of that
> requires this. Water vapor roses into the circuit boards.    I used to get
> a couple different error codes until we packed the conduits.
>    Good luck, and let us know!
>
>
>
> On Thu, May 8, 2025 at 12:22 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
>>
>> --
>>
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