[RE-wrenches] Sol-Ark 15K2P F20 MPPT Overcurrent Error

Sun Apr 12 10:14:14 PDT 2026

Vince and Wrenches,

We also recently encountered this F20 error on a relatively new off-grid
system and are still working through it. The system will go weeks without
doing it, then do it twice in a day.

The system consists of:
1 Sol-Ark 15kW
30kWh Discover Rackmount with Lynk2
28 REC430AA Pure 2 modules
28 AP Smart RSD-S-PLC
1 TRANSMITTER-PLC with 2 cores

Firmware:
Sol-Ark MCU 7.2.2.8 Comms 1.4.5
Rackmount - 4.11.1
Lynk2 - 2.6.0

Smartload is utilized and it is charging an EV at 22A. The F20 occurs
whether the Smartload is activated or not.

Similar to you, Sol-Ark blamed the AP Smart RSDs hence the dual cores and
odd (almost impossible) current spikes up to 22.7A logged on the
Solarkcloud.

We will keep you posted if we find a solution but all signs point to a
inverter replacement. Too odd and too intermittent to be anything else in
my opinion.

Lou Russo
Owner
lou at spreesolarsystems.com
Office - 808 345 6762
Direct Line - 808 731 1907
Spree Solar Systems LLC
CT-34322

On Sun, Apr 12, 2026 at 2:36 AM Jay via RE-wrenches <
re-wrenches at lists.re-wrenches.org> wrote:

> Is this a common problem with Sol Ark inverters?
>
>
>
> On Apr 12, 2026, at 5:40 AM, david quattro via RE-wrenches <
> re-wrenches at lists.re-wrenches.org> wrote:
>
> 
> In a similar vein of thought, it may be helpful to only engage one string
> at a time to hopefully isolate error codes.
>
>
>
> On Sat, Apr 11, 2026 at 8:36 AM Jason Szumlanski <
> jason at floridasolardesigngroup.com> wrote:
>
>> You might consider taking this one step further and physically
>> disconnecting one string at a time. Since the error happens multiple times
>> a day, maybe you can isolate the issue to one string.
>>
>>
>> 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 Fri, Apr 10, 2026 at 7:56 PM david quattro via RE-wrenches <
>> re-wrenches at lists.re-wrenches.org> wrote:
>>
>>> i would swap which strings go into the different MPPT's to see if each
>>> specific problem follows the DC string // or do they follow the MPPTs.
>>> Another option is kinda a lot of work but might be worth it - take a
>>> different inverter out there and "bench test" it with those strings
>>> unadulterated
>>> Good luck and please let us how this one resolves.
>>>
>>>
>>>
>>> On Fri, Apr 10, 2026 at 4:05 PM Vince McClellan via RE-wrenches <
>>> re-wrenches at lists.re-wrenches.org> wrote:
>>>
>>>> Hello Wrenches
>>>> Has anyone else on this list had issues with a Sol-Ark 15K2P randomly
>>>> shutting down several times a day with an F-20 MPPT overcurrent error? The
>>>> errors are occurring when the system is well under the max amperage per
>>>> MPPT of 26 amps. We've had the inverter turn itself off when the online
>>>> data shows 12.5 amps max. I realize that Sol-Ark's online data updates only
>>>> every 5 minutes, so I could be possible that there is a spike that the
>>>> online data isn't showing, but the array is in full sun with the same
>>>> number of modules and the same string configuration on all 3 MPPT's.
>>>>
>>>> We are also seeing other anomalies such as MPPT 1 at 12 amps with MPPT
>>>> 2 and 3 at 22 amps. Again, with the solar array in full sun, no clouds, and
>>>> no shade.
>>>>
>>>> Sol-Ark originally thought it was because of an issue with Tigo RSD
>>>> switches, but we don't use Tigo. We've had way too many issues with Tigo
>>>> products.
>>>>
>>>> We've had people suggest that we're seeing the results of an edge of
>>>> cloud affect, but there are not clouds to cause this.
>>>>
>>>> We've also tested all the circuits with a insulation tester in every
>>>> possible configuration, and tested our wiring to insure there were no
>>>> mistakes by ringing it out with a multimeter. The wiring is good.
>>>>
>>>> Sol-Ark tech support doesn't seem to know what the issue is, but they
>>>> are assuring us that it's not their inverter at fault.
>>>>
>>>> I could use any suggestions that come to mind. I'm not sure what else
>>>> to try at this point.
>>>>
>>>> Thank you,
>>>>
>>>>
>>>> Vince McClellan
>>>>
>>>> President
>>>>
>>>> NABCEP PV Professional
>>>>
>>>> p: 541-485-8122
>>>>
>>>> a: 860 Conger St. Suite 12,. Eugene, OR 97402
>>>> <https://www.google.com/maps/search/860%0D%0AConger+St.+Suite+12,.+Eugene,+OR+97402?entry=gmail&source=g>
>>>>
>>>> e: vince at solarenergydesgin.com
>>>>
>>>> w: SolarEnergyDesign.com
>>>>
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