[RE-wrenches] Sol-Ark 15K AC Coupling

Sat Aug 24 17:02:48 PDT 2024

Hi Kirpal,

This is hugely helpful. More than you can imagine. I actually brought this
up with tech support because two of the inverters have Savant insignia on
them. The first slave inverter does not have this insignia. I did not
supply these inverters, as the customer already had them from another
contractor who was fired from the job. I do not know the supply chain
origin or the timing of receipt of these inverters. I was told by tech
support that it doesn't matter because what matters is the firmware
version. But I am skeptical. Incidentally, the slave one inverter was the
one that would show the F41 fault in red on the display, but the others did
not. That said, the fault was sometimes recorded in the system alarms log
on the others as well.

It is another thing to consider in this investigation. I think the issue is
with the AC coupling, but if the issue persists with AC coupling turned
off, I will pursue this avenue of inverter hardware mismatch in the
diagnostic process.

It's entirely possible that these inverters are all identical and the
Savant labeling is irrelevant, but I appreciate your input.

I did not have the luxury of shutting down the two slave inverters because
this system is powering a three bedroom single family home plus six
cottages, and the base load is roughly 5,000W with seven air conditioners
on site, plus well and pressure pumps, refrigeration, and much more. The
master alone cannot handle the surge required for everything. In fact, this
is actually a four inverter system with the 4th inverter about to come
online. It was previously powering a construction shed. I am hesitant to
parallel in the 4th inverter until this issue is resolved with the three
inverters already in service.

I have been in contact with my sales person at Sol-Ark about the technical
support issues I experienced. It is no secret that I have been a strong
advocate of Enphase in this forum. While their first tier technical support
team doesn't always have the answers, I always have direct access to the
engineering team, having made deep contacts over the last 15 years
installing their products. I try to reserve my contacts with them to
serious issues because I know they're busy. But at least they are
accessible. With Sol-Ark and other brands, it seems like we are on our own
to resolve many technical issues, and escalating issues isn't easy at all.

The winners in the inverter manufacturing game are going to be the ones
that provide stellar support for their dealer networks. We will see who
rises to the top. These forum discussions are very productive in steering
solar professionals toward products they can reliably support over the long
term.

Jason Szumlanski
Florida Solar Design Group

On Sat, Aug 24, 2024, 7:28 PM Kirpal Khalsa via RE-wrenches <
re-wrenches at lists.re-wrenches.org> wrote:

> Jason...
> We had a similar situation with a dual SolArk 15K system. After
> approximately an hour of turning system on we would get the F41 error on
> the master ‐ the slave inverter would show an error and then the master
> would shut down with the paralleling error F41 because the slave inverter
> had shown an error related to a neutral ground bond in more than one place
> detected.. we confirmed there was not more than one neutral/ground bond in
> the system.  It didn't seem to matter which loads or total power levels it
> kept shutting down with the same pattern.
> They had us revert both firmwares back to the 925 version instead of 926.
> Same problem still with either firmware version.
> Finally we disconnected the slave and ran the master on its own- like
> magic - Problem solved.
> Upon close inspection we noticed that  the slave unit had different color
> PV input terminals than the master. There were different capacitors up
> above the AC in/out terminals and some adittional circuitry we guessed
> related to a rapid shutdown heartbeat signal for the solar circuits.
> Turns out the inverters were different vintages of the same model of
> 15K-2P inverter but the boxes they shipped in were the same part numbers-
> but there were obvious differences in the physical build and circuitry.
> We pointed this out and they agreed to send us a replacement inverter of
> the same vintage as the master...
> This solved the f41 paralleling issue we were having.  They also said the
> 925 firmware was better for all the inverters to be on in multi inverter
> systems versus the more sensitive (and newer) 926 firmware. We havent had
> an issue since matching vintages of inverter build were used.
> Look carefully at all three inverters and make sure they are physically
> the same build version.
> It was a frustrating detective experience and we bore the costs associated
> with replacing the inverter.
> If that is a facet of your system I would ask them to replace your
> inverter(s) to be the same build vintage. It solved the problem for us but
> was a long battle with tech support to seluth out the problem and to get
> them to agree to swap inverters.
> Good luck and keep us posted on your resolution.
> Thanks.
> Kirpal
> Oregon Solarworks
>
>
>
>
> On Sat, Aug 24, 2024, 11:32 AM Jason Szumlanski via RE-wrenches <
> re-wrenches at lists.re-wrenches.org> wrote:
>
>> Hi all,
>>
>> Over the last three days I have had one of this infuriating and
>> frustrating experiences with Sol-Ark where you talk to 3 people and get 10
>> different answers. At least I think I finally got the right one today. Here
>> is the scenario and problem I was experiencing:
>>
>> At a (very) remote location that is a boat ride away, I have three 15K
>> inverters paralleled in a 120/240V system, off-grid, generator connected to
>> the grid input (but not being used). The PV array connected to the DC
>> inputs totals 40kW split across the three inverters. There is a 9.7kW
>> Enphase system (8.4kW AC inverter rating) connected on the load side of the
>> inverter outputs. Massive battery - 110kWh. Everything has been working
>> well for a couple of weeks since we got it set up.
>>
>> Then, over the last three days, we began experiencing unexpected
>> shutdowns where the inverter would repeatedly stop inverting and PV would
>> stop charging. There was usually no indication of errors on the screen.
>> Everything was just stopped, but the inverters remained on. Sometimes they
>> would restart once, only to shut down again relatively quickly. We had to
>> manually restart the inverters with the ON/OFF buttons. Then we started
>> getting various errors, with F50 being the strange one that is not
>> documented. I reached Sol-Ark, and they said the F50 points to an AC input
>> issue, but the generator was not on, so that didn't make sense. I was on my
>> own to double-check all of the wiring.
>>
>> But there was also an F41 Parallel System Stop error, which pointed me to
>> that suggested cause. I realized that one of the inverters had a -1725 COMM
>> firmware, whereas the others had -1726. I don't know how that happened
>> because I'm certain that I had them all on the same firmware at one time.
>> Anyway, I spent all day yesterday trying to reach Sol-Ark and getting the
>> firmware to match. I thought we had the issue resolved by the time I
>> left, as I was able to run the system for an hour without a shutdown.
>>
>> Then I got a call at noon today from the owner. Same problem. System shut
>> down.
>>
>> I was able to reach Sol-Ark immediately this time and the agent gave me a
>> more plausible answer. He said the F50 error points to something wrong with
>> the AC coupling. We started to put our heads together and I realized that
>> this issue first popped up around mid-day on Thursday, and then repeated
>> itself mid-day on Friday. Here we are again today, and I get the call at
>> noon. It seems like the issue happens as soon as the batteries reach 100%
>> capacity. It's like the Sol-Ark is not commanding the IQ8A microinverters
>> to shut down. I had the owner shut off the AC coupling input breaker and I
>> remotely unchecked the box for AC coupling on the load side. That seems to
>> have resolved the issue.
>>
>> Ok, fine, but how do we resolve this (I asked Sol-Ark)? The "solution" I
>> was offered is to move the AC coupled input to the GEN terminals. The
>> problem is that I need to reserve the GEN terminals for an upcoming Smart
>> Load subpanel. That's why I installed the AC coupling on the load side,
>> which is a documented and accepted practice.
>>
>> I do have AC coupling working without issue on a grid-tied system at
>> another location with dual Sol-Arks, but that is connected to the GEN
>> terminals. This is the first time I have AC coupled on the load side. Has
>> anyone successfully AC coupled on the load side, particularly with
>> microinverters?
>>
>> I'm probably going to have to climb the customer service ladder at
>> Sol-Ark to get a resolution for this, but I wanted to get some feedback
>> in case someone has already been down this road.
>>
>> Thanks in advance,
>>
>> Jason Szumlanski
>> Florida Solar Design Group
>>
>>
>>
>>
>>
>>
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