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<p class="MsoNormal"><span style="font-size:11.0pt">Jason, You might need some more sophisticated equipment to diagnose the problem. It is possible that the Enphase system is not responding correctly to the Solark frequency adjustments as the battery gets full.
We use our power analyzer to diagnose these sorts of issues, The power analyzer is an expensive piece of equipment so not many installers use them. Depending on the ”grid tied inverter” brand and the loads being operated at the site all sorts of site-specific
anomalies can occur. With Solark specifically sometimes enabling things like active power factor correction can help. I realize that at times AC coupling is the most viable solution but generally speaking we avoid it wherever possible. I have never witnessed
AC coupled systems control the grid tied inverters in a proportional way, the systems I have witnessed operate in a stepped manner. If the site loads are less than the Enphase output capacity, and the batteries are at a high state of charge you can potentially
have power factor issues and see the Enphase system output power swing up and down.
<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt"> If you monitor the system, it is possible that the Solark inverters are commanding the IQ8A inverters to reduce power and eventually shut down, but the Enphase system is not responding correctly.
Have you looked to see if the Solark system is adjusting? If so, have you verified the Enphase system is responding ? If the battery voltage is staying within the limits, you set it is possible that the Enphase system is not responding, and the Inverter is
shutting down to protect the batteries.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt">Pieter Huebner<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt">Project Manager<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt">Off grid Enterprises<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt"><o:p> </o:p></span></p>
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<p class="MsoNormal"><b><span style="font-size:11.0pt;font-family:"Calibri",sans-serif">From:</span></b><span style="font-size:11.0pt;font-family:"Calibri",sans-serif"> RE-wrenches <re-wrenches-bounces@lists.re-wrenches.org>
<b>On Behalf Of </b>Jason Szumlanski via RE-wrenches<br>
<b>Sent:</b> Saturday, August 24, 2024 1:32 PM<br>
<b>To:</b> RE-wrenches <re-wrenches@lists.re-wrenches.org><br>
<b>Cc:</b> Jason Szumlanski <jason@floridasolardesigngroup.com><br>
<b>Subject:</b> [RE-wrenches] Sol-Ark 15K AC Coupling<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-family:"Arial",sans-serif">Hi all,<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-family:"Arial",sans-serif"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span style="font-family:"Arial",sans-serif">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:<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-family:"Arial",sans-serif"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span style="font-family:"Arial",sans-serif">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.<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-family:"Arial",sans-serif"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span style="font-family:"Arial",sans-serif">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.<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-family:"Arial",sans-serif"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span style="font-family:"Arial",sans-serif">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.<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-family:"Arial",sans-serif"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span style="font-family:"Arial",sans-serif">Then I got a call at noon today from the owner. Same problem. System shut down.<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-family:"Arial",sans-serif"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span style="font-family:"Arial",sans-serif">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.<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-family:"Arial",sans-serif"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span style="font-family:"Arial",sans-serif">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.<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-family:"Arial",sans-serif"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span style="font-family:"Arial",sans-serif">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?
<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-family:"Arial",sans-serif"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span style="font-family:"Arial",sans-serif">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.<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-family:"Arial",sans-serif"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span style="font-family:"Arial",sans-serif">Thanks in advance,<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-family:"Arial",sans-serif"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span style="font-family:"Arial",sans-serif">Jason Szumlanski<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-family:"Arial",sans-serif">Florida Solar Design Group<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-family:"Arial",sans-serif"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span style="font-family:"Arial",sans-serif"><o:p> </o:p></span></p>
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