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.
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.
Pieter Huebner
Project Manager
Off grid Enterprises
From: RE-wrenches <[email protected]> On Behalf Of
Jason Szumlanski via RE-wrenches
Sent: Saturday, August 24, 2024 1:32 PM
To: RE-wrenches <[email protected]>
Cc: Jason Szumlanski <[email protected]>
Subject: [RE-wrenches] Sol-Ark 15K AC Coupling
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
_______________________________________________
List sponsored by Redwood Alliance
Pay optional member dues here: http://re-wrenches.org
List Address: [email protected]
Change listserver email address & settings:
http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org
There are two list archives for searching. When one doesn't work, try the other:
https://www.mail-archive.com/[email protected]/
http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org
List rules & etiquette:
http://www.re-wrenches.org/etiquette.htm
Check out or update participant bios:
http://www.members.re-wrenches.org
