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

Sat Aug 24 14:07:21 PDT 2024

Good information. Thank you.

I don't believe the Sol-Ark is capable of tapering AC coupled sources. It
is either on or off. I know if you connect an AC coupled source to the GEN
input(s) you can change the set points for when AC coupling starts and
stops based on battery voltage or state of charge. However, it is unclear
how these inverters manage AC coupled sources when connected on the load
side. It does not appear to be documented when the inverter will shift the
frequency to turn off the AC coupled source when it is connected on the
load side.

Anyway, I think I'm going to go ahead and move the AC coupled source to the
GEN terminals. This will provide more positive control hopefully where I
can shut down the AC coupled source when the battery reaches 90% state of
charge and turns back on when it dips below 70% or 80%.

If I need to put a smart load panel in, I can rig up a custom solution with
a voltage sensitive relay and contactor feeding a subpanel. The only smart
load capability I am looking for is to limit golf cart charging and
operation of a specific air conditioning unit when battery capacity is low.
It should be pretty easy to put something together to drop those loads when
necessary. It would be great if these inverters had low voltage auxiliary
relays to handle this logic.

Jason

On Sat, Aug 24, 2024, 3:32 PM pieter offgridenterprises.org via RE-wrenches
<re-wrenches at lists.re-wrenches.org> wrote:

> 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 <re-wrenches-bounces at lists.re-wrenches.org> *On
> Behalf Of *Jason Szumlanski via RE-wrenches
> *Sent:* Saturday, August 24, 2024 1:32 PM
> *To:* RE-wrenches <re-wrenches at lists.re-wrenches.org>
> *Cc:* Jason Szumlanski <jason at floridasolardesigngroup.com>
> *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
>
>
>
>
>
>
>
>
>
>
>
>
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