Sol-Ark/Solar/Solaredge system problem

[woundedpig]

I have a 13.9 kW array, Solaredge SE 11499H grid tied inverter, and 2 X 12K Master/slave Sol-Ark/SimpliPhi lithium battery backup system. AC coupled on the load side. No generator. Battery backup system installed about 2.5 years ago. Came home yesterday to find most house circuits out. No battery backup occurring. Solaredge grid tie inverter suddenly stopped capturing solar power yesterday around 1115. No LED’s on in the inverter toggle area. Full Solaredge resets did not fix the problem. Grid power intact. Don't know about any power surge. No storms.

Sol-Ark/Simpli-Phi battery back up system seems to briefly pass grid power for a couple seconds and then turns off. During the brief instant that the power is on, the Solaredge LED’s come on. The Sol-Ark’s have a brief click as the power briefly comes on. The critical panel circuits are not energized except for that couple seconds, turning off/on every 5-10 minutes or so.

The circuits not included in the critical circuits panel all work. A few weeks ago, with a brief power outage, the battery backup did not kick on, though the non-critical circuit panel was energized when the grid power returned. The Solaredge LED’s were blinking (?pattern). A full reset seemed to restore power and monitoring platform communication, though I don’t get how a Solaredge reset would help that.

In some ways, this sounds like a transfer switch or relay issue. ?Any guidance here.

 

[BentleyJ]

The 12K inverters most likely didn't both fail at the same time so one of them may still work.

Turn off the battery, grid & load breakers to both Sol-Ark units. EDIT: Turn off the PV inputs as well. I'm thinking maybe also disconnect the parallel cable between them so as to isolate each. Turn off the Solaredge system as well at the disconnect. Turn off all the breakers in the critical loads panel.
Pick one Sol-Ark unit and turn on only the battery breaker to verify that Inverter will stay on and the display shows information and maybe an error since the other inverter is off and they are set up to be a pair. If the inverter shuts down, turn off the battery breaker and try the other inverter. Assuming 1 of them stays on:

Go to the menu and set that unit up as a stand alone Inverter so it can function independently. Turn on the inverter load breaker and then turn on a couple of breakers in the backup panel. Verify the inverter is supplying power from batteries and supporting loads, preferably a 240V load.

 

[woundedpig]

I had found a system power down sequence - turning off PV disconnect, flipping battery, grid, anad load breakers off. Turning power button off, then reversing the sequence. I had also flipped off breakers to most all of the critical loads. The system restarted. Then flipped the PV disconnect back on, and the Solaredge had monitoring communication within a few minutes. Solar being captured. Grid power coming thru to both the critical load panel and the circuits not backed up. Seeing a F29 Parallel_CANBus_Fault on the Sol-Ark cloud and a F56 DC_VoltLow_Fault on the inverters - don't know if that one occurred because I hadn't switched the batteries on yet. After the lithium bank reached 100%, the Sol-Ark showed power being sent to the grid. AC and Normal green lights are on.

So things seem to be back to normal, but without an explanation. This is an issue the way this all went down, as we have both a well pump and rainwater harvest tank pumps that are backed up, a decision made in the aftermath of the 8-9 day snow/icemageddon that happened in Texas a while back. So we had no water, two freezers without power, etc. I have been searching for a fix and of course have a "ticket" with SolarEdge and a call into the installer, but the responses are typically glacial.

I wonder if I need some type of bypass if the forced pass thru via the Sol Arks doesn't work. I know quite a bit about RV solar and have done some complicated installs, but this system is more complex.

 

[woundedpig]

An update. The full system power down sequence and then reversed restored grid power and the the SolarEdge woke up and began capturing solar and communicating. I just completed a test where I shut down both main breakers to the house and workshop - two separate 200 amp services. I had decreased the number of larger amp-consuming items from the critical load panels prior to this.

The switchover to battery backup was seamless. We have sometimes seen a flicker of light when the switchover occurred but the changeover was barely perceptible this time. The backed up circuits were energized. Going back to grid power was uneventful.

This is all well and good, but I still have no explanation for what happened. A tech from the installer hypothesized that the Solaredge had seen too high a voltage and went into a sleep mode. That doesn't explain the bizarre twitching behavior of the Sol-Ark's. Plus, we routinely see much higher solar capture in the months of June-August - it's only April now.