Sorry for the long post! We installed a grid-tied Sol-Ark 12K inverter with 8.5 KW solar panels and 12 KWH BigBattery (Kong). The Sol-Ark feeds a critical loads panel and is connected to the grid through the house main breaker panel. Everything worked PERFECTLY for 26 months (from installation in July 2021 until Sept. 2023). In September, the BigBattery had tripped and in the process of troubleshooting Sol-Ark pushed an update to the inverter. The update was interrupted by internet outage but was pushed again a day later. We never determined why the battery tripped (I suspect someone inadvertently bumped into the switch which sticks out on the side of the battery), but since that time the Sol-Ark disconnects from the grid numerous times every day. I’m starting to believe the update is the cause of our problems. Many hours of Sol-Ark tech support have not solved the problem.
Our utility provider and our neighbors are not aware of any problems with the grid, and appliances and lights on the main house panel never flicker. I have recorded the detail screen on the Sol-Ark during the disconnects and it shows the grid frequency being the first number to drop to zero but other than that, the frequency is rock steady at 60Hz. The only other number I’ve ever seen is 59.8Hz. The Sol-Ark detail screen never shows the grid voltage outside a 118-122 range except when I use the 240V, 80A EV charger from the main house panel. Voltage drops to 117V then but it never causes the inverter to disconnect. The Sol-Ark’s grid voltage and frequency settings have been increased to VERY wide ranges without significant improvement.
There have been occasions where the inverter disconnected at the same time (12:37 am for example) three nights in a row. We haven’t been able to correlate the disconnects with anything. When I isolate the inverter from the grid and main house panel, everything works perfectly. With the inverter connected to the grid, I have turned off every breaker, unplugged major and minor appliances on the main house panel but the inverter still disconnects randomly. Turning off the PV or battery does not stop the disconnects.
I have also checked every electrical connection I can think of and nothing that I was able to tighten improved the situation. We even swapped out the inverter with another Sol-Ark 12K (refurbished, also with up-to-date software) but still experience the disconnects.
Our utility provider and our neighbors are not aware of any problems with the grid, and appliances and lights on the main house panel never flicker. I have recorded the detail screen on the Sol-Ark during the disconnects and it shows the grid frequency being the first number to drop to zero but other than that, the frequency is rock steady at 60Hz. The only other number I’ve ever seen is 59.8Hz. The Sol-Ark detail screen never shows the grid voltage outside a 118-122 range except when I use the 240V, 80A EV charger from the main house panel. Voltage drops to 117V then but it never causes the inverter to disconnect. The Sol-Ark’s grid voltage and frequency settings have been increased to VERY wide ranges without significant improvement.
There have been occasions where the inverter disconnected at the same time (12:37 am for example) three nights in a row. We haven’t been able to correlate the disconnects with anything. When I isolate the inverter from the grid and main house panel, everything works perfectly. With the inverter connected to the grid, I have turned off every breaker, unplugged major and minor appliances on the main house panel but the inverter still disconnects randomly. Turning off the PV or battery does not stop the disconnects.
I have also checked every electrical connection I can think of and nothing that I was able to tighten improved the situation. We even swapped out the inverter with another Sol-Ark 12K (refurbished, also with up-to-date software) but still experience the disconnects.
- Is the grid actually too unstable for the Sol-Ark? And maybe the inverter display is too slow to show the spikes? How can I monitor for this? The utility say they can’t do it.
- Could there be a bad connection somewhere in our system that I haven’t found?
