Grid Alarms: OV-G-V, UN-G-F, OV-G-F, UN-G-F

Created by Michael Allen, Modified on Thu, Dec 18 at 7:38 AM by Michael Allen

The inverter is constantly monitoring the grid AC voltage and frequency. 

If the voltage or frequency become too high or low, the inverter will throw an alarm.


OV-G-V = over-grid voltage detected

UN-G-V = under-grid voltage detected

OV-G-F = over-grid frequency detected

UN-G-V = under-grid frequency detected


Troubleshooting Steps:

Step 1: Depending on the alarm, use a multimeter to check the AC grid voltage/frequency. Record this value. If the value is constantly very low or very high then the utility company should be notified.

Step 2: Identify which grid profile is being used. Make sure it is UL-240V-18 or R21P3-24A. Change it if it is not.

Step 3: Determine which of the above four alarm types are recurring. This will tell you which grid profile parameter to adjust.

Step 4: On SolisCloud, modify the grid trip setting (explained below)

Step 5: Wait five to ten minutes to see if the alarms clear

Step 6: If the alarms do not clear, try adjusting the Riso limit (explained below)

Step 7: If after adjusting the Riso limit the alarms still persist, call Solis Support (866)438-8408

Step 8: Solis Support will push the latest firmware to the inverter remotely

Step 9: After the update, monitor the system for another ten minutes to see if the alarms clear

Step 10: If the alarms do not clear, Solis Support should escalate the issue internally


What determines when these alarms get thrown are the grid profile trip settings. 

These settings can be found by:

1. Go to the inverter details page on SolisCloud

2. Click on Inverter Control, then click Grid Code Parameters. 

3. Set the Grid Standard Precision by clicking Read, selecting Voltage 0.1V, Time 0.01s, Frequency 0.01Hz, then clicking Save. 

4. Click the Batch Read button at the bottom of the page.



The standard Grid Code (Profile) is UL-240V-18, be sure that the inverter is set to this. The other viable profile is R21P3-24A, which is for Rule 21. Either profile can be selected, but if the inverter is on any other profile please change it by selecting the profile in the Grid Code Set Value drop down menu. Then click Save.


If the inverter is throwing constant and persistent alarms of the same type (example: OV-G-V01), then it is allowed to increase the upper voltage trip settings. This should stop any nuisance tripping from occurring. However, please keep in mind that the inverter is not the cause of the alarms, it is giving alarms due to what it sees on the grid side. 


To change the grid profile trip point, follow these steps:


1. Click Read in the Set Value column for the parameter

2. Enter in a new value into the Set Value field

3. Click Save

4. Click Read again to make sure the parameter stayed saved

5. If the parameter did not stay saved, then increase it or lower it because it was too far out of the possible range

6. Try saving a different value until you get one that remains saved.


Once the trip point has been changed, monitor the system to make sure the alarms clear and the system goes into normal operation. If it does not, then there is one more thing you can try.


Go to Advanced Setting then to Special Function Setting 3. Look for the bottom-most setting “RisoLim” click Read to pull the current value, it should be 200K. Enter 80 into the Set Value box where it says “Input” and then click Save. 

Wait another 10 minutes to see if the alarms clear. If they do not, contact Solis Support (866)438-8408 to have them check if there is a newer firmware version. 



Was this article helpful?

That’s Great!

Thank you for your feedback

Sorry! We couldn't be helpful

Thank you for your feedback

Let us know how can we improve this article!

Select at least one of the reasons
CAPTCHA verification is required.

Feedback sent

We appreciate your effort and will try to fix the article