OV-G-V Alarm

Created by Victor Herrera, Modified on Mon, Jan 12 at 10:59 AM by Adriana Rivas

An OV G V alarm on a Solis inverter refers to an Over Grid Voltage issue. This means that the grid voltage exceeds the acceptable limits set by the inverter. Here's a step-by-step guide to troubleshoot the issue:

OV-G-V 01	Grid voltage is higher than standard code's 1st level overvoltage limit for the set period of time
OV-G-V 02	Grid Voltage transient value is over 1.35 times of rated voltage peak value
OV-G-V 03	Grid voltage is higher than the 10 min overvoltage limit in the standard code
OV-G-V 04	Grid voltage is higher than the standard code's 2nd level overvoltage limit for the set period of time

Possible causes

Grid code/standard not set properly.

The primary cause of the error is the grid code being set improperly. Typically, this happens at the factory during the unit’s "burn" in period. They are programmed with a specific grid code for the burn-in process, right before they are shipped out the grid code is changed to their country of origin's grid standard.

Inverter measurement device out of tolerance

The inverter's internal voltage measurement system is not accurately reading the AC voltage from the grid. This unit will need to have an RMA. You can test this out by using a meter to read the AC voltages and comparing them to the voltages on the inverter's LCD. If there is a difference, particularly in one phase, then the inverter will need to be replaced.

Bad transformer downstream

Due to an issue with the transformer providing power to a home or facility, the voltage may appear TOO high or TOO low, the transformer's taps will need to be adjusted to provide the proper output to the inverter. The inverter is doing its job of notifying the customer that there is a problem with the grid voltage being too low or too high. This is not an internal fault on the inverters part; it will need to be diagnosed with the equipment on site.

Undersized wire

Line loss can cause voltages to spike leading to an OV-G error. This happens when the line loss causes excess resistance to build up in the AC circuit, the inverter attempts to compensate for this by increasing the voltage to drive the current. When the AC voltage exceeds the inverter's limit it causes a shut down. Once production stops the inverter will see the grid voltage decrease, so it will attempt to restart. This will continue to happen in a cycle throughout the day. It can be seen on monitoring platforms as multiple faults every day. Lowing the transformer taps or increasing the conductor size is the solution. Alternatively, the inverter's internal set points can be adjusted with the permission of the utility or facility owner.

Loose AC Connections

Any loose AC connections can also cause grid voltage spikes. When resistance is introduced into the line heat and excess voltage issues can happen. Check all AC connections.

Troubleshooting

Confirm the correct grid standard has been set. If the incorrect is set, change to the right one and give the inverter some time to see if alarm clears.

On the LCD proceed to the ADVANCED SETTING section. Enter the password 0010. Select “Turn Grid off or on”. Select off. Choose SELECT STANDARD select UL-240V-A, UL-208V-A, UL-240V, UL-240V. hit ENTER to confirm the setting. Go back to Select “Turn Grid off or on”. Select on. Wait 5 minutes and the alarm should clear.

US Grid Code Meaning

UL-240V-A - AFCI ENABLED - Split Phase

UL-208V-A - AFCI ENABLED - Single Phase

UL-240V - AFCI DISABLED - Split Phase

UL-208V - AFCI DISABLED - Single Phase

If the correct grid standard is set and alarm keeps active. Ask tech to measure voltages on AC and DC and to take pictures if able.
If the AC voltage is high according to the voltmeter, advise tech about the high voltage on site and advise to contact the utility. If the issue is related to the grid customer can try to adjust upper limit with the permission of the utility.
If the AC voltage according to the voltmeter is within range, check the AC voltages according to the inverter’s LCD and compare the readings.
If there is a difference between readings, you may try to do an off set. This can only be done if the difference between the meter and the inverter’s LCD is -/+ 5 volts.
If an off set is done, power cycle the inverter.
If alarm does not clear or the off set can’t be done due to the difference between meter and inverter’s LCD being more than +/- 5 V.
Try a “restore settings”
If alarm is still not clear, make sure to get inverter’s firmware version and compare it with other inverters on site if any.
Make sure to get all basic pictures: nameplate, open wirebox, general installation, display showing the active alarm, pictures of voltages from the voltmeter and inverter’s LCD.
Check with L2 the possibility of a firmware update could fix the issue