Inverter Troubleshooting, Grid Fault, Too high voltage

[TheWorm3]

Hi everyone,
I'm new to this site and wanted to reach out for a bit of help. We installed a 15 kW system recently and have been having issues getting it up and running. We've narrowed the issue down to getting too much AC voltage from the grid. The problem however, is that line voltage reads any from 247-252 Vac, but once the inverters (2 SolarEdge-7600s) turn on, the Vac spikes to 260-264 until the error code 29 and 33 show on the inverter screen. Has anybody encountered this before or can anyone offer any information that may help? Thank you in advance!

[bcroe]

That is a pretty good description of what happened here when the PoCo raised the line voltage. The most straight forward fix is
to get them to lower it. Check to see how much higher the voltage is at the inverters, than at the meter. If the inverters are 5 or 10
volts higher, using heavier wire will help bring it down. Failing that, perhaps your inverters can be programed for a higher alarm
point voltage. The very last ditch method is an auto transformer to knock a few volts off what the inverters see, you don't really
want to go there, but I almost did. Bruce Roe

[jflorey2]

Has anybody encountered this before or can anyone offer any information that may help? Thank you in advance!

To echo what BC said you have a few options:
-If the voltage rise is due the wiring between your inverter and meter, heavier gauge wire may help.
-Getting the utility to lower the voltage is sometimes an option.
-Seeing if you can change the voltage setpoints at the inverter. You are right on the edge so it may only require a change of a few volts to make the difference.

I had this problem with an early Trace Suntie installation. The inverters were very sensitive and I was allowing too much voltage rise between the inverter and the main panel.