Overvoltage on AC out

Hi guys,

“ MultiPlus-II 48/5000/70-50
Alarm #5 Overvoltage on AC-out “

I’ve had this error code come up on a job.

It’s happened a few times early on but hasn’t been an issue since.

Customer reported it happened 3 times in the last 12hours.

I believe it’s when the generator has been running. This morning they lost power because of it whilst generator was on.

The system has 3 x 5kva multiplus with 2 x fronius primos and a rs450/200

Any help is appreciated.