Smc flex

Hey guys
We have an smc flex that faulted. Fault 14. Went through the troubleshooting guide ended up swapping the connections on the back of the controller to see if the fault rolled with the phase change when starting the circuit we had another smc flex fault with the same code just another phase. Tried starting again no fault on the second drive but the first drive faulted again different phase. We are thinking maybe incoming power our voltage hit as low as 290v when starting up on one phase. Any suggestions on where to go from here?

Update

Ended up the contacts on one of the phases was welded closed our other soft start is about to do the same didn’t have a spare ended up cleaning up the contact ran fine all night.