Our data center provider just confirmed, that they have successfully completed the switch back to utility power for our FRA1.1. The faulty transformer has been replaced by an extra temporary generator, which serves as the power supply for the infrastructure load. This brings gridscale back to N+2 redundancy. The incident is now closed.
Stability has been maintained throughout the whole incident with no interruptions.
Please don't hesitate to get back to us, if there are any question.