IT mains: is an isolating transformer mandatory?

[_ctrlX_TSA]

I have a configuration with XCS + XMS drives.

Reading the project planning, in the Mains voltage table of an XCS in seems that the drive can be connected directly to IT mains.

But then also in the manual is written : "To operate the drive system at an IT mains type, electrically decouple the drive
system including mains filter and mains choke via an isolating transformer."

So, with IT mains, is an isolating transformer mandatory or not?

[Drives_Uwe · Accepted solution]

It is not mandatory but a high recommendation from our side, see: