Siemens SINAMICS S120 Manual page 90

Electrical installation
4.5 Connections
Basic Line Connection Modules
If the device is operated on a non-grounded system (IT system), the connection clip to the
basic interference suppression module must be removed.
Figure 4-7
90
Remove the connecting clip to the basic interference suppression module in the Basic
Line Connection Module
Cabinet Modules liquid cooled
Manual, 10/2015, A5E37067587A