Siemens SINAMICS S120 Manual page 104

Electrical installation
4.6 Connections
Active Line Modules
If the device is operated on an ungrounded / IT system, the connection clip for the basic
interference suppression module of the Active Interface Modules (-A2) must be removed.
Figure 4-19
102
Removing the connection clip to the basic interference suppression module in the Active
Interface Module, frame size FX
Cabinet Modules
Manual, 03/2013, A5E03263538A