It System - Siemens SINAMICS G120 Operating Instructions Manual

Installing
4.4 Connecting the line supply and motor
4.4.1.3

IT system

In an IT line system, all of the conductors are
insulated with respect to the PE protective
conductor – or connected to the PE protective
conductor through an impedance.
There are IT systems with and without transfer
of the neutral conductor N.
Note
Behavior of the inverter when a ground fault occurs
If the inverter is to remain operable even when a ground fault occurs at the inverter output,
you must install an output reactor. This prevents an overcurrent trip or damage to the drive.
Inverter connected to an IT system
● Inverters with integrated line filter:
– Operation on IT line systems not permissible.
● Inverter without line filter:
– Operation on all IT line systems permissible.
Note
690 V inverters: Output reactors for frame sizes FSD and FSE
An output reactor is required for 690 V reactors in frame sizes FSD and FSE.
76
Note
Special feature of FSG inverters
FSG inverters with integrated C3 line filter can be operated in IT line systems if you
remove the screw for functional grounding.
Figure 4-7 Remove screw for functional grounding (Page 73)
If you remove the screw for functional grounding, the EMC properties deteriorate and
the requirements of Class C3 are no longer met.
Converter with the CU250S-2 Control Units
Operating Instructions, 04/2018, FW V4.7 SP10, A5E31759476B AG