Siemens PM240-2 Hardware Installation Manual page 39

TT line system
In a TT line system, the transformer grounding and the installation grounding are
independent of one another.
There are TT systems with and without transfer of the neutral conductor N.
Inverter operated on a TT line system
● Inverter with integrated or external line filter:
– Operation on TT line systems with grounded neutral point permissible.
– Operation on TT line systems without grounded neutral point not permissible.
● Inverter without line filter:
– Operation on all TT line systems permissible.
● For installations in compliance with IEC, operation on a TT line system is permissible. For
installations in compliance with UL, operation on a TT line system is not permissible.
Examples for inverters connected to a TT line system
Figure 5-2
Power Module PM240-2
Hardware Installation Manual, 12/2015, A5E33294624B AD
TT line system with neutral conductor N and with grounded neutral point
Connecting-up
5.1 Line and motor connection
39