4.1.1.2
TT system
Overview
7UDQVIRUPHURU
JHQHUDWRU
7RWKHV\VWHP
([DPSOH 7UDQVIHURI1JURXQGHGQHXWUDO
SRLQW
/
/
/
1
3(
Figure 4-2
TT system
In a TT system, the transformer grounding and the installation grounding are independent of
one another.
There are TT supplies where the neutral conductor N is either transferred – or not.
Function description
Note
Operation in IEC or UL systems
For installations in compliance with IEC, operation on TT systems is permissible. For
installations in compliance with UL, operation on TT systems is not permissible.
Table 4-2
Converter operated on a TT system
Converter
Line supply with grounded neutral
Line supply with grounded phase conduc‐
tor and a voltage ≤ 600 V phase to phase
Frame size
A
B
C
D
E
F
G
H
J
A
B
C
D
E
F
G
H
J
Without line
filter
✓
✓
✓
✓
✓
✓
○
○
○
✓
✓
✓
✓
✓
✓
○
○
○
Integrated
line filter C2
✓
✓
✓
✓
✓
✓
✓
○
○
-
-
-
-
-
-
✓
1)
○
○
Integrated
line filter C3
○
○
○
○
○
✓
✓
✓
✓
○
○
○
○
○
-
✓
1)
✓
1)
✓
1)
✓ = Operation permissible
✓
1)
Operation permissible once grounding screw has been removed
If the grounding screw has been removed, the converter no longer fulfills the requirements of class C3.
- Operation not permissible
○ Converter not available
More information on removing the grounding connection in the converter:
Removing functional grounding of the converter (Page 78)
Wiring
4.1 Line supply and motor
SINAMICS G120X converter
Operating Instructions, 06/2019, FW V1.01, A5E44751209B AC
77
