ABB RELION REX640 Technical Manual page 649

1MRS759142 C
REX640
Technical Manual
A B C
W1
W2
W3
GUID-5AA98439-77BC-4902-81B4-DF360AD3ECD2 V2 EN
Figure 356: Connection of current transformers of Type 1 and example of
currents during an external fault
A B C
W1
W2 W3
GUID-13923612-8050-48D9-AC3E-8455821A0DC5 V2 EN
Figure 357: Connection of current transformers of Type 2 and example of
currents during an external fault
Similar connections are done for a three-winding transformer.
If the rated primary current of the current transformers is not equal to the rated current
of the power transformer on a side of the transformer, setting parameters CT ratio Cor
A B
1/5A
A1
N
1/5A
B1
N
1/5A
C1
N
W1
W2
1/5A
A2
N
1/5A
B2
N
1/5A
C2
N
A B
1/5A
A1
N
1/5A
B1
N
1/5A
C1
N
W1
W2
1/5A
A2
N
1/5A
B2
N
1/5A
C2
N
Section 4
Protection functions
C
1/5A
N
1/5A
N
1/5A
N
W3
1/5A
N
1/5A
N
1/5A
N
C
1/5A
N
1/5A
N
1/5A
N
W3
1/5A
N
1/5A
N
1/5A
N
A1
B1
C1
A2
B2
C2
A1
B1
C1
A2
B2
C2
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