Siemens 7UT51

6 Bus Differential Protection (87B)
7UT51 v3
82 PRIM-2330C
Figure 6.1 Typical CT Wiring for a Bus with Two Branches
Figure 6.2 Typical CT Wiring for a Bus with Three Branches
7UT51 Relay
A
B
C
Branch 1
I
A
I
B
I
C
I
a
I
b
I
c
3A1 3A2
2A1
2A2
1A1
1A2
3B1
3B2
2B1
2B2
1B1
1B2
A
B
C
Branch 2
Branch 1
Branch 2
7UT513
A
A
B
B
C
C
I
A
I
B
I
C
3A1
3A2
2A1
2A2
1A1
1A2
3B1
3B2
2B1
2B2
1B1
1B2
3D1
3D2
2C1
2C2
1C1
1C2
I
a
I
b
I
c
I
a’
I
b’
I
c’
Branch 3
A
B
C