Siemens 7SR210 - 2.8 High Impedance Restricted Earth Fault Protection (64 H)

7SR21 & 7SR22 - Installation Guide
7.4 Typical Connection: 7SR22 Directional OC/EF and NVD
V
L
V
N
L1 L2 L3
3Vo
S1
S2
P1
P2
I
L1
(I
A
)
1
2
5
6
9
10
13
14
A
17
18
19
20
21
22
23
24
25
26
27
28
1A
5A
1A
5A
1A
5A
1A
5A
15
16
11
12
1A
5A
3
4
7
8
B
C
V
4
(V
X
)
V
L3
(V
C
)
V
L2
(V
B
)
V
L1
(V
A
)
I
L2
(I
B
)
I
L3
(I
C
)
I
4
(I
G
)
I
5
(I
SEF
)
NOTES
1) CT circuits are shown connected to 1A tap – use alternative tap for 5A rated CTs.
2) CT and Earth connections are typical only.
3) Voltage Config:-V
ab
, V
bc
, 3V
0
Figure 7.4-1 7SR22 Applied to Feeder
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