ABB SPAJ 111 C User Manual page 12

Example 2.
Earth-fault protec-
tion in resistively
earthed network
12
1)
BS
25 26 27
10 11
SGR/1
U3
SPAJ 111 C
1) Blocking signal from the earth-fault relay of an outgoing feeder
Fig. 5. The sensitive non-directional earth-fault relay SPAJ 111 C used as the earth-fault protection
for the infeeder cubicle and the busbars. The selector switch settings are shown in the table on the
following page.
I
I
II
+ (~)
Uaux
(~)
-
IRF START2
61 62 70 71 72 73 74 75
≅
_
E
+ -
U3
IRF
t >
Io>
SGB
4
5
t >>
Io>>
I/O
U1
-
0
-
I
+
0
+
I
+
0
START1 SIGNAL1 TRIP2
+
77 78 80 81 68 69
F D C
1 1
SGR 3 2 4 7 5
SS1
TS1
SS2
TS2
-
0
- I
Rx Tx
+
TRIP1
+
SERIAL
PORT
65 66
B A
1 1
8 6
U2