ABB REF 542plus - Page 18

Feeder Terminal REF 542plus
1MRS756269
Typical connection dia-
grams (cont´d)
18
The schematic diagram below shows a con-
nection for a power transformer feeder with
differential, earth-fault and restricted earth-
fault protections.
The used analog input board has 8 inputs for
currents. Channels 1 -6 are for the differential
protection, channel 7 is used for the restricted
earth-fault protection and channel 8 for the
earth-fault protection.
A051283
Fig. 11 Power transformer differential protection
TI/L1
TI/L1
TI/L2
TI/L2
TI/L3
TI/L3
L1
L2
L3
Q1
S1
S1
S1
S1
S1
S1
S1
S2
S2
S2
S2
S2
S2
S2
11
22
10
21
5
23
24
12
7
18
6
13
9
15
20
8
3
14
2
17
1
19
18
4
X80
AI1
AI2
AI3
AI4
AI5
AI6
AI7
AI8