Schweitzer Engineering Laboratories SEL-787-2 - Page 31

Schweitzer Engineering Laboratories, Inc. SEL-787-2, -3, -4 Data Sheet
31
Figure 45 SEL-787-4X Provides 3-Winding Transformer Differential Protection, REF Protection, Overcurrent
Protection, and Fan Bank Control With LTC Monitoring
SEL-787-4X Relay
52-4
52-1
A2 (H1)
B2 (H2)
C2 (H3)
a (T1)
b (T2)
c (T3)
Fiber Port
SEL-2600
N
L
E01
E03
E04
E06
E08
E05
E07
E09
E10
E12
E02
A2 B2
C2
Z01
Z02
Z03
Z04
Z05
Z06
52-2
Z07
Z08
Z09
Z10
Z11
Z12
IAW3
IBW3
ICW3
IAW4
IBW4
ICW4
IAW1
IBW1
ICW1
IAW2
IBW2
ICW2
RTDs
E11
Ambient
Temp
Top Oil
Temp
LTC
Note: The CT secondary circuit should be grounded in the relay cabinet.
2000/5 A
13.8 kV
30 MVA
69 kV
200/5 A
IBW3
IAW3
A1 B1 C1
400/5 A
a b c
A1 (X1)
B1 (X2)
C1 (X3)
138 kV
T3
T2
T1
X3
X2
X1
H3
H2
H1