Schweitzer Engineering Laboratories SEL-787-2 Manual page 32

32
Delta
Tertiary
B (H2)
b (X2)
A (H1)
a (X1)
c (X3)
C (H3)
Note: The CT secondary circuit should be grounded in the relay cabinet.
Figure 46 SEL-787-3E Provides Auto-Transformer Differential Protection, REF Protection, Overcurrent Protection,
and Voltage-Based Protection
SEL-787-2, -3, -4 Data Sheet
A
B C
150/5 A
52-3
230 kV
H1 H2 H3
X1 X2 X3
50 MVA
52-1
138 kV
250/5 A
a b
52-2
138 kV
250/5 A
a b
c
c
E01
IAW3
E02
E03
IBW3
E04
E05
ICW3
E06
E07
IN
E08
Z01
IAW1
Z02
Z03
IBW1
Z04
Z05
ICW1
Z06
Z07
IAW2
Z08
Z09
IBW2
Z10
Z11
ICW2
Z12
SEL-787-3E Relay
Schweitzer Engineering Laboratories, Inc.