Schweitzer Engineering Laboratories SEL-787-2 - Page 32

SEL-787-2, -3, -4 Data Sheet Schweitzer Engineering Laboratories, Inc.
32
Figure 46 SEL-787-3E Provides Auto-Transformer Differential Protection, REF Protection, Overcurrent Protection,
and Voltage-Based Protection
52-1
a
b
c
52-3
A
B
C
SEL-787-3E Relay
IAW3
IBW3
ICW3
IN
IBW2
ICW2
Delta
Tertiary
E01
E02
E03
E04
E05
E06
E07
E08
Z09
Z10
Z11
Z12
52-2
a
b
c
Z01
Z02
Z03
Z04
Z05
Z06
IAW1
IBW1
ICW1
Z08
Z07
IAW2
A (H1)
B (H2)
C (H3)
a (X1)
c (X3)
b (X2)
Note: The CT secondary circuit should be grounded in the relay cabinet.
E12
E10
E09
E11
VN
VC
VB
VA
150/5 A
230 kV
50 MVA
138 kV
250/5 A
138 kV
250/5 A
H3H2H1
X3X2X1