ABB Circuit Shield 87B - Page 13

High
-
Impedance
Differential
Relays
IB
7.6
.
1
.
7
-
7
Page
13
T E S T
S W I T C H
VASIA
SCC
AUTO
-
TRANSFORMER
S
7
S
ecT
*
L
F
use
<
+
>
rH
—
*
HLJ
O
70
o
I
1
1
l
I
•
•
o
1
SAT
OC
4
AO
V
MAX
120
VAC
V
M
CONTROL
A
SAT
M
STEP
UP
TRANSFORMER
e
O
®
o
o
(
-
)
Figure
4
:
Test
circuit
-
bench
tests
of
drawout unit
Note
on
the
use
of
the
MT
-
XC
Test
Plug
-
Catalog
No
.
400
X
0001
When
using
the
test
plug
in
the
Type
87
B
relay
case
,
access
to
the
external
CT
circuit is
obtained
at
any
of
the three
current
circuit
shorting
switches
.
In
other
words
,
the
CT
shorting
switches
are
in
series
in
the
CT
secondary
circuit
.
Courtesy of NationalSwitchgear.com