ABB CIRCUIT SHIELD 87T - Page 19

Transformer
Differential
Relay
IB
7.6
.
1.7
-
4
Page
19
\
R
217
Percent
-
second
-
harmonic
calibration
potentiometer
R
228
R
230
S i
Q
O
U
203
R
229
l
Turn
R
217
clockwise
to
reduce the
percentage
of
second
harmonic
required
to
restrain
relay
operation
.
H
R
226
h
o
-
tzn
C
203
C
210
RZSk
t
—
I
R
219
R
227
in
R
217
"
+
i
Connect
jumper
between
pins
3
and
5
for
test
of
87
T
Instantaneous
Unit
80
S
•
T
C
211
•
CM
C
209
R
20
B
•
w
U
201
R
201
H
H
C
201
R
2
B
2
1
H
R
205
R
203
088
Typical
Layout
-
Type
87
T
Harmonic
Restraint
Module
Board
C
2
SB
Q
O
o
R
22
M
R
2
W
Type
87
T
Typical
Layout
Main
Lower
Circuit
Board
R
11
9
Instantaneous
Unit
Pickup
Calibration
Potentiometer
Turn
R
119
clockwise
to
increase
pickup
.
Courtesy of NationalSwitchgear.com