ABB CIRCUIT SHIELD 87T - Page 17

Transformer
Differential
Relay
IB
7.6
.
1.7
-
4
Page
17
TEST
SET
Contact
Monitor
O
a
Figure
8
:
Typical
Test
Connections
a
Current
Source
#
1
II
60
HZ
Phase
=
o
deg
O
r
Minimum
Operating
Current
and
Pet
Differential
Characteristic
Tests
.
O
Current
Source
#
2
12
60
Hz
Phase
-
o
deg
a
Connection
shown
dotted
optional
depending
on
test
set
.
(
+
)
i
(
-
)
o
7
6
'
8
o
o
13
14
13
)
16
12
11
9
Note
:
use
50
Hz
sources
if
relay
has
50
Hz
nameplate
rating
.
Apply
dc
control
power
per
relay
’
s
nameplate
rating
.
Resistor
required
between
terminals
9
and
10
.
See
page
14
.
TEST
SET
Contact
Monitor
O
o
+
o
Current
Source
#
I
60
HZ
O
Figure
9
:
Typical
Test
Connections
Alternate
Method
for
Pet
Differential
CharacteriStic
Test
(
+
)
87
T
i
(
-
)
8
^
7
6
6
i
o
o
13
14
13
o
16
12
11
10
9
Courtesy of NationalSwitchgear.com