ABB Circuit Shield 87B User Manual

High
-
Impedance
Differential
Relays
IB
7.6
.
1.7
-
7
Page
11
TESTING
1
.
MAINTENANCE
AND
RENEWAL
PARTS
No
routine
maintenance
is
required
on
these
relays
.
Follow
test
instructions
to
verily
that
the
relay
is
in
proper
working
order
.
We
recommend
that
an
inoperative
relay
be
returned
to
the
factory
for
repair
;
however
,
a
schematic
diagram
is
available
on
request
for
those
who
wish
to
attempt
repairs
.
Metal
handles
provide
leverage
to
withdraw
the
relay
assembly
from
the
case
.
Removing
or
installing
a
drawout
unit
with
the
relay
in
service
will
not
cause
an
undesired
operation
.
The
assembly
is
identified
by
the
catalog
number
on
the
front
panel
and
a
serial
number
stamped
on
the
bottom
of
the
board
.
Should
separation
of
the
upper
and
lower
circuit
boards
be
necessary
,
remove
(
2
)
screws
that
attach
the
left
and
right
handle
assemblies
to
the
upper
printed
circuit
board
,
and
remove
(
2
)
screws
that
attach
the
bottom
circuit
board
to
the
bracket
on
the
back
plane
board
.
The
lower
board
may
then
be
withdrawn
forward
from
the
printed
circuit
connector
.
An
18
point
extender
board
is
available
from
the
factory
if
access
to
the
lower
circuit
board
is
required
during
testing
or
troubleshooting
.
A
test
plug
assembly
,
catalog
number
400
X
0001
is
available
for
use
with
the
419
B
series
units
.
This
device
plugs
into
the
relay
case
on
the
switchboard
and
allows
access
to
all
external
circuits
wired
to
the
case
.
See
Instruction
Book
IB
7.7
.
1.7
-
8
for
details
on
the
use
of
this
device
.
Also
see
note
on
page
13
.
2
.
HIGH
POTENTIAL
TESTS
High
voltage
insulation
tests
are
not
recommended
for
the
relay
circuits
.
The
relay
has
been
tested
at
the
factory
.
If
a
control
wiring
insulation
test
is
required
,
remove
the
drawout
assembly
from
the
case
before
applying
test
voltage
.
(
Partial
withdrawal
to
break
all
connectors
is
sufficient
)
.
3
.
ACCEPTANCE
TESTS
Relays
are
subjected
to
factory
tests
and
calibration
in
accordance
with
established
procedures
.
Problems
with
differential
relay
systems
are
often
attributed
to
improper
connections
of
current
transformers
and
associated
circuitry
.
IF
PROBLEMS
ARE
EXPERIENCED
ON
INITIAL
START
-
UP
.
BE
SURE
TO
CHECK
CT
WIRING
FOR
PROPER
POLARITY
AND
RATIO
OF
ALL
CURRENT
TRANSFORMERS
.
TEST
ONE
RELAY
AT
TIME
,
A
.
Operational
-
Acceptance
Test
.
Push
-
To
-
Test
Button
Tests
should
be
made
on
a
de
-
energized
main
circuit
.
If
tests
are
to
be
made
on
an
energized
circuit
,
be
sure
to
take
all
necessary
precautions
.
When
the
test
button
is
depressed
,
a
fault
condition
is
simulated
and
the
relay
'
s
output
will
operate
to
trip
the
lockout
relay
and
associated
breakers
.
It
is
normal
during
this
operational
test
,
that
the
output
relay
will
continuously
open
and
close
(
operate
,
reset
)
as
long
as
the
test
button
is
depressed
.
At
the
same
time
,
the
target
will
drop
to
indicate
operation
.
This
simple
test
is
often
all
that
is
required
to
verify
that
the
relay
is
operational
.
Courtesy of NationalSwitchgear.com

ABB Circuit Shield 87B Specifications

General

Brand	ABB
Model	Circuit Shield 87B
Category	Relays
Language	English