ABB Circuit Shield 87B User Manual

High
-
Impedance
Differential
Relays
IB
7.6
.
1.7
-
7
Page
3
PLACING
THE
RELAY
INTO
SERVICE
L
RECEIVING
.
HANDLING
^
STORAGE
Upon
receipt
of
the
relay
(
when
not
included
as
part
of
a
switchboard
)
examine
for
shipping damage
.
If
damage
or
loss is
evident
,
file
a
claim
at
once
and
promptly
notify
Asea
Brown
Boveri
.
Use
normal
care
in
handling
to
avoid mechanical
damage
.
Keep
the
relay
clean and
dry
.
2
.
INSTALLATION
Mounting
:
The
outline
dimensions and
panel
drilling
and
cutout
information
is
given
in
Figure
1
.
Terminal
and
basic circuit identification
will be found
in
Figure
2
.
Connections
:
A
typical
external
connection
diagram
showing
(
3
)
Type
87
B
relays
used
for
bus differential
protection
is shown
in
Figure
3
.
Wiring
and interconnections should be
in
accordance
with instructions
.
Current
transformer
polarities
MUST
be
as
shown
.
The
relays
have metal
front
panels
which
are
connected
through
printed
circuit
board
runs
and
connector
wiring
to
a
terminal
at
the
rear
of
the
relay
case
.
The terminal is marked
“
G
”
.
In
all
applications
this terminal should be wired
to
ground
.
A
lockout
relay
must
be
wired
as
shown
in
Figure
3
.
DC
must
be
connected
in
the
proper
polarity
as
shown
in
the
diagram
.
To
obtain best sensitivities and facilitate
lower
pickup
settings
,
the
junction
points
of
CT
leads
should he made
equidistant
from
all
CT
'
s
,
or
leads
of
equal
resistance
provided
.
3
.
SETTINGS
VOLTAGE
PICKUP
:
75
-
400
Volts
AC RMS
,
settable
by
means
of
a
front
panel
switch
at
75
,
100
,
150
,
200
,
250
,
300
,
350
or
400
volts
.
TEST
FEATURE
:
A
built
-
in
test
push
button
is
provided
for
operational
trip
tests
and
mounted
behind the
removable
front
cover
.
When
using
the built
-
in
test
switch
,
release the button
as
soon as
the
87
B
operates
.
If
the button is held
in
,
the
relay
will
continually
repeat
its
trip
and
reset
functions
rapidly
,
and will
appear
to
chatter
.
RESET
:
The
relay
does
not
require
manual
reset
as
it
restores
itself
to
functional
status
upon
clearing
of
the faults and
resetting
of
the
lockout
relay
.
The
operation
indicator
is
of
the
memory
type
and
can
be
reset
after
a
fault
or
test
without
front
cover
removal
.
Courtesy of NationalSwitchgear.com

ABB Circuit Shield 87B Specifications

General

Brand	ABB
Model	Circuit Shield 87B
Category	Relays
Language	English