ABB Circuit Shield 87B User Manual

High
-
Impedance
Differential
Relays
IB
7.6
.
1.7
-
7
Page
2
TABLE
OF
CONTENTS
Page
2
Page
2
Page
3
Page
6
Page
11
Page
14
Introduction
Precautions
Placing
Relay
into
Service
Application
Data
Testing
.
.
.
.
Obsolete
Models
INTRODUCTION
These
instructions
contain
the
information
required
to
properly
install
,
operate
and
test
the
ABB
Type
87
B
high
-
impedance
single
phase
differential
relay
.
The
Type
87
B
relay
is
a
high
-
speed
or
instantaneous
differential
voltage
device
intended
primarily
for
bus
differential
protection
.
High
current
sensitivity
also
allows
the
relay
to
be
used
for
differential
protection
of
resistance
grounded
systems
and
machines
or
reactors
.
The
relay
contains
voltage
-
limiting
resistors
(
varistors
)
which
limit
voltage
across
its
input
terminals
to
a
safe
value
during
system
faults
.
The
relay
is
housed
in
a
case
suitable
for
conventional
semi
-
flush
panel
mounting
.
The
unit
offers
totally
drawout
construction
with
integral
test
facilities
.
Current
transformer
shorting
is
accomplished
by
a
direct
-
acting
spring
and
blade
assembly
upon
removal
of
the
relay
from
its
case
.
Sequenced
disconnects
eliminate
any
possibility
of
nuisance
tripping
during
withdrawal
or
insertion
of
the
relay
.
A
target
indicator
is
mounted
on
the
front
panel
.
The
target
is
reset
by
means
of
a
pushbutton
extending
through
the
relay
cover
.
Control
voltage
must
be
present
to
reset
the
target
.
Earlier
models
,
catalog
series
219
B
are
covered
in
IB
7.6
.
1.7
-
5
.
PRECAUTIONS
The
following
precautions
should
be
taken
when
applying
these
relays
:
1
.
Incorrect
wiring
may
result
in
damage
.
Be
sure
wiring
agrees
with
the
connection
diagram
for
the
particular
relay
before
the
relay
is
energized
.
Be
sure
control
power
is
applied
in
the
correct
polarity
before
applying
.
2
.
Apply
only
the
rated
control
voltage
marked
on
the
relay
front
panel
.
The
proper
polarity
must
be
observed
when
the
DC
control
power
connections
are
made
.
3
.
Do
not
apply
high
voltage
tests
to
solid
state
relays
.
If
a
control
wiring
insulation
test
is
required
,
withdraw
the
relay
from
the
case
before
applying
test
voltage
.
4
.
A
lockout
relay
(
e
.
g
.
type
LOR
,
HEA
,
or
WL
)
must
be
used
to
short
circuit
the
input
signal
side
of
relay
87
B
upon
operation
of
the
differential
circuit
due
to
faults
within
the
protected
zone
.
5
.
The
entire
circuit
assembly
of
the
relay
is
removable
.
The
unit
should
insert
smoothly
.
Do
not
use
excessive
force
.
6
.
Follow
test
instructions
to
verify
that
relay
is
in
proper
working
order
.
If
a
relay
is
found
to
be
inoperative
,
return
to
factory
for
repair
.
Immediate
replacement
of
the
relay
can
be
made
available
from
the
factory
;
identify
by
catalog
and
serial
numbers
.
We
suggest
that
a
complete
spare
relay
be
ordered
as
a
replacement
,
and
the
inoperative
unit
be
repaired
and
retained
as
a
spare
.
7
.
CAUTION
:
Since
troubleshooting
entails
working
with
energized
equipment
,
caution
should
be
taken
to
avoid
personal
shock
.
Only
competent
technicians
familiar
with
good
safety
practices
should
services
these
devices
.
Courtesy of NationalSwitchgear.com

ABB Circuit Shield 87B Specifications

General

Brand	ABB
Model	Circuit Shield 87B
Category	Relays
Language	English