ABB Circuit Shield 87B User Manual

IB
7.6
.
1.7
-
7
Page
12
High
-
Impedance
Differential
Relays
B
.
Bench
Tests
-
Acceptance
or
Calibration
CAUTION
:
Since
testing
entails
working
with
energized
equipment
,
caution
should
be
taken
to
avoid
personal
shock
.
Only
competent
technicians
familiar
with
good
safety
practices
should
service
these
devices
.
Test
connections
are
readily
made
to
the
drawout
relay
unit
by
means
of
standard
banana
plugs
.
Current
input
connections
are
made
to
the
vertical
posts
at
the
blade
assemblies
.
Control
power
and
output
connections
are
made
at
the
rear
vertical
printed
circuit
board
.
This
rear
board
is
marked
for
easier
identification
of
the
connection
points
.
A
typical
test
circuit
is
shown
in
Figure
4
.
NOTE
:
A
fast
lockout
relay
(
e
.
g
.
type
HEA
or
LOR
)
must
be
used
during
bench
testing
to
protect
the
relay
from
the
damage
that
might
occur
due
to
errors
in
signal
application
.
If
operating
time
tests
are
conducted
,
certain
allowances
should
be
made
for
variations
in
the
trip
time
of
lockout
relays
or
readings
should
be
averaged
.
Regulation
or
voltage
drop
of
the
signal
source
should
be
taken
into
account
during
measurements
of
the
pickup
or
trip
time
.
Bench
tests
with
high
voltage
and
high
current
applied
to
the
relay
input
from
a
high
power
voltage
source
are
not
recommended
due
to
uncontrolled
energy
output
.
If
such
tests
are
contemplated
,
the
test
circuit
should
contain
properly
selected
current
transformers
of
allowable
ratio
and
saturation
voltage
,
and
a
lockout
relay
interconnected
as
in
the
contemplated
differential
scheme
.
1
.
Connect
relay
drawout
assembly
as
shown
in
Figure
4
.
Apply
proper
DC
control
voltage
per
relay
rating
.
2
.
Increase
test
voltage
gradually
until
the
87
B
relay
operates
.
NOTE
:
The
output
relay
will
continuously
open
and
close
(
operate
,
reset
)
during
this
test
,
however
,
not
during
actual
in
-
service
trips
since
the
associated
circuit
breaker
will
open
causing
loss
of
system
voltage
to
the
87
B
input
circuit
.
Read
the
voltage
at
the
instant
of
operation
(
not
later
)
.
If
calibration
adjustment
is
desired
,
rotate
pickup
trimmer
on
the
upper
printed
circuit
board
.
NOTE
:
The
Type
87
B
relay
has
a
continuous
thermal
rating
of
150
VAC
RMS
.
Calibration
at
higher
voltages
should
be
conducted
within
a
short
period
of
time
with
3
-
5
minute
intervals
between
tests
to
allow
proper
cooling
.
Do
not
apply
test
voltages
in
excess
of
600
V
RMS
unless
the
power
input
is
limited
to
1500
Wsec
and
a
lockout
relay
operates
properly
to
self
-
protect
relay
87
B
.
3
.
Signal
application
time
can
be
reduced
and
a
better
readout
of
the
voltage
can
be
obtained
if
the
voltmeter
is
connected
as
shown
by
the
dotted
line
(
See
Figure
4
)
.
Preset
the
voltage
at
higher
than
pickup
value
and
close
the
external
switch
causing
the
relay
to
trip
.
Reduce
the
voltage
gradually
until
relay
87
B
does
not
trip
.
Read
the
voltage
and
remove
the
signal
at
once
.
Courtesy of NationalSwitchgear.com

ABB Circuit Shield 87B Specifications

General

Brand	ABB
Model	Circuit Shield 87B
Category	Relays
Language	English