GE IACS1A User manual

GEK—34053G
TYPES
IACS1A
FORM
800
AND
UP
IACS1B
FORM
800
AND
UP
IACS2A
FORM
800
AND
UP
IAC52B
FORM
800
AND
UP
INSTRUCTIONS
TIME
OVERCURRENT
RELAYS
GENERAL
ELECTRIC

GEK-34053
TABLE
OF
CONTENTS
DESCRIPTION
APPLICATION
CONSTRUCTION
RATINGS
TIME-OVERCURRENT
UNIT
INSTANTANEOUS
UNIT
TARGET
AND
SEAL-IN
UNIT
.
CONTACTS
BURDENS
CHARACTERISTICS
RECEIVING,
HANDLING,
AND
STORAGE
ACCEPTANCE
TESTS
VISUAL
INSPECTION
MECHANICAL
INSPECTION
ELECTRICAL
TESTS
DRAWOUT
RELAYS,
GENERAL
POWER
REQUIREMENTS,
GENERAL
TIME-OVERCURRENT
UNIT
TIME
SETTING
PICKUP
TEST
TIME
TEST
INSTANTANEOUS
UNIT
SETTING
THE
INSTANTANEOUS
PICKUP
TEST
TARGET
AND
SEAL-IN
UNIT
PICKUP
AND
DROPOUT
TEST
INSTALLATION
TIME-OVERCURRENT
UNIT
TARGET
AND
SEAL-IN
UNIT
INSTANTANEOUS
UNIT
PERIODIC
CHECKS
AND
ROUTINE
TIME
OVERCURRENT
UNIT
INSTANTANEOUS
UNIT
TARGET
AND
SEAL—IN
UNIT
CONTACT
CLEANING
-
SYSTEM
TEST
SERVICING
TIME-OVERCURRENT
UNIT
PICKUP
TESTS
.
TIME
TESTS
INSTANTANEOUS
UNIT
TARGET
AND
SEAL-IN
UNIT
RENEWAL
PARTS
LIST
OF
FIGURES
(Cover
photo
8041316)
UNIT
MAINTENANCE
PAGE
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2

GEK-34053
TIME OVERCURRENT
RELAYS
DESCRIPTION
The
Type
IAC51
and
1AC52
relays
are
single—phase,
current—
operated,
AC
devices
with
inverse
time/current
characteristics.
They
are
utilized
to
protect
commercial,
industrial,
and
utility
power
distribution
systems
against
either
multi—phase
or
phase—to—ground
faults.
Each
relay
consists
of
a
basic
induction—disk
time—overcurrent
unit,
and
a
dual—rated
target/seal—in
unit,
and
may
include
a
hinge—
type
instantaneous—overcurrent
unit.
Both
the
time—overcurrent
unit
and
the
instantaneous
unit
are
adjustable
over a
range
of
about
8
to
1.
The
available
ranges
in
amperes
of
both
units,
as
well as
information
on
their
continuous
rating,
contact
rating,
and
target/seal—in unit
tap
ratings
are
given
in
the
section
on
RATINGS.
A
standard
Si
case
is
used to
mount
each
relay.
The
outline
and
mounting
dimensions
of
this
case
are
shown
in
Figure
12.
The
basic
differences
between
the
relays
covered
by
these
instructions
are
noted
in the following
table:
TYPE
INSTANTANEOUS CONTACT
INTERNAL
UNIT
CIRCUIT
CONNECTIONS
IACS1A
NO
1
FIGURE
4
IAC51B
YES
1
FIGURE
5
IAC52A
NO
2
FIGURE
6
IAC52B
YES
2
FIGURE
7
The.se
instructions
do
not
purport to
cover
all
details
or
variations
in
equipment
nor provide
for
every
possible
contingency
to
be
met
in
connection with
installation,
operation
or
maintenance.
Should
further
information
be desired
or
should
particular
problems
arise
which
are
not
covered
sufficiently
for
the
purchaser’s
purposes,
the
matter
should
be
referred
to
the
General
Electric
Company.
To
the
extent
required
the
products
described
herein
meet
applicable ANSI,
IEEE
and
NEMA
standards;
but
no
such
assurance
is
given,
with
respect
to
local
codes
and
ordinances
because
they
vary
greatly.
3

GEK-34053
APPLICATION
The
inverse
time—current
characteristics
make
the
IAC51
and
IACS2
relays
well
suited
for
multi—phase
and
phase—to—ground
fault
protection
of
commercial,
industrial,
and
utility
distribution
systems,
and
frequently
for
overload
back-up
protection.
They
are
particularly
well
suited
for
application
in
locations
where
the
fault—current
magnitude
is
dependent
mainly
upon
the
location
of
the
fault relative
to the
relay
and
only
slightly
upon
the
system
generating
setup
at
the
time
of
the
fault.
The
general
practice
is
to
use
a
set
of
three
relays
for
interphase
faults
and
a
separate
relay,
residually
connected,
for
single—phase—to—ground
faults.
Use
of
a
separate
ground
relay
is
advantageous
because
it
can
be
adjusted
to
provide
more—sensitive
protection
on
ground
faults.
Typical
connections
for
such
an
application
are
shown
in
Figure
14.
A
typical
application
and
external
connections
of
the
IAC52A,
which
has
two
closing
contacts, is
shown
in
Figure
15.
Care
should
be taken
in
applying
this
relay,
since
simultaneous
closing
of
both
contacts
may
not
occur.
In
the
application
of
IAC51
and
52
relays
with
automatic
reclosing
devices,
the
reset
time
should
be
considered.
The
reset
time
of
all
relays
covered
by
these
instructions
is
approximately
seven
seconds
(7 secs),
from
the
fully—closed
to
the
fully—open
position,
when
set
at
number
10
on
the time
dial.
When
setting
these
relays
to coordinate
with
downstreamu
relays,
a
coordination
time
of
from
0.25
to
0.40
second
is
generally
allowed.
These
coordination
times
include,
in
addition
to breaker—clearing
time,
0.10
second
for
relay
overtravel
and
0.17
second
for
safety
factor.
For
example,
if
the breaker—clearing
time
is
0.13 second
(8
cycles),
the
coordination
time
would
be
0.40
second.
If
the
relay
operating
time
is set
by test
at
the
current
level
in
question,
the
safety factor
may
be
reduced
from
0.17
to
0.07 second
with
relay
overtravel
of .10
second.
Then
if the
“downstream”
breaker
time
is
5
cycles
(0.08
sec)
a
minimum
of
0.25
second
could
be
allowed
for
coordination.
CONSTRUCTION
The
induction
unit
is
the
basic
unit
in
all
Type—IAC
relays.
Figures
2
and
3 show
the
induction
unit
mounted
in
the
cradle.
These
units
are
of
the
induction—disk
construction
type.
The
disk
is
actuated
by a
current—operating
coil
on
a laminated
U—magnet.
The
disk
shaft
carries
the
moving
contact,
which
completes
the
alarm
or
trip
circuit
when
it
touches
the
stationary
contact
or
contacts.
The
disk
shaft
is
restrained
by
a
spiral
spring
to
give
the
proper
contact—closing
current,
and
its
motion
is
retarded
by a
permanent
magnet
acting
on
the
disk
to give the
correct
time
delay.
There
is
a
target
and
seal—in
unit
mounted
on
the
front,
to
the
left
of
the
shaft
of
the
time—overcurrent
unit.
The
seal—in
unit
has
its
coil
in
series
and
its
contacts
in
parallel
with
the
contacts
of
4

GEK-34053
the
time—overcurrent
unit,
such
that
when
the
induction—unit
contacts
close,
the
seal—in
unit
picks
up
and
seals
in.
When
the
seal—in
unit
picks
up,
it
raises
a
target
into
view,
which
latches
up
and
remains
exposed
until
released
by
pressing
a
button
beneath the
lower
left
corner
of
the
cover.
The
instantaneous
unit
is
a
small
hinge—type
unit,
which
is
mounted
on
the
front
of
the
B
models
to
the
right
of
the
shaft
of
the
time—overcurrent
unit.
Its
contacts
are
normally
connected
in
parallel
with
the
contacts
of
the
time—overcurrent
unit
and
its
coil
is
connected
in
series
with
the
time—overcurrent
unit.
When
the
instantaneous
unit
picks
up
it
raises
a
target,
which
latches
up
and
remains
exposed
until
it
is
released.
The
same
button
that
releases
the
target
of
the
seal—in
unit
also
releases
the
target
of
the
instantaneous
unit.
RATINGS
TIME-OVERCURRENT
UNIT
Ratings
for
the
time—overcurrent
unit
are
shown
in Table
I.
TABLE
I
PICKUP
RANGE,
AMPERES
RELAY
FREQUENCY
MAIN
(TIME)
INSTANTANEOUS
CYCLES
UNIT UNIT
IAC51A
and
50
0.5
-
4.0
IAC52A
60
2.0
-
16.0
IAC51B
and
50
0.5
-
4.0
0.5
—
4.0
IAC52B
60
2.0
—
16.0
2.0
-
16.0
10.0
-
80.0
20.0
-
160.0
Available
taps
of
the
time—overcurrent
unit
are
shown
on
Table
II.
TABLE
II
RANGE,
AMPERES
TAPS
AVAILABLE
(AMPERES)
0.5
-
4.0
0.5,
0.6. 0.7,
0.8
1.0,
1.2, 1.5,
2.0,
2.5, 3.0,
4.0
2.0
-
16
2.0, 2.5,
3.0,
4.0,
5.0,
6.0, 7.0,
8.0,
10.0,
12.0.
The
one—second
thermal
ratings
are
listed
in Table
III.
5

GE
K-34053
TABLE
III
TIME
OVERCURRENT
UNIT
ONE
SECOND
K
(AMPS) RATJNG(AMPS)
0.5
-
4.0
70.0
4,900.0
2.0
-
16.0
260.0
67,600.0
For
ratings
for
less
than
one
second,
the
rating
may
be
calculated
according
to
the
formula
K
T
where
T
is
the
time,
in
seconds,
that
the
current
flows.
The
continuous
ratings
of
the
time—overcurrent
units
are
shown
in
Tables
IV
and
V.
TABLE
IV
0.5
-
4.0
AMP RANGE
TAP
0.5 0.6
0.7
0.8
1.0
1.2
1.5
2.0
2.5 3.0
4.0
RATING
1.6
1.8
2.0
2.1
2.3 2.7
3.0
3.5
4.0 4.5
5.0
TABLE
V
2.0
-
16.0
AMP
RANGE
TAP
2.0
2.5
3.0
4.0
5.0
6.0 7.0
8.0
10.0
12.0
16
RATING
8.0
9.0
10.0
12.0
14.0 15.0 16.0 17.5
20.0
20.0
20.0
INSTANTANEOUS
UNIT
The
instantaneous
unit
has
a double—wound
coil
for
operation
on
either
one
of
two
ranges.
Any
setting
obtained
in
the
lower
range
(series
connected)
is
doubled,
within
±10%,
when
the
unit
is
connected
for
high—range
operation
(parallel
connected).
The
instantaneous
unit
has
a
continuous
rating
of
1.5 times
minimum
setting
or
25
amperes, whichever
is
smaller.
Example:
the
2.0—16.0
ampere
instantaneous
unit,
when
set
on
the
low
range
(2.0—
8.0
amperes) has
a
continuous
rating
of
3.0
amperes,
and
when
connected
for
high—range
operation
(4.0—16.0
amperes)
has
a
continuous
rating
of
6.0
amperes.
The
continuous
and
one—second
ratings
for
the
instantaneous
unit
are
shown
in
Table
VI.
6

GEK-34053
TABLE
VI
RANGE
CONNECTIONS
CONTINUOUS
I-
ONE
K
if
RATING
SECOND
0.5
-
4.00
0.5
-
2.00
S
0.75 25.0
625
1.0
-
4.00
P
1.5
50.0 2,500
2.0
-
16.0
2.0
-
8.00
S
3.0
130.0
16,900
4.0
-
16.00
P
6.0
260.0 67,600
10.0
-
80.0
10.0
-
40.0
S
15.0
400.0
160,000
20.0
-
80.0
P
25.0 600.0
360,000
20.0
-
160.0
20.0
-
80.0
S
25.0
600.0
360,000
40.0
-
160.0
P
25.0
600.0
360,000
I
Higher
currents
may
be
applied
for
shorter
lengths
of time
in
accordance
with
the
formula
K
1=!—
‘I,
where
T
is
the time,
in
seconds,
that
the
current
flows.
It
S
Series
connected,
P
=
Parallel
connected
TARGET
AND
SEAL-IN
UNIT
Ratings
for
the
target
and
seal—in
unit
are
shown
in
Table
VII
TABLE
VII
TAP
0.2
2.0
D.C.
Resistance
±10%
(ohms)
7
0.13
Mi
Operating
(amperes)
+0
-
25%
0.2
2.0
Carry
Continuously
(amperes)
0.3
3.0
Carry
30
Amps
for
(sec.)
0.03
4.0
Carry
10
Amps
for
(sec.)
0.25 30.0
60
Hz
Impedance
(ohms)
52.0
0.53
If
the
tripping
current
exceeds
30
amperes
an
auxiliary
relay
should
be
used,
the
connections
being
such
that
the
tripping
current
does
not
pass
through
the
contacts
of
the
target
and
seal—in
coils
of
the
protective
relay.
CONTACTS
The
current—closing
rating
of
the
contacts
is
30
amperes
for
voltages
not exceeding
250
volts.
The
current—carrying
rating
is
limited
by the
ratings
of
the
seal—in
unit.
7

GEK-34053
BURDENS
Burdens
for the
time—overcurrent
unit are
given in Table VIII.
TABLE
VIII
RANGE
HZ MIN.
BURDENS
AT MIN.
BURDENS IN
V.A. AT
5
AMPS
TAP PICKUP
MIN. TAP
OHMS (1)
CALCULATED
FROM
IMPEDANCE AT MIN.
PICKUP
(121)
R Z
3 10 20.0
TIMES
TIMES TIMES
PICK- PICK- PICK
UP
UP UP
0.5
- 0.4 60 0.5 5.60 21.0 22.0
10.80 5.00 3.66
550.0
2.0 - 15.0 60
2.0
0.37 1.44 1.45
0.65
0.32 0.24 36.3
NOTE: The impedance values
given are
those for
the minimum
tap
of
each relay. The impedance for other taps
at
pick
up
current (tap rating) varies
inversely (approximately) as
the
square of the
tap rating.
For
examp1e for
a
relay
with
0.5-4.0
amp range, the impedance
of the 0.5 amp tap
is given
as
22.0 ohms. The
impedance of the
2.0 amp
tap
at 2.0 amperes is
(.5/2)2
x 22
= 1.37
ohm.
The instantaneous
unit burdens are listed
in
Table
IX.
TABLE IX
BURDENS AT MIN. BURDENS IN
RANGE
tCON-
MIN.
PICKUP
MIN. TAP OHMS (1)
60
HZ
NEC- TAP
___________________ __________________
RELAYS TIONS AMPS R Z
3
10 20.0 V.A. AT
5AMPS
ONLY
OHMS OHMS OHMS TIMES TIMES TIMES CALCULATED
FROM
(AMPS) PICK PICK PICK
IMPEDANCE
AT MIN.
UP
UP UP PICKUP
(12Z)
O
5—4
0
LOW
0.5
12.7
11.5 17.1 9.6
8.7
8.2 427.5
HIGH
1.0 3.18 2.87
4.28 2.40 2.18 2.04 107.0
2 0-16 0
LOW 2.0 0.76 0.72 1.05 0.59 0.53
0.50
26.25
HIGH
4.0 0.189
0.180 0.261 0.147 0.133 0.125
6.63
10
0-80 0
LOW
10.0
0.042 0.029 0.051
0.029 0.026 0.024 1.28
HIGH 20.0
0.010 0.007 0.013 0.007
0.007
0.006 0.33
20.0-160.0
LOW 20.0
0.015 0.008
0.017
0.010
0.009
0.008
0.43
HIGH
40.0
0.004
0.002
0.004
0.002 0.002
0.002
0.10
j-
Low means two
windings
connected
in
series.
High means two
windings
connected
in parallel.
See
Internal-Connections
diagram
for
additional
information.
8

GEK-34053
CHARACTERI
STICS
Pickup
of
these
relays
is
defined
as
the
current
required
to
close
the
contacts
from
the
0.5
time—dial
position.
The
pickup
value
of
the
IAC51
relays is
within
3%
of
tap
value.
The
setting
of the
time
dial
determines
the
length
of
time
the
unit requires
to
close
its
contacts
when
the
current
reaches
the
predetermined
value.
The
contacts
are
just
closed
when
the
dial
is
set
at
zero.
When
the
dial
is
set
at 10,
the
disk
must
travel
the
maximum
distance
to
close
the
contacts;
this
gives
the
maximum
time
setting.
The
unit
resets
at
90%
of
the
minimum
closing
value
of
current.
The
time
to
reset
to the
No.
10
time—dial
position
when
the
current
is
reduced
to zero
is
approximately
7
seconds.
Figure
9 shows
the
50
Hz
and
Figure
10
shows
the
60
Hz
time/current
characteristics
for
relay
types
IAC51
and
1AC52.
The
time/current
curve
for
the
instantaneous
unit
is
shown on
Figure
8.
RECEIVING,
HANDLING,
AND
STORAGE
These
relays,
when
not
included
as
a
part
of
a control
panel,
will
be
shipped
in
cartons
designed
to
protect
them
against
damage.
Immediately
upon
receipt
of
a relay,
examine
it
for
any
damage
sustained
in
transit.
If
injury
or
damage
resulting
from
rough
handling
is
evident,
file
a
damage
claim
at
once
with
the
transportation
company
and
promptly
notify
the
nearest
General
Electric
Sales
Office.
Reasonable
care
should
be
exercised
in
unpacking
the
relay
in
order
that
none
of
the
parts
are
injured
nor
the
adjustments
disturbed.
If the
relays
are
not
to be
installed
immediately,
they
should
be
stored
in
their
original
cartons
in
a place
that
is
free
from
moisture,
dust,
and
metallic
chips.
Foreign
matter
collected
on
the
outside
of
the
case
may
find
its
way
inside
when
the
cover
is removed
and
cause
trouble
in
the
operation
of
the
relay.
ACCEPTANCE
TESTS
Immediately
upon
receipt
of
the
relay
an
INSPECTION
AND
ACCEPTANCE
TEST
should
be made
to
make
sure
that
no
damage
has
been
sustained
in
shipment
and
that
the
relay
calibrations
have
not
been
disturbed.
If
the examination
or
test
indicates
that
readjustment
is
necessary,
refer
to the
section
on
SERVICING.
These
tests
may
be
performed as
part
of
the
installation
or
as
acceptance
tests,
at the
discretion
of
the
user.
Since
most
operating
companies
use
different
procedures
for
acceptance
and
for
installation
tests,
the
following
section
includes
all
applicable
tests
that
may
be
performed
on
these
relays.
9

GEK-34053
VISUAL
INSPECTION
Check
the
nameplate
stamping
to
make
sure
that
the
model
number
and
rating
of
the
relay
agree
with
the
requisition.
Remove
the
relay
from
its
case
and
check
that
there
are
no
broken
or
cracked
molded
parts
or
other
signs
of
physical
damage,
and
that
all
screws
are
tight.
MECHANICAL
INSPECTION
1.
There
should
be
no
noticeable
friction
when
the
disk
is
rotated
slowly
clockwise.
The
disk
should
return
by
itself
to
its
rest
position.
2.
Make
sure
the
control
spring
is
not
deformed,
nor
its
convolutions
tangled
or
touching.
3.
The
armature
and
contacts
of
the
seal—in
unit,
as
well
as
the
armature
and
contacts
of
the
instantaneous
unit,
should
move
freely
when
operated
by
hand;
there
should
be
at
least
1/32”
wipe
on
the
seal—in
contacts.
4.
The
targets
in
the
seal—in
unit
and
in
the
instantaneous
unit
must
come
into
view
and
latch
when
the
armatures
are
operated
by
hand,
and
should
unlatch
when
the
target
release
lever
is
operated.
5.
Make
sure
that
the
fingers
and
shorting
bars
agree
with
the
internal—connections
diagram.
CAUTION
Every
circuit
in
the
drawout
case
has
an
auxiliary
brush.
It
is
especially
important
on
current
circuits
and
other
circuits
with
shorting
bars
that
the
auxiliary
brush
be
bent
high
enough
to
engage
the
connecting
plug
or
test
plug
before
the
main
brushes
do.
This
will
prevent
Current
Transformer
(CT)
secondary
circuits
from
being
opened.
See
Figure
1.
ELECTRICAL
TESTS
DRAWOUT
RELAYS,
GENERAL
Since
all
drawout
relays
in
service
operate
in
their
cases,
it
is
recommended
that
they
be
tested
in
their
cases
or
an
equivalent
steel
case.
In
this
way,
any
magnetic
effects
of
the
enclosure
will
be
accurately
duplicated
during
testing.
A
relay
may
be
tested
without
removing
it
from
the
panel
by
using
a
12XLA13A
test
plug.
This
plug
makes
connections
only with
the
relay
and
does
not
disturb
any
shoring bars
in
the
case.
The
12XLA12A
test
plug
may
also
be
used.
Although
this
test
plug
allows
greater
testing
flexibility,
it
requires
C.T.
shorting
jumpers
and
the
exercise
of
greater
care,
since
connections
are
made
to
both
the
relay
and
the
external
circuitry.
10

GEK-34053
POWER
REQUIREMENTS,
GENERAL
All
devices
operating
on
alternating
current
(AC)
are
affected
by
frequency.
Since
non—sinusoidal
waveforms
can
be
analyzed
as
a
fundamental
frequency
plus
harmonics
of
that
fundamental
frequency,
it
follows
that
alternating—current
devices
(relays)
will
be
affected
by
applied
waveforms.
AC
relays
(and
AC
devices
in
general)
are
significantly
affected
by
the
application
of
non—sinusoidal
waveforms.
Therefore,
in
order
to
test
AC
relays
properly
it
is
essential
to
use
a
test
voltage
and/or
current
waveform
that
is
sinusoidal.
The
purity
of
the
sine
wave
(i.e.,
its
freedom
from
harmonics)
cannot
be
expressed
as
a
finite
number
for
any
particular
relay;
however,
any
relay
using
tuned
circuits,
RL
or
RC
networks,
or
saturating
electromagnets
(such
as
time—overcurrent
relays)
would
be
especially
affected
by
non-sinusoidal
wave
forms.
TIME-OVERCURRENT
UNIT
Rotate
the
time
dial
slowly
and
check,
by
means
of
a
lamp
in
the
circuit,
that
the
contacts
just
close
at
the zero
(0)
time—dial
setting.
The
point
at
which
the
contacts
just
close
can
be
adjusted
by
running
the
stationary
contact
brush
in
or
out
by
means
of
its
adjusting
screw.
This
screw
should
be
held
securely
in
its
support.
With
the
contacts
just
closing
at
No.
0
time—dial
setting,
there
should
be
sufficient
gap
between
the
stationary
contact
brush
and
its
metal
backing
strip
to
ensure
approximately
1/32”
wipe.
The minimum
current
at
which
the
contacts
will
just
close
is
determined
by
the
position
of
the
tap
screw
in
the
tap
block
at
the
top
of
the
relay.
When
changing
the
current
setting
with
the
relay
in
its
case,
remove
the
connection
plug,
to
short
the
current—transformer
secondary
circuit.
Next,
screw
the
tap
screws
into
the tap
marked
for
the
desired
current,
and
then
replace
the
connection
plug.
The
pickup
of
the
unit
for
any
current
tap
is
adjusted
by
means
of
a
spring—adjusting
ring.
See
Figure
2.
The
ring
may
be
turned
by
inserting
a
screw
driver
in
the notches
around
the
edge.
By
turning
the
ring,
the
operating
current
of
the
unit
may
be
brought
into
agreement with
the tap
setting
employed
if,
for
some
reason,
this
adjustment
has
been
disturbed.
This
adjustment
also
permits
any
desired
setting
intermediate
between
the
various
tap
settings
to
be
obtained.
The
unit
is
adjusted
at
the
factory
to
close
its
contacts
from
any
time—dial
position
at
a
minimum
current
within
five
percent
(5%)of
the
tap
plug
setting.
The
unit
resets
at
90%
of
the
minimum
closing
value.
Time
Setting
The
setting
of
the
time
dial
determines
the
length
of
time
the
unit
requires
to
close
its
contacts
when
the
current
reaches
a
11

GEK-34053
predetermined
value.
The
contacts
are
just
closed
when
the
dial is
set
on
0.
When
the
dial
is
set
on
10,
the
disk
must
travel
the
maximum
amount
to
close
the
contacts;
therefore
this
setting
gives
the
maximum
time
setting.
The
primary
adjustment
for
the
time
of
operation
of
the
unit
is
made
by
means
of
the
time
dial.
However,
further
adjustment
is
obtained
by
moving
the
permanent
magnet
along
its
supporting
shelf;
moving
the
magnet
toward
the
disk
shaft
decreases
the
time,
while
moving
it
away
increases
the time.
Pickup
Test
Use
rated
frequency
for
both the
pickup
and
time
tests.
Set
the
relay
at
the
0.5
time-dial
position
and
2.0
ampere
tap.
Using
the
test
connections
in
Figure
13,
the
main
unit
should
close
its
contacts
within
±2.0%
of
tap
value
current
(1.96—2.04
amp).
All
other tap
positions
should
pick
up
at
tap
value
±5%
of
tap
value.
Time
Test
Set
the
relay
at
No.
5
time—dial
setting
and
2.0
amp
tap.
Using
the
test
connection
in Figure
13,
apply
five
times
tap
current
(10.0
amp)
to
the
relay.
The
relay
should
operate
in
1.78 seconds
±0.09
second.
At
2
times
tap
current
and
10
times
tap
current,
the
operating
time
should
agree
with
the
time—curve
value
±7%.
INSTANTANEOUS
UNIT
Make
sure
that
the
instantaneous
unit
is
wired
for
the
range
in
which
it
is
to
operate
(see
Internal—Connections
Diagram
Figure
5
or
Figure
7)
and
connected
as
indicated
in
test
circuit
Figure
13.
Whenever
possible,
use
the
higher
range,
since
the higher
range
has
a
higher continuous
rating.
Setting
the
Instantaneous
Unit
Loosen
the
locknut
and
turn
the
pole
piece
toward
the
desired
setting.
See
Figure
2.
Turning
the
pole
piece
up
increases
the
pickup;
turning
the
pole
piece
down
decreases
the pickup.
Bring
up
the
current
slowly
until
the
unit
picks
up.
It
may
be
necessary
to
repeat
this
operation
until
the
desired
pickup
value
is
obtained.
Once
the
desired
pickup
value
is
reached,
tighten
the
locknut.
CAUTION
The
instantaneous
unit
is
rated
1.5
times
minimum
pick
up.
Do
not
leave
the
test
current
on
too
long as
it
may
damage
the
unit.
12

GEK-34053
Pickup
Test
With
the
unit
connected
for
high—range
operation
(parallel
connections)
and
the target
in
the
uDownu
position,
check
the pickup
at
the maximum
calibration
mark;
the
pickup
should
be
within
the
limits
in
Table
X.
TABLE
X
UNIT
RANGE
MINIMUM
CALIBRATION
MAXIMUM
AMPERES AMPERES AMPERES
AMPERES
0.5
-
4.0
3.6
4.0
4.5
2.0
—
16.0 14.4
16.0 17.7
10.0
-
80.0
72.0
80.0 89.0
20.0
-
160.0 144.0 160.0
177.0
TARGET
AND
SEAL-IN
UNIT
The
target
and seal—in
unit
has
an
operating
coil
tapped
at
0.2
and
2.0
amperes.
The
relay
is
shipped
from
the
factory
with
the tap
screw
in
the
lower—ampere
position.
The
tap
screw
is
the
screw
holding
the
right—hand
stationery
contact.
To
change
the tap
setting,
first
remove
one
screw
from
the
left—hand
stationary
contact
and
place
it
in
the
desired
tap.
Next,
remove
the
screw
from
the
first,
undesired,
tap
and
place
it
on
the
left
hand
stationary
contact
where
the
first
screw
was
removed.
See
Figure
2.
This
procedure
is
necessary
to
prevent
the
right—hand
stationary
contact
from
getting
out
of
adjustment.
Screws
should
never
be
left
in
both
taps
at
the
same
time.
Pickup
and
Dropout
Test
1.
Connect
relay
studs
1
and
2
(See
Internal—Connections
Diagram)
to
a
DC
source,
ammeter and
load
box
so
that
the
current
can
be
controlled
over
a
range
of
0.1 to
2.0
amperes.
2.
Turn
the
time
dial
to
the
ZERO (0)
TIME
DIAL position.
3.
Increase
the
current
slowly
until
the seal—in
unit
picks
up.
See
Table
XI.
4.
Move
the
time
dial
away
from
the
ZERO
TIME—DIAL
position;
the
seal—in
unit
should
remain
in
the
picked—up
position.
5.
Decrease
the
current
slowly
until
the
seal—in
unit
drops
out.
See
Table
XI.
13

GEK-34053
TABLE
XI
TAP
PICK-UP
DROPOUT
CURRENT
CURRENT
0.2
0.14
-
0.195
.050
OR MORE
2.0
1.40
-
1.95 .50
OR
MORE
INSTALLATION
The
following
tests
are
to
be
performed
at
the
time
of
installation.
TIME-OVERCURRENT
UNIT
1.
Set
the
tap
screw
in
the
desired
tap.
Using
the
test
circuit
in
Figure
13,
apply
approximately
twice
tap
value
until
contacts
just
close.
Reduce
the
current
until
the
light
in
series
with
the
contacts
begins
to
flicker.
This
value
of
current
is
defined
as
pickup,
and
should
be
within
5%
of
tap
value.
2.
Check
the
operating
time
at
TD
=
5,
tap
=
2
or
minimum
value,
and
I
=
5
times
tap
current.
The
operating
time
should
be
the
time
shown
on
the
time—current
curve
±7%.
TARGET
AND
SEAL-IN
UNIT
1.
Make
sure
that
the
tap
screw
is
in
the
desired
tap.
2.
Perform
pickup
and
dropout
tests,
as
outlined
in
the
ACCEPTANCE
TESTS
section.
INSTANTANEOUS
UNIT
1.
Select
the
desired
range
by
making
the proper
connections
at
the
rear
of
the
relay
(See
Internal—Connections
Diagram).
Whenever
possible,
be
sure
to
select
the
higher
range
since
it
has
a
higher continuous
rating.
2.
Set
the
instantaneous
unit
to
pick
up
at
the
desired
current
level.
See
SETTING
THE
INSTANTANEOUS
UNIT
in
the
ACCEPTANCE
TESTS
section.
All
the
tests
described
above
under
Installation
Tests
must
be
performed
at
the
time
of
installation.
In
addition,
If
those
tests
described
under
the
ACCEPTANCE
TESTS
section
were
not performed
prior
to
installation,
it
is
recommended
they
be
performed
at
this
time.
14

(5EK-34053
PERIODIC
CHECKS
AND
ROUTINE
MAINTENANCE
In
view
of the
vital
role
of
protective
relays
in
the
operation
of
a
power
system,
it
is
important
that a
periodic
test
program
be
followed.
It
is
recognized
that
the
interval
between
periodic
checks
will
vary
depending
upon
environment,
type
of
relay
and
the
user’s
experience
with periodic
testing.
Until
the
user
has accumulated
enough
experience
to
select
the
test
interval
best
suited
to
his
individual
requirements,
it
is
suggested
that the
points
listed
below
be
checked
at
an
interval
of
from one
to
two
years.
These tests
are
intended
to
make sure
that
the
relays
have
not
deviated
from their
original
setting.
[f
deviations
are
encountered,
the
relay
must
be
retested
and
serviced
as
described
in
this
manual.
TIME-OVERCURRENT
UNIT
1.
Perform
Pickup
Test as
described
in
the
ACCEPTANCE
TESTS
section
for
the
tap
in
service.
2.
Perform
the
Time
Test
as
described
in
the
ACCEPTANCE
TESTS
section.
INSTANTANEOUS
UNIT
1.
Check
that
the
instantaneous
unit
picks
up
at
the
desired
current
level,
as
outlined
in
the
ACCEPTANCE
TESTS
section.
TARGET
AND
SEAL-IN
UNIT
1.
Check
that
the
unit
picks
up
at
the
values
shown
in
table
XI.
2.
Check
that
the
unit
drops
out
at
30%
or
more
of
tap
value.
CONTACT
CLEANING
For
cleaning
relay
contacts,
a
flexible
burnishing
tool
should
be
used.
This
consists
of
a
flexible
strip
of
metal with
an
etch—
roughened
surface,
resembling in
effect
a
superfine
file.
The
polishing
action
is
so
delicate
that no
scratches
are left,
yet
it
will
clean
off
any
corrosion
thoroughly
and
rapidly.
Its
flexibility
ensures
the
cleaning
of
the
actual
points
of
contact.
Do
not
use
knives,
files,
abrasive
paper
or
cloth
of
any
kind
to
clean
relay
contacts.
SYSTEM
TEST
Although
this
Instruction
Book
is
primarily
written
to
check
and
set
the
IAC
relay,
overall
functional
tests
to
check
the system
operation
are
recommended
at
intervals
based
on
the
customer’s
experience.
15

GE
K-34053
SERVICING
TIME-OVERCURRENT
UNIT
If
it
is
found
during
installation
or
periodic
testing
that
the
time—overcurrent
unit
is
out
of
limits,
the
unit
may
be
recalibrated
as
follows:
Pickup
Tests:
The
pickup
of
the
unit
for
any
current
tap
is
adjusted
by
means
of
a
spring—adjusting
ring.
The
ring
may
be
turned
by
inserting
a
screw
driver
in
the notches
around
the
edge.
By
turning
the
ring,
the
operating current
of
the
unit
may
be
brought
into
agreement
with
the
tap
setting
employed
if,
for
some
reason,
this
adjustment
has
been
disturbed.
This
adjustment
also
permits
any
desired
setting
intermediate
between
the
various
tap
settings
to
be
obtained.
The
unit
is
adjusted
at
the
factory
to
close
its
contacts
from
any
time—
dial
position
at
a
minimum
current
within
five
percent
(5%)
of
the
tap
plug
setting.
The
unit
resets
at
90%
of
the
minimum
closing
value.
Rotate
the
time
dial
to
the
No.
0
time—dial
setting
and
check,
by
means
of
a
lamp
in
the
circuit,
that
the
contacts
just
close.
The
point
at
which
the
contacts
just
close
can
be
adjusted
by
running
the
stationary
contact
brush
in
or
out
by
means
of
its
adjusting
screw.
This
screw
should
be
held
securely
in
its
support.
With
the
contacts
just
closing
at
No.
0
time—dial
setting,
there
should
be
sufficient
gap
between
the
stationary
contact
brush
and
its
metal
backing
strip
to
ensure
approximately
1/32”
wipe.
Connect
the
operating-coil
terminals
to
a
source
of
the
proper
frequency
and
good
wave
form,
having
a
voltage
of
120
or
more,
with
pure
resistance
load
boxes
for
setting
the
current.
See
Test—Circuit
Figure
13.
With
the
tap
plug
in
the
2
amp
tap
and
the
time
dial
set
where
contacts
are
just
open,
adjust
the
control
spring
to
just
close
the
contacts
within
the
limits
given
below,
which
are
plus
and
minus
2
percent
(±2%)
of
tap
amps.
See
Table
XII.
TABLE
XII
TAP
RANGE
TAP
MINIMUM
AMPS
MAXIMUM
AMPS
0.5
-
4.0
2
AMP
1.96
2.04
2.0
-
16.0
2
AMP
1.96
2.04
It
should
never
be
necessary to
wind
up
the
control—spring
adjuster
more
than
30°
(one
notch)
or
unwind
it
more
than
90°
(three
notches)
from
the
factory
setting
to
obtain
the
above
pick
up
setting.
16

GEK-34053
With
the
tap
plug
in the
2
amp
tap
and
the
time dial
at
No.
10
time
setting,
check
the
current
required
to
just
move
the
disk
away
from
the
stop
arm.
This
current
should
be
within
the
limits
shown
in
Table
XIII,
which
are
±6% of
tap
amperes.
If
the
disk
moves
at
the
lower
limit,
check
that
the
movement
is
not over
one—half
inch
(1/2”)
measured
along
the
periphery
of
the
disk.
TABLE
XIII
TAP
RANGE
TAP
MINIMUM
AMPS
MAXIMUM
AMPS
0.5
-
4.0
2
AMP
1.88
2.12
2.0
- 16.0
2
AMP
1.88
2.12
Time
Tests
With
the tap
plug
in
the
2
amp
tap
and
the
time
dial
at
No.
5
time
setting,
apply
five
times
(5x)
tap current
to
the
relay.
*
Adjust
the
drag
magnet
to obtain
a
closing
time
as
near
as
possible
to
1.78
seconds,
but
at
least
between
1.69 and
1.87 seconds.
The
magnet
should
be
approximately
in the
middle
of
its
travel.
The
magnet
is
adjusted
by
loosening
the
nut
under
the
magnet
shelf.
Moving
the
magnet
in
decreases
the time.
Moving
the
magnet
out
increases
the
time.
When
adjusting
the
drag
magnet,
be
sure
the
outer
edge
of
the
magnet
never
extends
out
beyond
the
cutout
in
the
disk.
Be
sure
the
screw clamping
the
drag
magnet
to its
supporting
shelf
is
tight
before
proceeding
with
other
time checks.
Make
sure
the
drag
magnet
does
not
hit
the
counterweight
at
any
position
of
the
disk.
With
the
tap
plug
in
the
2
amp
tap
and
the
time
dial
at
the
No.5
time
setting,
check
the
contact
closings
at
2
and
10
times
tap
value.
These
closing
times
must
be
within
the
limits
shown
on
Table
XIV.
TABLE
XIV
60HZ 50HZ
MAX
SEC.
2.0
4.0
3.5.
4.07
3.52
4.06
2.0
20.0
1.19
1.37
1.13 1.31
INSTANTANEOUS
UNIT
1.
Both
contacts
should
close
at
the
same
time.
2.
The
backing
strip
should
be
so
formed
that
the
forked
end
(front)
bears
against
the
molded
strip
under
the
armature.
*Revised
since
last
issue
17
TAP
AMPS
MIN
SEC.
MAX
SEC.
MIN.
SEC.

GEK-34053
3.
With
the
armature
against
the
pole
piece,
the
cross
member
of the
“T”
spring
should
be
in
a horizontal
plane
and
there
should
be
at
least
1/32
inch
wipe
on
the
contacts.
Check
this
by
inserting
a
0.012
inch
feeler
gage
between
the
front
half
of the
shaded
pole
and
the
armature,
with
the
armature
held
closed.
The
contacts
should
close
with
the feeler
gage
in
place.
TARGET
AND SEAL-IN
UNIT
Check
steps
1 and
2
as
described
under
INSTANTANEOUS
UNIT
above.
To
check
the
wipe
of
the
seal—in
unit,
insert
a
0.012
inch
feeler
gage
between
the
plastic
residual
of
the
armature
and
the
pole
piece,
with
the armature held
closed.
The
contacts
should
close
with
the
feeler
gage
in
place.
RENEWAL
PARTS
It
is
recommended
that
sufficient
quantities
of renewal
parts
be
carried
in
stock
to
enable
the
prompt
replacement
of
any
that
are
worn,
broken,
or
damaged.
When
ordering
renewal
parts,
address
the
nearest
Sales Office of
the
General
Electric
Company,
specify
the
quantity
required
and the
name
of
the part
wanted,
and
the
complete
model
number
of
the
relay
for
which
the
part
is
required.
Since
the
last
edition,
changes
have
been
made
in
ELECTRICAL
TESTS/TIFIE-OVERCURRENT
UNIT/Time
Test,
and
INSTALLATION/TIME
OVERCURRENT
UNIT,
step
2.
18

GEK-34053
LIST
OF
FIGURES
FIGURE
PAGE
1
Cutaway
of
Drawout
Case
Showing
Position
of
Auxiliary
Brush
and
Shorting
Bar
20
2
Type
IAC51
800
Series
Relay
Removed
from Case
(Front
View)
21
3
Type
IAC51
800
Series
Relay
Removed
from
Case
(Rear
View)
22
4
Type
IAC51A
800
Series
Relay
Internal
Connections
(Front
View)
23
5
Type
IAC51B
800
Series
Relay
Internal
Connections
(Front
View)
24
6
Type
IAC52A
800
Series
Relay
Internal
Connections
(Front
View)
25
7
Type
IAC52B
800
Series
Relay
Internal
Connections
(Front
View)
25
a
Time/Current
Characteristics
of
the
Instantaneous
Unit
26
9
Time/Current
Characteristics
of
50Hz
Types
IAC51
and
1AC52
800
Series
Relays
27
10
Time/Current
Characteristics
of 60Hz
Types
IAC51
and
1AC52
800
Series
Relay
28
11
Saturation
Curves
of
Lowest
Taps
of
the
Induction
Unit
of
Type—TAC
Relays
with
Inverse-Time
Characteristics
.
. 29
12
Outline
and
Panel
Drilling
for
Types
IAC51A,
IAC51B,
IAC52A,
and
IAC52B
800
Series
Relays
30
13
Test
Connections
for
Testing
Pickup
and
Time
Curves
of
IAC
Relays
31
14
External
Connections
of
Four
IAC51A
Relays
Used
for
Multi-Phase
and
Phase—to—Ground
Fault
Protection
of
a
3—Phase
Circuit
32
15
External
Connections
of
Four
IAC52A
Relays
Protecting
a
3—Phase
Circuit
Against Multi-Phase
and
Phase—to—Ground
Faults
33
19

GEK-34053
CONNECTING
PLUG
MAIN
BRUSH
NOTE:AFTER
ENGAGING
AUXILIARY
BRUSH,
CONNECTING
PLUG
TRAVELS
1/4
INCH
BEFORE
ENGAGING
THE
MAiN
BRUSH
ON
THE
TERMINAL
BLOCK
Figure
1
(8025039)
Cutaway
of
Drawout
Case
Showing
Position
of
Auxiliary
Brush
and
Shorting
Bar
CONNECTING
BLOCK
AUXILIARY
BRUSH
TERMINAL
BLOCK\
SHORTING
BAR
20