GE IAC60T User manual

IN
ST RU
CT
ION S
GEK-65573
TIME
OVERCURRENT
RELAYS
IAC6OT,
IAC8OT,
IAC9OT
GENERAL
ELECTRIC

GEK-65573
CONTENTS
PAGE
DESCRIPTION
3
APPLICATION
3
CONSTRUCTION
4
RATINGS
5
TIME
OVERCURRENT
UNIT
5
INSTANTANEOUS
OVERCURRENT
UNIT
7
AUXILIARY
UNIT
8
CONTACTS
P
BURDENS
8
TIME
OVERCURRENT
UNIT
8
INSTANTANEOUS
OVERCURRENT
UNIT
9
AUXILIARY
UNIT
9
CHARACTERISTICS
10
TIME OVERCURRENT
UNIT
10
INSTANTANEOUS
OVERCURRENT
UNIT
10
RECEIVING, HANDLING
AND
STORAGE
10
ACCEPTANCE
TESTS
11
VISUAL INSPECTION
11
MECHANICAL INSPECTION
11
TIME
OVERCURRENT
UNIT
11
INSTANTANEOUS
OVERCURRENT
UNIT
11
CAUTION
11
DRAWOUT
RELAY
TESTING
11
POWER
REQUIREMENTS
GENERAL
12
TIME
OVERCURRENT
UNIT
12
TIME
SETTING
12
PICKUP
TEST
13
TIME
TEST 13
INSTANTANEOUS
UNiT
13
PICKUP
AND
RESET
13
AUXILIARY
UNIT
13
INSTALLATION
14
INSTALLATION
TESTS
14
TIME
OVERCURRENT UNIT
14
INSTANTANEOUS
UNIT
14
AUXILIARY
UNIT 14
PERIODIC
CHECKS
AND
ROUTINE MAINTENANCE
15
TIME OVERCURRENT
UNIT
15
INSTANTANEOUS
UNIT
15
AUXILIARY UNIT
15
CONTACT CLEANING
15
SYSTEM TEST
15
SERVICING
16
MECHANICAL
ADJUSTMENTS 16
TIME
OVERCURRENT
UNIT
16
INSTANTANEOUS
UNIT
16
ELECTRICAL
ADJUSTMENTS
17
TIME OVERCURRENT
UNIT
17
INSTANTANEOUS
UNIT
17
RENEWAL
PARTS
18
LIST
OF FIGURES
19
2

GEK—65573
TIME
OVERCLJRRENT
RELAYS
IAC6OT, IAC8OT,
IAC9OT
DESCR
IPTION
The
IAC0T,
IAC8OT
and
IAC9OT
relays
consist
of
two
induction
disk
timer
overcurrent
units
with
wound
shading
coils
for
torque
control,
two
plunger-type
instantaneous
overcurrent
units
and one
dc
auxiliary
unit,
all
mounted in
the
L2
size
drawout
case.
The
three
models
differ
only
in
the
characteristic
of
the
time
overcurrent
unit,
which
is
inverse
in
the
IAC6OT,
very
inverse
in
the
IAC8OT
and
extremely
inverse
in
the
IAC9OT.
The
relays
do not
include
a
tarciet
seal-in
unit
since
this
feature
is provided
by the
associated
distance
relays.
The
time
overcurrent
units
are
adjustable
over
a
range
of
8
to
1;
the
instantaneous
units
have
an
adjustment
range
of
25
to
1.
The
available
ranges
in
amperes
of
both
the
time
and
instantaneous
units,
as well
as information
on
their
continuous
and
short
time
ratings,
are
provided
in
the
section
on RATINGS.
The
outline
and
mounting
dimensions
of
the
L2
size
drawout
case
are
shown
in
Fig.
15.
APPI
ICAT
ION
The
IAC6OT,
I1C80T
and
IAC9OT
relays
are
specifically
designed
for
use in
conjunction
with
two
zones
of
step—distance
relays.
In this
application
the
contacts
of
the
instantaneous
overcurrent
units
are
connected
to
supervise
the
first
zone
distance
relay
trip
circuit
to
prevent
incorrect
tripping
on
loss
of
the
ac
potential
supply.
The
time
overcurrent
units
are
torque
controlled
by means
of
wound
shading
coils
and
contacts
of
the
dc
auxiliary
unit.
The
second
zone
distance
relays
operate
the
auxiliary unit,
which
in
turn
completes
the
wound
shading
coil
circuit.
Subsequent
operation
of
the
time
overcurrent
units
provides
the
second
zone
time-delay
tripping.
This
arrangement
provides
the
means
for
obtaining
close
coordination
between
second
zone tripping
and
overcurrent
relays
or
fuses
installed
at tapped loads
on
the
line.
At
the
same
time
the
scheme
provides
a
definite
second
zone
reach
for
the
overall
line
protection
and
backup.
The
elementary
diagram
in
Fig.
10 illustrates
how
any one
of
the
three
IAC
relays
covered
by
this
instruction
book
may
be
used
in
conjunction
with
the
CEV51A
and
CEY52A
mho-type
distance
relays
to
provide
two—zone
protection
against
multi—phase
faults.
The
CEY51A
is
a
first-zone
directional
mho
relay
that
trips
without
time
delay
through
contacts
of
the
instantaneous
units
of
the
IAC
relay.
The
CEY52A
is
the
second
zone
directional
mho
relay
that
operates
the
dc
auxiliary
unit
in
the
JAC
relay
to
torque
control
the
time
overcurrent
unit.
The
time
overcurrent
unit
trips
the breaker via
the
CEY52A
contacts.
These
ntructiuns
do
not
purport
to
cover
all
details
or
variations
in
equipment
nor
to
provide
for
cvii-y
pcesibZ
contingency
to
be
met
n
cnneetion
with
installation,
operation
or
,rintenance.
Should
turthe
information
b
desi red or
houid
partJ
cular
problerro
arise
which
arm
not
covered
sufficiently
for
the
our
chaser’s
purposos, the
mat
ter ullauirt
be
referred
to
the
General
Tiectric
Company.
•
T
the
xtcnt
required
the urnjucts
descrl,ed
herein
r,ieet
applicable
aSsr.
1555
and
NEM4
standards;
hat
no
such
rssuranee
is
g;
yen
C;
th
respet
to
lonol
codes
and
ordinances
because they
vary
greatly.
3

GEK-65573
It
is
important to
note
that
the
instantaneous
overcurrent
units
in
the
IAC
relays
are
not
designed for
continuous operation
in the picked-up
position. For
this
reason
these
units
must
he
set
above
the
maximum
expected
full
load
current.
However, if
the
contacts
of
these
units
are
to
he
connected to supervise the
first
zone
CEY51A
contacts,
it
is obvious
that
they
must
operate
reliably
on
the
minimum
internal
line
fault
current.
The
range
and
characteristics
of
the
time
overcurrent
units
must
he selected
to
accomodate
the
desired
pickup
setting
and
at
the
same
time
permit
time
coordination
with
fuses
and
relays
at
other
points
on
the
system.
The
scheme
shown
in
Fig.
10 provides
protection against
multi—phase
faults.
Separate
ground
relays
must
be
used
for
protection against
single-phase-to—ground
faults.
CONSTRUCTION
The
inverse and
very
inverse
time
overcurrent units
consist
of a
tapped
current
operating coil
wound
on
a U—magnet
iron
structure. The
several
taps
on
the
operating
coil
are
connected
to
tap
points
on
a tap
block
to provide a ready
means
of selecting
the
pickup
point. The
U-magnet
includes
wound
shadinci
coils
which
are
connected
to
a
contact
of
the
auxiliary
unit
“A.”
The
extremely inverse
time
overcurrent
unit
is
the
watt-metric
type.
The
upper
portion
of
the
iron
structure
has
two
concentric
windings on
the middle
leg
of
the
magnetic
circuit.
One
of
these
is
a tapped
operating
current
winding
connected to
tap
points
on
a
tap
block.
The
other
is
a
floating
winding which
is connected
in
series
with
a
resistor
(and
capacitor
on the
extremely
inverse
units)
and
the
two
coils
on
the
lower
legs
of
the
magnetic circuit.
This
floating
circuit
is
connected
to
a
contact
of
the
auxiliary
unit
hA.H
In
both
types
of
time
overcurrent
units
the
disk
and
shaft
assembly
carry
the
moving
contact
which
completes
the
trip
circuit
when
it
touches
the stationary
contact.
The
shaft
is
restrained by a
spiral
spring
to
give
the
proper
contact closing
current
depending
on tap
setting, and
its
motion
is retarded
by
an
Plnico
drag macnet,
which
acts
on
the
disk
to
produce
the
desired
time
characteristic.
The
lower
bearing
for
the
shaft
assembly
consists
of
a
polished
pin
driven
into
the
shaft
and
riding
on a
sapphire
jewel,
spring
mounted
in
a screw-type
assembly.
The
upper
bearing
consists
of
an adjustable
pivot
assembly
mounted on
the
frame
and
having
a
polished
pin
which
projects
into
a
bronze guide
ring
located
at the
top
of
the
shaft.
The
variable
retarding
force
resulting
from
the
gradient of
the spiral
spring
is
compensated
by
the
spiral
shape
of
the
induction
disk.
This
results
in
an increased
driving force as
the
spring
winds
up.
A calibrated
time
dial
determines the
distance
of
travel
of the
moving
contact,
thus
controlling
the
pickup
time.
Each
of
the
instantaneous
overcurrent
units
is of
the
plunger-type
construction.
The
adjustable
armature
is
mounted
on the
threaded
portion
of a
plunger
rod
which
carries
the
moving
contacts
upward
as
the
armature is
operated.
The
armature
is
drawn
upward
into
the
coil
by
the
flux created
in
the
rectangular
magnet
frame
and
a
cylindrical
pole
piece
inside
the
coil.
Guides
for
the
plunger
rod are
provided
at the
4

GEK—65573
top
by
a
hole
in
the pole
piece,
and at
the bottom
by the fit
of
the
molded
contact
carrier
inside
the
calibration
Lube.
Openings
in
the
sides
of
the
calibration
tube
allow
access
to
the
armature
to
adjust
pickup.
The
auxiliary
unit
‘A”
is
a
telephone—type
relay.
The
construction
of
a
typical
telephone-type
relay
is shown
in
Fig.
11.
The
components
of
each
relay
are
mounted
on
a
cradle
assembly
which
can
be
easily
removed from
the
relay
case.
The
cradle
is
locked
in
the
case
by
means
of
latches
at
the
top
and
bottom.
The
electrical
connections
between
the
case
blocks
and
cradle
blocks
are
completed
through
removable
connection
plugs.
Separate
testing
plugs
can
be
inserted
in
place
of
the
connection
plugs
to permit
testing
the
relay
in its
case.
The
cover
is
attached
to
the
case
from
the front
and
includes
an
interlock
arm
which
prevents
the
cover
from
being
replaced
until
the
connection
plug
has been
inserted.
RATINGS
TIME
OVERCURRENT
UNIT
Ratings
of
the
time
overcurrent
unit
are
given
in
Table
I.
TABLE
I
PICKUP
RANGE, AMPERES
FREQUENCY
MAIN
(TIME)
INSTANTANEOUS
RELAY
CYCLES
UNIT
UNIT
0.5
-
4.0
IAC6OT
60
2.0
-
16.0
________
J
2—50
IAC8OT
0.5
-
4.0
60
IAC9OT
1.5
-
12.0
Available
taps
for
time
overcurrent
units
are
shown
on
Table
LI
TABLE
II
RANGE
AMPERES
TAPS
AVAILABLE
(AMPERES)
0.5
-
4.0
0.5,
0.6, 0.7, 0.8,
1.0,
1.?,
1.5, 2.0, 2.5, 3.0,
4.0
1.5
—
12
1.5,
2.0,
2.5, 3.0,
4.0,
5.0,
6.0, 7.0,
8.0,
10.0,
12.0
2.0 -
16
2.0,
2.5,
3.0, 4.0,
5.0,
6.0, 7.0,
8.0,
10.0,
12.0,
16.0
5

SEK-65573
The
one—second
thermal
ratinqs
are
listed
in
Table
III
TABLE
III
RELAY
RANGE
ONE-SECOND
MODEL
(AMPS)
RATING
(AMPS)
IAC6OT
0.5
-
4
70
2
- 16
260
0.5
- 4
140
IAC8OT
1.5-12
260
0.5
- 4
125
IAC9OT
1.5
- 12
260
For
ratings
of
less
than
one
second,
the
rating
may
be calculated
according
to
the formula
I
=./i,
where
T
is
the
time
in
seconds
that
the
current
flows. T
The continuous
ratings
for
the
various
taps
of each
model and
current
range
are
given
in
Tables
IV,
V and
VI.
CONTINUOUS
0.5
-
4.0
AMP RANGE
TABLE
IV
RATING
OF
0.5
- 4.0
AMP TOC
UNITS
MODEL
TAP
0.5 0.6
0.7
0.8
1.0
1.2
1.5
2.0
2.5
3.01
4.0
IAC6OT 1.6
1.8
2.0
2.1
2.3 2.7
3.0
3.5
4.0
4.5
5.0
IAC8OT
4.0
4.5 5.5
5.5 6.0 7.0
7.5
9.0
10.0
11.0
13.0
IAC9OT
3.5
3.7
4.0
4.5 5.0 5.5
6.0
7.0
8.0
9.0
10.0
6

GEK—65573
TABLE
V
CONTINUOUS
RATING
OF
1.5-
12.0
AMP
TOC
UNITS
1.5
-1?.O
AMU
RANGE
MODEL
TAP
1.5
2.0
2.5
3.0
4.0 5.0
6.0
7.0
8.0
10.0
12.0
IACBOT
RATING
10.0
11.5
13.0
14.5 17.0
19.0
21.0
23.0
23.5
27.5
30.5
(AMPS)
IAC9OT
9.5
10.5
11.5
12.5
14.0
15.5
17.0 18.0 19.0
20.0
20.0
TABLE
VI
CONTINUOUS
RATING
OF 2
-
16.0
AMP
TOC
UNITS
2
-
16.0
AMP
RANGE
MODEL
TAP
2.0 2.5
3.0
4.0
5.0 6.0
7.0
8.0
10.0
12.0
16.0
RATING
IAC60(AMps)
8.0
9.0
10.0
12.0 14.0 15.0 16.0
17.5
20.0 20.0
20.O
INSTANTANEOUS
OVERCURRENT
UNIT
These
coils
are
suitable
for
dc
and
frequencies
from
25
to
60
hertz.
The
coils
are
rated
for
five
amperes
continuous
and
have
a
one-second
rating
of
260
amperes.
The
instantaneous
unit
has
a range
of
2
to
50 amperes.
Tap
settings
are
made
per
Table
VII
TABLE
VII
Topof
Relay
LINK POSITIONS
2
12.5
12.5
Pickup
3.?
8
20
Amperes
5
12.5
31.3
(Calibration
8
20
50
Marks)
j__________________________
7

GEK-65573
AUXILIARY
UNIT
The
auxiliary
unit
“A”
has
a
dual
dc
voltaqe
rating of
48/125
volts.
CONTACTS
The
contacts
of
both
the
time
overcurrent
and
instantaneous
units
will
close and
carry
30
amperes
dc
momentarily
for
tripping
duty
at
control voltages
of
250 V dc
or
less.
The
breaker
trip
coil
circuit
should,
however,
always
be
opened
by
a
circuit
breaker
auxiliary
switch
or
other
suitable
means. If
the
tripping
current
exceeds
30
amperes,
an
auxiliary
tripping
relay
should
be
used.
B
(JR
DENS
TIME
OVERCURRENT
UNIT
Burdens
for
the
inverse
time
overcurrent
unit
(IAC6OT)
are
given in
Table
VIII.
TABLE
VIII
BURDENS
AT
MIN.
BURDENS IN
VA
AT
5
AMPS
PICKUP MIN.
TAP
OHMS
(7) CALCULATED
FROM
3
10 20
IMPEDANCE
AT
MIN. TIMES TIMES TIMES
MINIMUM
PICKUP
RANGE
HZ
TAP
R
Z
PICKUP PICKUP
PICKUP
(127)
0.5-
4.0
60 0.5
5.60
21.0 22.0
10.80
5.00
3.66
550.0
.O-16.O
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
pickup
current
(tap
rating)
varies inversely
(approximately)
as
the square
of
the
tap
rating.
For
example,
for
a
relay
with
0.5-4.0
amp
range,
the
impedance
of
the
0.5
ohm
tap is
given
as
22.0
ohms. The
impedance
of
the
2.0 amp
tap
at
2.0
amperes
is
(0.5/2)2
x
22
=
1.37
ohms.
Burdens
for
the
very
inverse
time overcurrent
unit
(IAC8OT)
are
given
in
Table IX.
TABLE
IX
BURDENS
AT
MIN.
BURDENS
IN
VA
AT
5
AMPS
PICKUP_MIN.
TAP
OHMS
(7) CALCULATED
FROM
3
10
20
IMPEDANCE
AT
MIN.
TIMES
TIMES TIMES
MINIMUM
PICKUP
RANGE
HZ
TAP R
7 PICKUP PICKUP
PICKUP
(12Z)
0.5- 4.0
60
0.5
1.40
3.90
4.15
4.20
2.90
2.20
104.0
1.5—12.0
60
1.5
0.23
0.53 0.58
0.58
0.36
O.?8
14.5
8

____
The
impedance
values
given
are
those
for the
minimum
tap
of
each
relay.
The
impedance
for
other taps
at
pickup
current
(tap
rating)
varies
inversely
(approximately)
as
the square
of
the
tap
rating.
For
example,
for
a
relay
with
0.5-4.0
amp
ranqe,
the
impedance
of
the
0.5
ohm
tap
is
given
as
4.15
ohms.
The
rnpedance
of
the
2.0
amp
tap
at 2.0
amperes
is
(0.5/2)2
x
4.15
0.26
ohm.
Burdens
for
the
extremely
inverse
time
overcurrent
unit
(IAC9OT)
are
given
in
Table
X.
TABLE
X
BURDENS
AT
MIN.
BURDENS
IN
VA
AT
5
AMPS
PICKUP
MIN.
TAP
OHMS
(Z)
CALCULATED
FROM
3
10
20
IMPEDANCE
AT
M1N.
TIMES
TIMES
TIMES
MINIMUM
PICKUP
RANGE
HZ
TAP
R
Z PICKUP
PICKUP
PICKUP
(1 2 Z)
0.5-
4.0
60
0.5
0.80
1.38
1.60
1.60
1.60
1.60
40
1.5-12.0
60
1.5
0.085
0.147
0.17
0.17
0.17 0.17 4.25
The
impedance
values
given
are those
for
the
minimum
tap of
each
relay.
The
impedance
for
other
taps
at
pickup
current
(tap
rating)
varies
inversely
(approximately)
as the
square
of
the tap
rating.
For
example,
for
a
relay
with
0.5-4.0
amp range,
the
impedance
of
the
0.5 ohm
tap
is
given
as
1.60
ohms.
The
impedance
of
the
2.0 amp
tap
at
2.0 amperes
is
(0.5/2)2
x
1.60
=
0.10 ohm.
The
auxiliary
unit
milliamperes
at
48
VDC.
a
battery
drain
of
35.7
coil has
a
resistance
of
2500
ohms
and
a
battery
drain
of
1.92
A
1000 ohm
series
resistor
is
added
for
125 VDC
operation
with
milliamperes.
GEK—65573
NOTE:
NOTE:
INSTANTANEOUS
OVERCURRENT
UNIT
Burdens
for
the
instantaneous overcurrent
unit
are
given
in
Table
IX.
TABLE
XI
AUXILIARY
UNIT
9

GEK-65573
CHARACTERISTICS
TIME
OVERCURRENT
UNIT
Pickup
of
the
time
overcurrent
unit
is
defined
as
the
current
required
to
close
the
contacts
from
the
0.5
time-dial
position.
The
pickup
value
is
within
three
percent
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
percentage
of
the
minimum
closing
value
of
current
that
the
unit
will
reset
is:
IAC6OT
-
90
percent
IAC8OT
-
80
percent
IAC9OT
-
85
percent
The
time
to
reset
to
the Number
10
time-dial
position,
when
the
current
is
reduced
to
zero,
is
approximately:
IAC6OT
-
7
seconds
IAC8OT
-
60
seconds
IAC9OT
-
57
seconds
The
time-current
characteristics
are
shown
in
Fig.
6,
7 and
8 for
the
IAC6OT,
IAC8OT
and
IAC9OT,
respectively.
INSTANTANEOUS
OVERCURRENT
UNIT
The
instantaneous
overcurrent
unit is
continuously
adjustable
over
a
25:1
range.
Pickup
is
set
by adjusting
the
vertical
position
of
the
armature
relative
to
the
markings
on
the
calibration
tube.
The
instantaneous
unit
will
reset
to
the
de—
energized
position
between
85 and
95 percent
of its
pickup
setting.
RECEIVING,
HANDLING
AND
STORAGE
These
relays,
when
not
included
as
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
Apparatus
Sales
Office.
Reasonable
care
should
be
exercised
in
unpacking
the
relay
in order
that
none
of
the
parts
are
injured
or 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.
10

GEK—65573
ACCEPTANCE
TESTS
Immediately
upon
receipt
of
the
relay
an
INSPECTION
AND
ACCEPTANCE
TEST
should
be
made
to
ensure
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
acceptance
tests
at
the
discretion
of
the
user.
Since
most
operating
companies
use
different
procedures
for
acceptance
and
installation
tests,
the
following
section
includes
all
applicable
tests
that
may
be
perlormed
on
these
relays.
VISUAL
INSPECTION
Check
the
nameplate
stamping
to
ensure
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
the
screws
are
tight.
MECHANICAL
INSPECTION
Time
Overcurrent
Unit
There
should
be
no
noticeable
friction
when
the
disk
is
rotated
slowly
clockwise.
The
disk
should
return
by
itself
to
its
rest
position.
Make
sure the
control spring
is
not
deformed
nor
its
convolutions
tangled
or
touching.
Instantaneous
Overcurrent
Unit
The
plunger
assembly
should
exhibit
no
tendency
to
bind
when
operated
by
hand
and
the
movable
contact
arms
must
be
securely
fastened
to
the
molded
contact
support.
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
THE
CT
SECONDARY
CIRCUITS
FROM
BEING
OPENED.
DRAWOUT
RELAY
TESTING
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
shorting
bars
in
the
case.
The
12XLA12A
test
plug
may
also
be
used.
Although
this
test
plug
allows
greater
11

GEK-65573
testing
flexibility,
it
requires
CT
shortinq
jumpers
and the
exercise
of
greater
care,
since
connections
are made
to
both
the relay
and the
external
circuitry.
POWER
REQUIREMENTS
GENERAL
All
alternating
current
operated
devices
are
affected
by
frequency.
Since non-
sinusoidal
waveforms
can he
analyzed
as
a
fundamental
frequency plus
harmonics
of
the
fundamental
frequency,
it
follows
that alternating
current
devices (relays)
will he
affected
by
the applied
waveform.
Therefore,
in order
to
properly
test
alternating
current
relays, it
is essential
to
use
a
sine
wave of
current
and/or
voltage.
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,
R—L
or RC networks,
or
saturating
electromagnets
(such
as time
overcurrent
relays)
would
be
essentially
affected
by
non-
sinusoidal
waveforms.
TIME
OVERCURRENT
UNIT
Rotate the
time dial
slowly
and
check
by
means
of
a lamp
that the
contacts
just
close
at the zero
time
dial
setting.
Where 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
setting,
there
should be
sufficient
gap
between
the
stationary
contact
brush
and
its metal
backing
strip
to
ensure
approximately
1/32
inch
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
of the relay
while
in
the
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
Fig.
2.
The
ring
may be turned
by
inserting
a screwdriver
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
of
the
tap—plug
setting.
The
unit
resets
at
90 percent
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
predetermined
value.
The contacts
are
1?

GEK-65573
just
closed
when
the
dial is
set
on
zero.
When
the
dial
is set
on 10, the
disk
must
travel
the
maximum
amount
to
close
the
contacts
and
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
tiiiie
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
Set the
relay
at
the
0.5
time-dial
position
and
2.0
ampere
tap.
Using
the
test
connections
in
Fig.
13,
the main
unit
should
close
its
contacts
within
plus
or minus
two
percent
of
tap
value
current.
Time
Test
Set
the
relay
to
the
No.
5
time—dial
position
and
the
2.0
ampere
tap.
Using
the
test
connection
in
Fig.
13,
apply
five
times
tap
current
(10.0
amperes)
to
the
relay.
The
relay
will
operate
and
the
timing
should
be within
the
limits
in
Table
XII.
TABLE
XII
RELAY
TIME
IN SECONDS
IAC6OT
1.73
-
1.83
IAC8OT
1.27 1.35
IAC9OT
0.89
-
0.95
INSTANTANEOUS
UNIT
Pickup
and
Reset
The
units
are normally
supplied
from
the
factory
with
the
bottom
of
the
armature
aligned
with
the
top
mark
on
the
calibration
tube.
This
corresponds to
the
minimum
pickup
settinq
on
the
nameplate.
It
should
be sufficient
to
check
the
pickup
of each
unit
at this
setting,
see
Fiq.
14.
With
gradually increasing
test
current
in the
operating
coil
the
unit
should
pick
up,
closing
its
normally
open
contacts
with
one
continuous
motion,
at
the
calibration
current
level.
The
test
current
should
then
be
gradually
decreased
until
the
contacts
reset.
The
reset
value
should
be
between
85
and
95 percent
of
pickup.
AUXILIARY
UNIT
The
relays
are
normally shipped
from
the
factory
with
the
coil
circuit
of
unit
HAN
connected
for
the
lower
value
of
the
dc
voltage
rating
shown
on the
nameplate.
Apply
60
percent
of
the
lower
voltage
rating
across
terminals
9
and
10
and
check
that
unit
“A”
picks
up
and
wipes
in with
one
continuous
motion
of the
armature.
13

GEK—65573
INSTALLATION
The
relay
should
be
installed in
a
clean,
dry
location, free
from
dust,
and
well
lighted
to
facilitate
inspection
and
testinq.
The
relay
should
be
mounted
on
a vertical surface.
The
outline and
panel
drilling
is
shown
in Fig.
15.
The
internal
connection
diagrams
for
the
relays
are
shown
in
Fig.
4
and
5.
Typical
external
connections
are
shown
in Fig.
10.
INSTALLATION TESTS
The
following
tests
are
to
be
performed
at
the
time
of
installation:
Time
Overcurrent
Unit
1.
Set
tap
screw
on
desired
tap.
Using
the
test
circuit
in Fig.
13,
apply
approximatley
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
two
percent
of
tap
value.
2.
Check
the
operating
time
at some
multiple
of
the tap
value. This
multiple
of
tap
value
may be
five
times
tap
rating
or
the
maximum
fault
current
for
which
the
relay
must
coordinate.
The
value
used
is
left
to
the
discretion of
the
user.
Instantaneous Unit
1.
Set
the
desired
tap
range.
2.
Set
the
pickup
by
turning
the
bottom
of
the
knurled
armature
to
the
approximate
position
in
the
calibration
tube
corresponding
to
the
desired
pickup
setting.
3.
Gradually
apply
current
and
adjust
the
armature
as
required
for
the correct
pickup
(see Fig.
14).
4.
Check
that
the
instantaneous
unit
resets
between
85 and
95
percent
of
pickup.
Auxiliary
Unit
The
operating
coil
circuit
of
the
auxiliary
unit
“A”
has
a
dual
dc
rating
as
shown
on
the
relay
nameplate.
As
shipped
from
the factory the
unit
is
connected
for
the
lower
of
the
two
dc
voltage
ratings.
If
it
is
desired
to
operate
the
unit
at
the higher
dc
voltage,
the
leads
to
terminal
points
9
and
9A
should
be interchanged
so
that
resistor
Ri
is
in
series
with
the
auxiliary unit
coil.
Refer
to
the
internal
connection
diagrams,
Fig.
4
and
6.
14

GEK—65573
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
sugqested
that
the
points
listed
below
he
checked
at
an
interval
of
from
one
to two
years.
These
tests
are
intended
to
insure
that
the
relays
have
not
deviated
from
their
original
settings.
If deviations
are
encountered,
the
relay
must
be retested
and
serviced
as
described
in
this
manual.
TIME
OVERCURRENT
UNIT
1.
Perform
pickup
tests
as
described
in
the
INSTALLATION
section
for
the tap
setting
in
service.
2.
Perform
the
time
tests
as
described
in
the
INSTALLATION
section.
INSTANTANEOUS
UNIT
Check
that
the
instantaneous
unit
picks
up at
the
desired
current
level,
as
outlined
in
the
INSTALLATION
section.
AUXILIARY
UNIT
Check
that
the
auxiliary
unit
operates
when
voltage
is
applied,
as
outlined
in
the
INSTALLATION
section.
CONTACT
CLEANING
For
cleaning
relay
contacts,
a
flexible
burnishing
tool
should
be
used.
This
consists
of
a
flexible
strip
of
metal
with
an
etched—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.
The
flexibility
of
the
tool
insures
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
TAC
relay,
overall
functional
tests
to
check
the
system
operation
are
recommended
at
intervals
based
on
the
customer’s
experience.
15

GEK-65573
SERVICING
IF
any
of
the
mechanical
or
electrical
check
points described
in the previous
sections
are found
to be out
of
limits, the
followino
points
should
be
observed
in
restoring
them.
MECHANICAL
ADJUSTMENTS
Time Overcurrent
Unit
1.
Contact
Adjustment
The
contacts
should
have
aprroximately
1/3? inch
wipe. That
is,
the stationary
contact
tip should
be
deflected
about
1/32 inch
when
the
disk
completes
its
travel.
The contact
wipe is
adjusted
by turning
the
screws in
the
contact
brush
which
regulate
the
position
of
the brush
relative
to
the
brush
stop.
When
the
time
dial
is moved
to the
position
where
the contacts
just
close,
the
time-dial scale
should
indicate
zero. If
it
does not
and the
brushes
are
correctly
adjusted,
regulate
the
dial
to
read
zero.
This is done
by
changing
the
position
of
the arm
attached
to the
shaft,
which
is located
below the
time dial.
Loosen
the
screw
which
clamps
the
arm
to
the
shaft
and
turn the
arm relative
to
the
shaft
until
the contacts
just make
for
zero
time—dial
setting.
The leaf
spring
on
the
stop
arm should
be
so formed
that there
is approximately
1/64
inch
deflection.
The deflection
can be increased,
if
necessary,
by forcing
a
thin
screwdriver
blade
between
the leaf
spring
and
the
stop
arm.
2.
Shaft
End
Play
End play
is
determined
by
the relative
positions
of the
lower
jewel
bearing
and
upper
pivot.
Both
bearing
and pivot
are held
in
position
by
means
of set
screws
in
the die-cast
supporting
frame.
The lower
jewel
must be
located
so that
the
disk
is
approximately
centered
in
the air gaps
of the
driving
magnet
and
the drag
magnet.
The
upper
pivot
should then
be
located
so that the
shaft
has
1/64
inch
to
1/32
inch
end
play. Be
sure
that both
set screws
are securely
tightened
after the
adjustment
is completed.
3.
Friction
If
a tendency
to
bind
or excessive
friction
is evident,
first
check
for
obstructions
to
the disk
travel.
Dirt or
metallic
particles
in
the wattmetric
or
drag
magnet
gaps
can
interfere
with
the
motion of
the disk.
Instantaneous
Unit
1.
Friction
If
there is
any
tendency
to
bind
or
excessive
friction
is
present,
check to
see
that
the moving
contact
guide pin
is centered
and moves
freely
in the
U-shaped
guide
plate
slot, and
that no
foreign
matter
is present
between
the
armature
and
calibrating
tube.
16

GEK-65573
2. Moving
Contact
Leads
The
flexible
moving
contact
leads
should
be
formed
to
keep
the
moving
contact
assembly
centrally
located.
If
these
moving
contact
leads
have been
deformed,
they
should
be
reshaped
as follows:
the
insulated
portion
of
the
lead
should
extend
straight
back
to
the
slot
in
the
compound
mounting
plate.
There
should
be
a
90—
degree
bend
in
the
lead
at
a
point
just
beyond
the
end
of
the
insulating
sleeve,
and
the
bare
lead
should
project
either
up or
down
to the
terminal
screw.
ELECTRICAL
ADJUSTMENTS
Time
Overcurrent
Unit
1.
Pickup
Adjustments
The
current
at
which
the
contacts
operate
is
normally
controlled
by
means
of
the
tap
screw
in
the
tap
block
at
the
top
of
the
unit.
The
tap
screw
should
be
screwed
firmly
into
the
tap
position
marked
with
the
desired
pickup
current.
Note
that
if
the
relay
is
in
service
the
tap
screw
must
not
be
removed
until
the
relay
connection
plugs
have
been
withdrawn.
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 screwdriver
in
the
notches
around
the
edge.
By turning
the
ring,
the
operating
current
of
the
unit
may
be
brought
into
agrenent
with
the
tap
setting
employed,
if
for
some
reason
this
adjustment
has
been
disturbed.
This
adjustment
also
makes
possible
any
desired
setting
between
the
various
tap
settings.
The
unit
is
adjusted
at
the
factory
to
close
its
contacts
from
any
time—dial
position
at
a
minimum
current
within
five
percent
of
the
tap
plug
setting.
In
making
pickup
checks,
use
the
connections
of Fig.
13.
Note
that
the
“A” unit
contacts
must
be closed
during
tests.
2.
Pickup
Time
Adjustments
Normally
pickup time
is
controlled
by
means
of
the
time
dial
at
the
top
of the
unit.
If
the
pickup
time
for
a
particular
time—dial
setting
and
pickup
multiple
is found
to
be
outside
the
limits
mentioned in
ACCEPTANCE
TESTS
and
PERIODIC
CHECKS,
it
can
be
restored
by
changing
the
position
of
the
drag
magnet
on
its
supporting
shelf.
Moving
the
magnet
towards
the
shaft
decreases
the time
while
moving
it
away
from
the
shaft
increases
the
time.
If
the
drag
magnet
is moved
towards
the
shaft,
be
sure
that
in
its
final
position
is
clears
the
counterweight
on the
disk
for
all positions
of
the
disk
and
shaft
assembly.
If
the
magnet
is
moved
away
from
the
shaft,
its
outer
edge
must
be at
least
1/8
inch
from
the
edge
of the
disk
at
the
smallest radius
of
the
disk.
Instantaneous
Unit
Refer
to
the
INSTA[LATION
section
for
current
pickup
adjustments.
17

GEK-65573
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
damacjed.
When
ordering
renewal
parts,
address
the
nearest
Sales
Office
of
the
General
Electric
Company,
specify
quantity
required,
name
of
the
part
wanted,
and give
complete
model number
of
the
relay
for
which
the
part
is
required.
18

GEK—65573
LIST OF
FIGURES
PAGE
Fiq.
1
JAC6OT Relay,
Front
View
19
Fig.
2
IAC6OT
Relay,
Rear
View
20
Fig.
3
IAC9OT Relay, Rear
View
21
Fju.
4
JAC6OT
and
TAC80T Internal
Connections
22
Fig.
5 IAC9OT
Internal Connections
23
FiQ.
6 Inverse
60 Hertz
Time
Curves
24
Fig.
7 Very
Inverse 60 Hertz
Time Curves
25
Fig.
8
Extremely
Inverse
60
Hertz
Time
Curves
26
Fig.
9
Instantaneous
Unit Time
Curves 27
Fig.
10 External
Connections
28
Fig.
11 Auxiliary
Unit
29
Fig.
12
Cross
Section
of
Drawout
Case Connections
30
Fig.
13
Test
Connections -
Time Overcurrent Unit
31
Fig.
14 Test
Connections - Instantaneous
Unit
32
Fig.
15
Outline and
Panel
Drilling
33
19

GEK—65573
Fig.
1 (Later)
IAC6OT
Relay,
Removed from Case, Front View
20