GE 12IAC8OL User manual

INSTRUCTIONS
Insert
Booklet-
GEH-1788
TIME
OVERCURRENT
RELAY
TYPE
TAC
MODEL
12IAC8OL(-)A
INTRODUCTION
This
supplement
in
conjunction
with
GEH—1788
forms
the
instructions
for
relay
model
12IAC8OL(-)A.
DESCRIPTION
Relay
model
12IAC8OL(-)A
consists
of
a
single
IAC
type
time
overcurrent
unit
with
a
seal—in
unit
mounted
in
a
small
single
ended
(Si)
case.
This
relay
is
similar
to
model
121AC53A(-)A
described
in
GEK-1788
except:
1)
The
internal
connections
are
as
shown
in
figure
1
of
this
supplement.
2)
The
induction
unit
uses
wound
shading
coils
on
the
U-magnet
to
provide torque
control.
This
control
circuit
(connected
to
studs
3
and
4)
must
be
completed
in
order
that
there
be
a
phase
displace
ment
in
flux
to
rotate
the
disk.
When
the
shading
coil
circuit
is
completed,
torque
can
be
developed
on
the
induction
disk
and the
unit
will
operate
on
overcurrent.
When
the
shading
coil
circuit
is
open,
the
unit
will
not
operate
at current
levels
up
to
20
times
tap
value.
The
time
current
curves,
burdens
and
ratings
of
this
relay
are
as
given
in
GEH-1788
for
model
121AC53A(-)A.
Those
Instructions
do
not
purport
to cover
all
detafle
or
variation.
in
equip..nt
nor to
provide
for
every
possible
contingency
to
be
met in
connection
with
inatal3atioq,
operation
or
.aintenanc..
Should
further
information
be
desired
or
should
particular
probls
arise
which
are
not
covered
•ufficiently
for
the
purchaser’s
puro.ea,
the
matter
should
be
referred
to
the
General
Liectric
Company.
POWER
SYSTEMS
MANAGEMENT
DEPARTMENT
GENERAL•
ELECTRIC

GEK- 27870
*
=
SHORT
FINGERS
CONTROL
WINDINGS
C)
6
FIG.
1
(0226A7211-0)
INTERNAL
COKNECTIONS
DIAGRAM FOR THE
IACBOL(-)A
RELAY
(FRONT
VIEW)
GENERAL
ELECTRIC
CO..
POWER
SYSTEMS
MANAGEMENT BUSINESS
DEPT.,
MALVERN,
PA.
19355
SEAL—IN
1
3
24
8-70

INSTRUCTIONS
GEH-1
788L
TYPES
TIME
OVERCURRENT
RELAYS
GENERAL
ELECTRIC
IAC53A
IAC53B
IAC53C
IA
C5
3 R
IAC54A
IAC54B

c’1
c..J
c..1
Di
LL
cS-i
LC)
C’,
0
>
0
C-,
GEH-1788
Tvne
IAC
Time
Overcurrent
Relay
TOP
PIVOT
TAP PLUG
SEAL-IN
UNIT
HOLDING
(0I
L
SEAL-
IN
TARGET
SEAL-IN
--
UNIT
STATIONARY
CONTACT,
FT
S[AL
N
UNIT
STATIONARY
CO
N
TA (.T
RIGHT
SEAL
IN
MOVING
CON
TACT
AC
3EMBLY
TAP
BLOCK
--TIMF
DIAL
DISK
SHAFT
MAIN
MOVING
CONTACT
M A
N
STA’
IDNARY
ROUGH
AND
CONTACT
ASS
C
MB
L
Y
MAGNET
0151<
(ii
Si,p,
—
-‘p
‘4
Fiq.
I
The
Induction
Unit
for
Type
IAC
Relays
(Front
View)
DISK
AND
SHAFT
—
JEWEL
SCREW
Fin.
2
The
Induction
Unit
for
Type
IAC
Relays (Rear
View)
2

TIME
OVERCURRENT
RELAYS
TYPE
IAC
INTRODUCTION
The
Types
1AC53
and
1AC54
relays are
time
overcurrent
relays
with
a
very-inverse
time
char
acteristic.
They
are
employed
to
protect
against
overcurrent
on
single-phase
and poly-phase
circuits.
The
various
relays
described
in
this
instruction
book
differ
in
the
number
of
circuits
they
close,
and if
an
instantaneous
unit
and/or
an
a-c
tripping
unit
is
included.
These
relays
consist
of
an induction unit
or
an
induction
unit
with
an
instantaneous
unit
which
per-
mits
instantaneous
tripping
for
exteremely
high
cur
rents,
or
an
induction
unitwithana-c
tripping
unit for
use
where
d-c
power
is unavailable or
a-c
tripping
is
preferred.
Since
practically
all
Type
IAC
relays
are
composed
of
various
combinations
of
the
above
(that
is,
the
induction
unit, the
instantaneous
unit
and the
a-c
tripping
unit),
they
are,
for convenience,
describ
ed
separately
in
the
following
text.
The
above
table
indicates
the
units
comprising
each
type
and
also
lists
the
internal
connections
and
outline
andpanel
drilling
diagrams.
INDUCTION UNIT
INTRODUCTION
The
induction unit
is
the
basic
unit
in
all
Type
TAC
relays.
Figs.
1
and
2
show
the
induction
unit
mounted
in
the
cradle.
These
units
are
of
the
induc
tion-disk
construction
type.
Thediskisactuatedby
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
station
ary
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
seal-in
unit
mounted
on
the
front
to
the
left
of
the
shaft.
This
unit
has
its
coil
in
series
and
its contacts
in
parallel
with the main
contacts
such
that
when
the main
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.
APPLICATION
The
induction unit
is
the
main
unit
in
all
Type
IAC
relays,
supplying
the
very
inverse
time
delay
characteristics
of
the
relay
and
soundingan
alarm
or
tripping
the
breakers
for overload
currents
which
cause
it
to close its contacts.
OPERATING
CHARACTERISTICS
The
induction
unit
may
have
one
or two
circuit-
closing
contacts
which
close
as
the
current increases
to
the pick-up
value
as set on the
tap
block. The
time
delay
in closing
the
contacts
is determined
by
the
setting
of the
time
dial
(Fig.
1).
The
time-cur
rent
characteristics
are
shown
in
Fig.
3.
RATINGS
The
induction
unit
is
designed
to use
any
one
of
four
operating
coils,
each
having
a
different
com
bination
of
taps
as
follows,
4,5,6,7,8,10,12,
and
16
amperes;
1.5,2.0,
2.5,
3.0, 4.0,
5.0
and
6.0
amperes;
0.5, 0.6,
0.8,
1.0,
1.2,
1.5
and
2.0
amperes;
0.1,
0.12,
0.16,
0.2,
0.24,
0.3
and
0.4
amperes.
T
Contact
Instan.
A-C
Trip
Induc.
Outline
mt.
ype
Circuits
Unit
Unit
Unit
&P.
D.
Conn.
IAC53A(-)A
One
No
No
One
Fig.
20
Fig.
12
IAC53B(-)A
One
Yes
No
One
Fig.
20
Fig.
13
IAC53C(-)A
One
No
Yes
On
Fin.
20
Fig.
14
iAC53R(-)A
One
Yes
Yes
One
Fig.
20
Fig.
15
IAC54A(-)A Two
No
No
One
Fig.
20
Fig.
16
1AC54B(-)A
Two
Yes
No
One
‘Fig.
20
Fig.
17
Shove
instructions
do
not
purport
to
cover
al.!
details
or
variations
in
equipment
nor
to
provide
for
n’Jer
posszble
contingency to
be
met
in
connect
ion with
installation,
operation
or
rrintenance.
Should
rurt;2-O-
information
he
des;rcd
or
should
particular
problems
arise
which
are
not
covered
sufficiently
for
the
pur.:lianer
‘s
purposes,
the
matter
should
be
referred
to
the General
Electric
Company.
To
Civ
Cxtent
requlred
the
products
described herein
meet
applicable
ANSI,
IEEE
and
NEMA
standards; but
no
such
ssura.nce
is
qiven
with
respect
to
local
codes
and
ordinances
because
they
vary
greatly.
3

GEH-1788
Type
[AC
Time
Overcurrent
Relay
:
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Figure
3 (0888e0270
[3])
Time-Current
Curves
for
Type
IAC
Relays
with
Very-Inverse-Time
Characteristics
I
$
44
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III
MULTIPLES
OF RELAY
TAP SETTING
I
I I
fiiiij
4

Type
IAC
Time Overcurrent
Relay
GEH-1788
CALIBRATION
PLATE
ADJUSTABLE
I-.---- POLE PIECE
MS
TA
N
TA N
EDUS
UNIT
OPERATING
COIL
TARGET
STATIONARY
[
CONTACTS
MOVING
CONTACT
ASSEMBLY
CONTACTS
SHORTING
COIL
BURDENS
The
current-closing rating of the
contacts
is
30
amperes
for voltages
not
exceeding
250 volts.
The
current-carrying
ratings
are
affected
by
the
selection
of
the
tap
on
the target
and seal-in
coil
as
indicated
in the
following
table:
Amperes, a-c
or d-c
Function
2-Amp
Tap
0.2
Amp
Tap
Tripping
Duty
30
5
Carry
Continuously
3
0.3
Operating
Range
2-30
0.2-2
Resistance
0.13
7
Impedance
at 60
cy
0.53
52
If
the
tripping
current
exceeds
30 amperes
an
aaxiliary
relay
should be
used, the
connections
being
such
that the
tripping
current
does
not pass
through
the
contacts
or
the target
and
seal-in coils
of
the
protective
relay.
Burdens
for the
standard coils
are given
in the
following
table. These
are
calculated
burdens
at
five
amperes
based
on burden
of
minimum
tap.
Volt-ampere
burdens
for
the lowest
tap
on
any
of the
three coils
can
be determined
for any
value
of
current,
up
to
20 times
tap setting,
from
Fig.
6.
Coil
I
Volt Imp.
Amps
Freq.
Tap
Amps
Amps Ohms
PF
4-16
60
4
5
2.0
0.08
0.50
50
4
5
1.7
0.07
0.50
25
4 5
1.3
0.05
0.61
1.5-6
60 1.5
5
14.5
0.58
0.42
50 1.5
5
12.0
0.48
0.42
25
1.5
5
9.0
0.36
0.55
0.5-2
60
0.5
5
105.0
4.20
0.35
50
0.5
5
86.0
3.45
0.34
25
0.5
5
82.0 3.28
0.55
60
0.1
5
3050
122
0.38
0.1-0.4
5tJ
0.1
5
2546
102
0.36
INTRODUCTION
INSTANTANEOUS
UNIT
The
instantaneous
unit
is
a small
instantaneous
hinge-type
unit which
may be
mounted
on the
right
front
side
of the
induction
unit
(See
Fig.
4).
Its
contacts
are
normally
connected
in parallel
with
the
contacts
of the
main
unit. Its
coil
is connected
in
series
with the
operating
coil
of the main
unit.
When
the
current
reaches
a predetermined
value,
the
instantaneous
unit
operates,
closing
the
contact
circuit
and
raising
its
target
into
view.
The
target
latches
in
the exposed
position
until
released
by
pressing
the
button
beneath
the
lower
left-hand
corner
of the
relay
cover.
1•-
C’4
C.,’
cc
0,
LL
c..J
C.,’
cc
MAIN
COIL
A
-C
TRIPPING
UNIT
U-
Fig.
L
Type
AC
Relay with
an
Instantaneous
Unit
(Front View)
Fig. 5
Type IAC
Relay
with an
A—C Trip
Unit
(Rear View)
5

GEH-1788
Type
IAC
Time
Overcurrent
Relay
0
24
6
8
10
12
14
16
18
20
MULTIPLES
OF MINIMUM
SATURATION
CURVES
FOR
INDUCTION
UNITS
ON
TYPE
IAC
RELAYS
PIC1(—UP
CURRENT
LOWEST
TAPS
OF
VERY
INVERSE
Fig.
6
Saturation
Curves
for Lowest
Taps
of
tre
Induction
Unit
of
Type
IAC
Re’ays
with
Very—Inverse-Time
Character
i
stics
26
24
22
20
16
14
12
10
8
6
4
2
0
V
0
L
T
A
G
E
z
V
V
;
/Ez
—--
-
-
iEEEEz
—--------
6
0r.,
5Q,,,
25.
6O
50
25
50.-s.,
25
TA
P
RANGE
0.5—2.0
AMPS.
TAP
RANGE
1.5—6.0
AMPS.
-
TAP
.RANGE
4—16
AMPS.
V..
C
C
0
‘a
U-
6

Type
IAC
Time
Overcurrent
Relay
(JEH-1788
0.030
0.025
0.
20
0.015
0.
010
0.005
10
Fig.
7A
(K-6306872
[5).
Time-Current
Characteristics
for Original
Instantaneous
Unit
,I
$I94C
RATD
TMTIRJS
IJIT
Fig. 7B
(0208A869
5-1)
Time-Current
Characteristics
for
the Hi-G”
Unit
c)
LI
Cr,
LI
L)
0
—
&
OPERATING
TIME
—
c—
RANGE
FOR
ANY
PICKUP
SETTING
—
0
0
1
2
3
4
5
6
M.JLTIPLES
OF
PICK—UP
7
89
aILTIPiF
OF
PICOOP
.7

GEH-1788 Type
IAC Time
Overcurrent
Relay
APPLICATION
rhe
instantaneous
unit
is
used
on
certain
Type
IAC relay
models
to
provide
instantaneous tripping
for
current
exceeding
a
predetermined
value.
OPERATING
CHARACTERISTICS
*
The
instantaneous
unit
operates
over
a
four—
to—one
range
and has
its
calibration
stamped
on
a
scale
mounted
beside
the
adjustable
pole piece.
Time—current characteristics
are shown
in
Fig.
7A
for
the
instantaneous
unit used
before
1977.
In 1977 the
instantaneous
unit
was modified to
make it
have
a
higher
seismic
rating. The new
instantaneous
unit
can
be
identified by
the
mark
ing
“Hi—C”
moulded
into the front moulding just
above
the target
windows.
The
time—current
characteristic
for
the
“Hi—C”
unit
is
shown
in
Fig. 7B.
RATINGS
The instantaneous
unit
is
designed
to
use
the
coils
listed
below;
Coil
Freq
Amp
Volt-
Imp.
P.F.
Amp
Ohms
0.5-2
60
- 5
360
14.4
0.74
1-4
60
90
3.6
0.77
2—8
60
5
22.5
0.90
0.83
25
5
8.0
0.32 0.83
4-16
60
5
5.63
0.225
0.87
50
4.77 0.191
0.87
40
5
3.93
0.157
0.88
25
5
2.37 0.095
0.88
7—28
60
5
1.88
0.067
0.88
10-40
60
5
0.83
0.033
0.95
50
5
0.80
0.032
0.95
25
5
0.68 0.027
0.98
20-80
60
5
0.20
0.008
0.95
50
I
5
0.20 0.008
0.95
25
5
0.18
0.007
0.98
A-C
TRIPPING
UNIT
INTRODUCTION
The a-c
tripping
unit is
aType
REA
relay
unit
designed
to
energize
a
circuit-breaker
trip coil
from
its
associated
current
transformer
upon
the
operation
of
the
main
unit
of
the
Type TAC
relay.
It
transfers
the current
from
the
secondary
of
the
current
transformer
into
the
trip
coil
and removes
the
current
from
the
trip coilwhen
the
breaker
trips.
The tripping
unit
is
mounted
on
the
rear
of
the
frame
opposite
the tapped
operating
coil
of
the
in
duction unit
(see
Fig. 5).
The
operation
of
this unit
is
illustrated
in
FIg. 11. The
secondary
current
circulates
through the
Induction
unit
current
coil
and
the
main
coil
of
the
Type REA
auxiliary
tripping
unit,
returning
through
the
Type
REA
contacts
to the
cur
rent transformer.
Normally,
most
of
the flux
gener
ated
by
the
main
Type
REA
coil
passes
through
the
upper limb
of
the magnetic
structure
and
holds
the
armature
firmly
against
this
limb.
When
the
contacts
of
the
induction unit
close,
the
shorting
coil of
the
Type
REA
unit is
short-circuited
and
current
flows
in
this
coil
by
transformer
action, causing
a
redis
tribution
of
flux
which
actuates
the
armature
and the
Type
REA
contacts.
The
opening
of
the
Type
REA
contacts
causes
the
secondary
current
to
flow
through
the
trip
coil
which
trips
the
breaker.
8
*
Indicates
revision