GE IAC57A User manual

GEI
-
19959
J
INSERT
BOOKLET
GEH
-
1753
INSTRUCTIONS
LONG
-
TIME
OVERCURRENT
RELAYS
TYPES
IAC
57
A
and
IAC
57
B
INTRODUCTION
This
booklet
,
with
Insert
Book
GEH
-
1753
,
forms
the
instructions
for
the
Type
IAC
57
A
and
IAC
57
B
relays
.
The
IAC
57
A
and
IAC
57
B
relays
are
similar
to
the
Type
IAC
51
A
and
IAC
51
B
relays
,
respectively
,
except
that
some
of
the
parts
have
been
altered
to
provide
longer
operating
times
.
Typical
time
-
current
curves
for
these
relays
are
shown
in
Figure
1
of
this
booklet
.
The
one
-
second
and
continuous
current
ratings
for
these
relays
are
listed
in
Table
I
.
TABLE I
CURRENT RATINGS
1
-
SECOND
CONTINUOUS
RELAY
RANGE
10.0
-
20.0
5.0
-
8.0
1.5
-
3.5
250
4
-
16
1.5
-
6
0.5
-
2
200
70
The outline
and
panel
drilling
dimensions
for
these
relays
are
shown
in
Figure
20
of
GEH
-
1753
.
The internal
connection
diagram
for
IAC
57
A
is
Figure
11
and
for
IAC
57
B
is
Figure
12
in
GEH
-
1753
.
These
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
.
Courtesy of NationalSwitchgear.com

GEI
-
19959
11
!
irtui
i
HlHffl
«
NM
«
!
m
1
«
I
0
9
8
6
5
o
c
4
3
«
o
o
2
Q
6
h
-
2
i
i
i
mill
I
I
S
I
*
ll
|
m
m
mm
Tinag
MULTIPLES
OF
RELAY
TAP
SETTING
Figure
1
(
0888
B
0272
[
1
]
)
Typical
Time
-
Current
Characteristic
of
Type
IAC
57
Relays
ST
6
/
93
(
300
)
GENERAL
ELECTRIC
METER
AND
CONTROL
BUSINESS
DEPT
.
,
MALVERN
,
PA
19355
Courtesy of NationalSwitchgear.com

GEH
-
1753
J
INSTRUCTIONS
TIME
-
OVERCURRENT
RELAYS
TYPES
IAC
52
A
IAC
52
B
IAC
51
A
IAC
51
B
IAC
51
R
GENERAL
#
ELECTRIC
Courtesy of NationalSwitchgear.com

GEH
-
1753
Time
Overcurrent
Relays
Type
IAC
TOP
PIVOT
TAP
]
BLOCK
TAP
PLUG
SEAL
-
IN
UNIT
HOLDING
COIL
I
V
•
>
•
y
•
©
55
m
%
i
Li
TIME
DIAL
SEAL
-
IN
TARGET
;
m
m
t
&
A
DISK
A
:
i
j
SHAFT
1
SEAL
-
IN
UNIT
STATIONARY
CONTACT
,
LEFT
n
MAIN
!
SI
MOVING
i
§
f
SHAFT
MAIN
STATIONARY
BRUSH
AND
CONTACT
ASSEMBLY
i
!
II
SEAL
-
IN
UNIT
STATIONARY
CONTACT
,
RIGHT
m
/
SEAL
-
i N
MOVING
CONTACT
ASSEMBLY
rR
,
c
11
i
j
i
iL
.
DISK
'
**
*
*
*
*
e
'
STHI
/
CTIOMK
-
s
'
A
;
M
"
(
TAMIL
4
O
’
JS
UNIT
DRAG
MAGNET
m
*
1
'
/
(
8006996
)
Front
View
CRADLE
DISK
AND
SHAFT
COIL
,
MAGNET
,
AND
TAP
1
BLOCK
LASSEMBLY
LOWER
JEWEL
SCREW
B
-
(
8006997
)
Rear
View
Figure
1
.
The
Induction
Unit
for
Type
IAC
Relays
*
2
Courtesy of NationalSwitchgear.com

TIME
-
OVERCURRENT
RELAYS
TYPE
IAC
INTRODUCTION
Contact
Circuits
Instantaneous
Unit
AC
Trip
Outline
&
Panel
Drilling
Induction
Unit
Internal
Connection
Type
Unit
One
One
One
Two
Two
IAC
51
A
(
-
)
A
IAC
51
B
(
-
)
A
IAC
51
R
(
-
)
A
LAC
52
A
(
-
)
A
IAC
52
B
(
-
)
A
No
One
One
One
One
One
Fig
.
11
Fig
.
12
Fig
.
13
Fig
.
14
Fig
.
15
No
Fig
.
18
Fig
.
18
Fig
.
18
Fig
.
18
Fig
.
18
Yes
Yes
No
Yes
No
No
Yes
No
The
Type
IAC
relays
comprise
a
group
of
relays
that
are
employed
to
protect
against
overcurrent
on
single
-
phase
and
polyphase
circuits
.
The
various
relays
in
this
IAC
group
are
identified
by
model
numbers
,
and
the
relays
differ
in
the
number
of
circuits
they
close
,
the
length
of
time
delay
and
features
that
are
determined
by
the
characteristics
of
the
protected
circuit
.
These
relays
consist
of
an
induction
unit
or
an
induction
unit
with
an
instantaneous
unit
which
permits
instantaneous
tripping
for
extremely
high
currents
,
or
an
induction
unit
with
an
a
-
c
tripping
unit
for
use
where
d
-
c
power
is
unavailable
or
a
-
c
tripping
is
preferred
.
Since
practically
all
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
con
-
venience
,
described
separately
in
the
following
text
.
The
above
table
indicates
the
units
comprising
each
type
and
also
lists
the
internal
connections
and
out
-
line
and
panel
drilling
diagrams
.
INDUCTION
UNIT
INTRODUCTION
APPLICATION
The
induction
unit
is
the
main
unit
in
all
IAC
relays
,
supplying
the
inverse
time
delay
character
-
istics
of
the
relay
and
sounding
an
alarm
or
tripping
the
breakers
for
overload
currents
which
cause
it
to
close
its
contacts
.
The
induction
unit
is
the
basic
unit
in
all
IAC
relays
.
Fig
.
1
shows
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
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
.
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
-
current
characteristics
are
shown
in
Fig
.
2
.
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
.
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
.
RATINGS
The
induction
element
is
designed
to
use
any
one
of
three
operating
coils
,
each
having
a
different
combination
of
taps
as
follows
:
4
,
5
,
6
,
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
am
-
peres
.
When
the
These
instructions
do
not
purport
to
cover
all
details
or
variations
in
equipment
nor
to
provide
for
every
possible
contingency
to
be
met
in
connection
with
installation
,
operation
or
maintenance
.
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
.
Should
3
Courtesy of NationalSwitchgear.com

GEH
-
1753
Time
Overeurrent
Relays
Type
IAC
20
\
VS
10
9
rv
\
v
8
Xvs
7
\
\
\
x
8
\
C
/
5
9
Q
\
\
\
X
X
\
2
X
\
V
X
X
N
O
4
\
X
CJ
s
fcd
X
\
\
\
V
X
X
3
3
\
X
X
V
1
\
\
X
x
X
x
V
p
2
\
\
N
V
10
\
9
8
\
v
7
i
\
.
a
6
.
a
«
/
>
\
5
v
.
7
a
>
c
X
4
.
8
X
<
D
3
V
.
4
tn
\
2
V
.
3
O
a
.
2
a
>
E
i
I
-
XI
.
08
.
07
.
08
.
09
.
04
.
03
.
02
.
01
.
3
.
8
.
7
.
8
.
9
1
3
4
8
8
7
8
9
10
20
30
40
SO
80
70
80
SOg
MULTIPLES
OF
RELAY
TAP
SETTING
(
0888
B
0269
[
3
]
)
Time
-
current
Curves
of
Type
IAC
Relays
with
Inverse
-
time
Characteristics
Fig
.
2
.
4
Courtesy of NationalSwitchgear.com

Time
Overcurrent
Relays
Type
IAC
GEH
-
1753
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
:
BURDENS
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
.
3
.
DUAL
RATED
0.2
/
2.0
0.6
/
2.0
2.0
0.2
2.0
0.6
3.5
Carry
30
amps
for
(
sec
)
Carry
10
amps
for
(
sec
)
Carry
continuously
(
amp
)
Minimum
operating
(
amp
)
Minimum
dropout
DC
resistance
60
hertz
impedance
50
hertz
impedance
0.05
2.2
0.5
Coil
Amperes
Volt
-
Amps
Imp
.
Ohms
30
0.45
20
5.0
Freq
.
Tap
PF
0.37
2.3
1.2
2.6
0.2
2.0
0.6 2.0
4
-
16
60
4.0
(
amp
)
(
ohms
)
(
ohms
)
(
ohms
)
0.05 0.5
0.15
8.8
0.5
0.35
0.29
8.3
0.24 0.78
0.18
50
4.0
0.32
8.0
0.31
50
0.65
6.2
0.65
25
4.0
7.5
0.30
0.36
42
0.54
5.1 0.54
1.5
-
6.0
60
1.5
59.0
2.36
0.26
50
1.5
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
or
the
target
and
seal
-
in
coils
of
the
protective
relay
.
52.0
2.08
0.28
25
1.5
48.0
1.92
0.34
0.5
-
2.0
60
0.5
530.0
470.0
430.0
21.2
0.26
50
0.5
18.8
0.28
25
0.5
17.2
0.34
TAP
>
RANGE
0.5
-
2.0
TAP
RANGE
1.5
-
6.0
AMPS
.
TAP
RANGE
1
4
-
16
AMPS
.
MULTIPLES
OF
MINIMUM
TAP
SETTING
SATURATION
CURVES
AT
VARIOUS
FREQUENCIES
FOR
3
TAP
RANGES
OF
THE TYPE
1
AC
51
A
RELAY
LOWEST
TAP
USED
IN
ALL
CASES
Fig
.
3
.
(
K
-
6306891
-
1
)
Saturation
Curves
for
Lowest
Taps
of
the
Induction
Unit
of
Type
IAC
Relays
with
Inverse
-
time
Characteristics
.
5
Courtesy of NationalSwitchgear.com

GEH
-
1753
Time
Overcurrent
Relays
Type
IAC
A
-
C
8
US
TRIP
BUS
IrJ
1
2
n
¥
3
X
*
lA
-
r
h
LI
n
DEVICE
FUNCTION
NUMBERS
FOR
USE
WITH
ALL
EXTERNAL
DIAGRAMS
61
5
A
zi
=
i
h
50
Instantaneous
Unit
5
-
>
in
M
-
6
51
Overcurrent
,
Relay
,
Type
IAC
Ground
Overcurrent
Relay
,
Type
IAC
Power
Circuit
Breaker
51
N
52
SI
Seal
-
in
Unit
,
with
Target
Trip
Coil
Auxiliary
contact
,
closed
when
breaker
closes
.
Fig
.
4
(
K
-
6375667
-
2
)
Type
IAC
51
A
Relays
used
for
Phase
-
to
-
Phase
and
Ground
Overcurrent
Portection
of
a
3
-
Phase
Circuit
.
External
Connections
of
Three
TC
A
A
-
C
BUS
1
2
3
A
-
C
BUS
1
ZL
2
3
12
ss
1
.
jn
A
-
C
TRIPPING
-
H
1
»
l
«
BXx
‘
UNIT
j
^
L
112
l
0
C
5
l
~
lj
%
lira
.
t
ilrl
10
,
u
-
H
-
X
-
,
t
~
L
,
6
£
1
=
L
11
=
1
TR
|
PP
|
NG
Rf
ACTOR
"
"
"
-
-
1
Fig
.
6
(
K
-
6373669
-
6
)
External
Connections
of
Three
Type
IAC
51
R
Relays
used
for
3
-
Phase
Circuit
Protection
.
Fig
.
3
(
K
6373668
-
1
)
External
Connections
of
Three
Type
IAC
51
A
Relays
used
in
Conjunction
with
Tripping
for
Protection
of
aTThree
-
Phase
Circuit
.
Reactors
6
Courtesy of NationalSwitchgear.com

Time
Overcurrent
Relays
Type
IAC
GEH
-
1753
INSTANTANEOUS
UNIT
INTRODUCTION
mounted
beside
the
adjustable
pole
piece
.
Time
-
current
characteristics
are
shown
in
Fig
.
10
.
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
.
7
)
.
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
.
RATINGS
The
instantaneous
unit
is
designed
to
use
either
of
two
coils
having
pickup
ranges
of
10
to
40
,
and
20
to
80
amperes
respectively
.
The
current
-
closing
rating
of
the
contacts
is
30
amperes
for
voltages
not
exceeding
250
volts
.
BURDENS
Burden
data
on
the
instantaneous
unit
coils
are
given
in
the
following
table
:
APPLICATION
Imp
.
Ohms
Volt
Coil
PF
Freq
.
Amp
.
Amp
The
instantaneous
unit
is
used
on
certain
IAC
relay
models
to
provide
instantaneous
tripping
for
current
exceeding
a
predetermined
value
.
10
-
40
60
5
0.83
0.033
0.032
0.027
0.008
0.008
0.007
0.95
50
5
0.80
0.95
25
0.65
5
0.98
OPERATING
CHARACTERISTICS
20
-
80
60
5
0.21
0.95
The
instantaneous
element
operates
over
a
4
to
1
range
and
has
its
calibration
stamped
on
a
scale
50
5
0.20
0.95
25
5
0.15
0.98
CALIBRATION
«
fi
PLATE
ADJUSTABLE
POLE
PIECE
INSTANTANEOUS
UNIT
OPERATING
COIL
SHORTING
COIL
-
CONTACTS
_
TARGET
STATIONARY
CONTACTS
MAIN
COIL
MOVING
CONTACT
ASSEMBLY
A
-
C
TRIPPING
r
<
>
FM
KAl
>
UNIT
Kk
T
‘
*
*
*
»
»
*
Tll
*
E
A
/
»
«
*
MPCN
.
I
.
.
-
!
N
*
T
*
OCT
(
0
>
.
S
r
Fig
.
7
.
(
8006998
)
Type
IAC
Relay
with
an
Instantaneous
Unit
.
Fig
.
8
.
(
8007060
)
Type
IAC
Relay
with
A
-
C
Tripping
Unit
.
an
7
Courtesy of NationalSwitchgear.com

GEH
-
1753
Time
Overcurrent
Relays
Type
IAC
A
-
C
TRIPPING
UNIT
INTRODUCTION
The
a
-
c
tripping
unit
is
a
Type
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
IAC
relay
.
It
transfers
the
current
from
the
secondary
of
the
current
trans
-
former
into
the
trip
coil
and
removes
the
current
from
the
trip
coil
when
the
breaker
trips
.
The
tripping
unit
is
mounted
on
the
rear
of
the
frame
opposite
the
tapped
operating
coil
of
the
induction
unit
(
see
Fig
.
8
)
.
The
operation
of
this
unit
is
illustrated
in
Fig
.
9
.
The
secondary
current
circulates
through
the
induction
unit
current
coil
and
the
main
coil
of
the
REA
auxiliary
tripping
unit
,
returning
through
the
REA
contacts
to
the
current
transformer
.
Normally
,
most
of
the
flux
generated
by
the
main
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
REA
is
short
-
circuited
and
current
flows
in
this
coil
by
transformer
action
,
causing
a
redistribution
of
flux
which
actuates
the
armature
and
the
REA
contacts
.
The
opening
of
the
REA
contacts
causes
the
secondary
current
to
flow
through
the
trip
coil
which
trips
the
breaker
.
Ti
$
l
BREAKER
TRIP
COIL
CURRENT
TRANS
AC
TRIP
UNIT
NORMALLY
CLOSED
CONTACTS
IOC
T
I
LQC
AC
TRIP
UNIjT
SHORTING
J
COIL
O
v
AC
TRIP
'
UNIT
MAIN
COIL
TOC
Fig
.
9
(
K
-
6154766
-
2
)
Diagram
Illustrating
Operation
of
Type
IAC
Relays
having
an
A
-
C
Tripping
Unit
.
0.030
OPERATING
TIME
RANGE
FOR
ANY
PICKUP
SETTING
0.025
o
Ul
<
r
>
0.020
i
UJ
t
-
0.015
a
.
<
-
>
0.010
Q
-
0.005
0
7
fa
y
io
3
5
6
0
4
MULTIPLES
OF
PICK
-
UP
(
6306872
[
5
]
)
Time
-
current
Characteristics
o f
Original
Instantaneous
Unit
Fig
.
10
8
Courtesy of NationalSwitchgear.com