GE IAC53A User manual

INSTRUCTIONS
GEH
-
1788
L
TIME
OVERCURRENT
RELAYS
TYPES
IAC
53
A
IAC
53
B
IAC
53
C
IAC
53
R
IAC
54
A
IAC
54
B
GENERAL
^
ELECTRIC
Courtesy of store.ips.us

GEH
-
1788
Tvne
IAC
Time
Overcurrent
Relay
TOP
PIVOT
TAP
PLUG
SEAL
-
IN
UNIT
HOLDING
COIL
SEAL
-
IN
TARGET
SEAL
-
IN
—
-
UNIT
STATIONARY
CONTACT
,
LEFT
SEAL
-
IN
UNIT
STATIONARY
CONTACT
,
RIGHT
TAP
BLOCK
—
TIME
DIAL
DISK
SHAFT
MAIN
MOVING
CONTACT
MAIN
STATIONARY
BRUSH
AND
CONTACT
ASSEMBLY
1
r
MAGNET
DISK
SEAL
-
IN
MOVING
CONTACT
ASSEMBLY
Lf
>
£
3
04
04
O
00
Ol
Li
_
Fig
.
I
The
Induction
Unit
for
Type
IAC
Relays
(
Front
View
)
00
04
in
04
04
-
CRADLE
o
oo
04
cn
u
_
DISK
AND
SHAFT
COIL
AND
TAP
BLOCK
ASSEMBLY
ID
ao
04
LT
)
CO
o
oo
k
.
<
D
>
O
LOWER
JEWEL
SCREW
.
.
/
o
Fig
.
2
The
Induction
Unit
for
Type
IAC
Relays
(
Rear
View
)
2
Courtesy of store.ips.us

TIME
OVERCURRENT
RELAYS
TYPE
IAC
INTRODUCTION
Contact
Circuits
Instan
.
A
-
C
Trip
Indue
.
Outline
&
P
.
D
.
Int
.
Conn
.
Type
Unit
Unit
Unit
IAC
53
A
(
“
)
A
IAC
53
B
(
-
)
A
LAC
53
C
(
-
)
A
iAC
53
R
(
-
)
A
IAC
54
A
(
-
)
A
IAC
54
B
(
-
)
A
One
One
One
One
Two
Two
No
Fig
.
12
Fig
.
13
Fig
.
14
Fig
.
15
Fig
.
16
Fig
.
17
No
One
One
On
3
One
One
One
Fig
.
20
Fig
.
20
Fie
.
20
Fig
.
20
Fig
.
20
Fig
.
20
Yes
No
No
Yes
Yes
Yes
No
No
Yes
No
The
Types
IAC
53
and
IAC
54
relays
are
time
overcurrent
relays
with
a
very
-
inverse
time
char
-
acteristic
.
overcurrent
on
single
-
phaseandpoly
-
phasecircuits
.
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
.
mits
instantaneous
tripping
for
exteremely
high
cur
-
rents
,
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
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
and
panel
drilling
diagrams
.
They
are
employed
to
protect
against
These
relays
consist
of
an
induction
unit
or
an
induction
unit
with
an
instantaneous
unit
which
per
-
INDUCTION
UNIT
APPLICATION
INTRODUCTION
The
induction
unit
is
the
main
unit
in
all
Type
IAC
relays
,
supplying
the
very
inverse
time
delay
characteristics
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
Type
IAC
relays
.
Figs
.
1
and
2
show
the
induction
unit
mounted
in
the
cradle
.
These
units
are
of
the
induc
-
tion
-
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
-
cur
-
rent
characteristics
are
shown
in
Fig
.
3
.
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
.
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
.
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
Should
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
Courtesy of store.ips.us

GEH
-
1788
Type
IAC
Time
Overcurrent
Relay
ii
i
i
mil
I
SI
!
!
!
!!
*
I
i
•
*
»
*
8
^
S
.
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7
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»
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0
1
I
4
B
I
7
I
lit
St
44
II
M
78
N
MS
1044
16
M
Mi
•
00
M
4
MO
704
Mfl
EXTENDED
P
/
NGE
(
8
C
0
EERlEC
)
tit
•
04
ADJUSTMENTS
441
4
M
RATINGS
INST
.
UNIT
TIME
UNIT
TAPS
I
N
ST
UNIT
TIME
UNIT
tft
Mi
CONTINUOUSLY
ADJUSTABLE
G
•
5
,
0
6
,
0
-
7
^
0
8
,
1
-
0
;
1
*
2
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5
,
2
0
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,
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-
5
^
3
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j
2
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6
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7
-
Oj
8.0
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10
,
12
2
-
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-
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,
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.
O
3
4
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OjS
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-
Oj
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,
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6
0.5
-
4
-
0
2
-
16
10
-
80
20
-
160
Q
.
5
-
4.0
I
.
5
-
12.0
stt
100
2
-
16
104
m
*
mm
100
•
4
M
W
M
74
70
M
M
M
90
M
20
10
IB
A
A
1
7
\
VUu
\
\
MV
A
•
d
I
•
v
.
s
\
O
4
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YC
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8
.
2
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.
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s
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s
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x
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s
V
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W
•
s
\
V
\
N
10
v
t
1
\
V
9
.
0
\
.
0
8
\
V
,
N
7
s
in
-
.
4
\
\
6
9
\
B
C
s
x
x
5
v
.
4
4
\
N
V
®
s
CO
.
s
3
s
\
V
o
X
\
2
o
.
2
\
S
N
®
\
E
x
-
N
.
H
.
1
.
1
.
04
.
0
«
k
M
.
07
JS
M
jn
n
JS
JI
I
I
iMillf
J
*
J
.
4
.
7
.
0
J
1
a
4
1
min
St
44
44
44
70
BOM
|
I
III
I
Kill
MULTIPLES
OF
RELAY
TAP
SETTING
M
Figure
3
(
0888
B
0270
[
3
]
)
Time
-
Current
Curves
for
Type
IAC
Relays
with
Very
-
Inverse
-
Time
Characteristics
4
Courtesy of store.ips.us

Type
LA
.
C
Time
Overcurrent
Relay
GEH
-
1788
CM
LO
CALIBRATION
PLATE
ADJUSTABLE
POLE
PIECE
CM
I
3
a
ao
CONTACTS
INSTANTANEOUS
W
UNIT
OPERATING
COIL
-
TARGET
STATIONARY
CONTACTS
MOVING
CONTACT
ASSEMBLY
SHORTING
.
COIL
u
.
MAIN
COIL
A
-
C
TRIPPING
”
UNIT
to
CM
to
CM
CM
o
oo
to
Ol
li
.
Type
I
AC
Relay
with
an
Instantaneous
Unit
(
Front
View
)
Fi
g
.
Fig
.
4
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
:
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
.
Amperes
,
a
-
c
or
d
-
c
Volt
Imp
.
Ohms
Coil
PF
Function
Amps
Freq
.
Tap
Amps
Amps
2
-
Amp
Tap
0.2
Amp
Tap
5
Tripping
Duty
Carry
Continuously
Operating
Range
Resistance
Impedance
at
60
cy
30
0.08
0.50
5
60
4
2.0
4
-
16
0.3
3
0.07
5
0.50
50
1.7
4
0.2
-
2
2
-
30
0.05
0.61
5
1.3
25
4
7
0.13
0.58
0.42
1.5
-
6
60
1.5
5
14.5
52
0.53
0.48
0.42
50
1.5
5
12.0
0.36
0.55
25
1.5
5
9.0
4.20
0.5
*
2
0.35
0.5
60
5
105.0
3.45
0.34
0.5
50
5
86.0
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
.
3.28
0.55
0.5
5
25
82.0
*
0.38
122
3050
2546
5
0.1
60
0.1
-
0.4
0.36
102
5
0.1
50
INSTANTANEOUS
UNIT
INTRODUCTION
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
.
5
Courtesy of store.ips.us

GEH
-
1788
Type
IAC
Time
Overcurrent
Relay
26
24
22
TAP
RANGE
0.5
-
2.0
AMPS
.
20
16
DQ
'
V
16
25
/
-
U
V
14
0
L
T
12
CM
o
TAP
60
AJ
o
O
RANGE
1.5
-
6.0
AMPS
.
-
5
0
'
v
*
<
o
25
^
TAP
cr
>
60
^
NJ
'
.
RANGE
4
-
16
AMPS
.
ii
.
50
oj
2
5
MULTIPLES
OF
MINIMUM
PlCK
-
UP
CURRENT
SATURATION
CURVES
FOR
LOWEST
TAPS
OF
INDUCTION
UNITS
ON
VERY
INVERSE
TYPE
IAC
RELAYS
Saturation
Curves
for
Lowest
Taps
of
tne
Induction
Unit
of
Type
IAC
Relays
with
Very
-
Inverse
-
Time
Characteristics
6
Courtesy of store.ips.us

Type
1
AC
Time
Overcurrent
Relay
(
JEH
-
1788
0.030
1
T
OPERATING
TIME
RANGE
FOR
ANY
PICKUP
SETTING
T
0.025
o
Ul
0.020
1
UJ
*
-
0.015
a
.
e
0.010
a
.
0.005
0
0
2
3
4
5
6
7
8
9
10
MULTIPLES
OF
PICK
-
UP
Fig
.
7
A
(
K
-
6306872
[
3
]
)
Time
-
Current
Characteristics
for
Original
Instantaneous
Unit
111
SEISMIC
RATED
INSTANTANEOUS
UNIT
OPERATING
TIME
T
1
t
.
025
T
T
1
,
1
1
—
1
1
t
•
.
020
1
a
L
v
-
i
8
1
.
©
l
&
\
2
1
OPERATING
TIME
RANGE
FOR
ANY
PICKUP
SETTING
a
.
§
.
010
a
.
\
.
005
9
10
4
3
1.5
2
MULTIPLES
OF
PICKUP
Fig
.
7
B
(
0208
A
869
5
-
1
)
Time
-
Current
Characteristics
for
the
,
?
Hi
-
G
”
Unit
7
Courtesy of store.ips.us

GEH
-
1788
Type
IAC
Time
Overcurrent
Relay
APPLICATION
RATINGS
The
instantaneous
unit
is
used
on
certain
Type
IAC
relay
models
to
provide
instantaneous
tripping
for
current
exceeding
a
predetermined
value
.
The
instantaneous
unit
is
designed
to
use
the
coils
listed
below
;
Coil
Amp
Volt
-
Amp
Freq
Imp
.
Ohms
P
.
F
.
5
0.5
-
2
60
360
14.4
0.74
OPERATING
CHARACTERISTICS
5
3.6
1
-
4
60
0.77
90
5
2
-
8
60
22.5
0.83
0.90
5
25
0.32
0.83
8.0
5
5.63
4
-
16
60
0.225
0.191
0.157
0.095
0.87
*
The
instantaneous
unit
operates
over
a
four
-
calibration
stamped
on
5
4.77
0.87
50
and
has
its
to
-
one
range
a
scale
mounted
beside
the
adjustable
pole
piece
.
Time
-
current
5
40
3.93
0.88
5
2.37
25
0.88
characteristics
are
shown
in
Fig
.
7
A
for
the
instantaneous
unit
used
before
1977
.
5
7
-
28
60
1.68
0.067
0.88
In
1977
make
it
have
a
higher
seismic
rating
,
instantaneous
unit
can
be
identified
by
the
mark
-
ing
"
Hi
-
G
"
moulded
into
the
front
moulding
just
above
the
target
windows
,
characteristic
for
the
"
Hi
-
G
"
Fig
.
7
B
.
the
instantaneous
unit
was
modified
to
The
new
5
60
0.83
0.033
0.032
0.027
10
-
40
0.95
5
0.80
50
0.95
5
25
0.68
0.98
time
-
current
The
unit
is
shown
in
5
20
-
80
60
0.20
0.008
0.008
0.007
0.95
5
0.20
50
0.95
LJ
.
25
0.18
0.98
A
-
C
TRIPPING
UNIT
circulates
through
the
induction
unit
cur
rent
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
.
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
Type
IAC
relay
.
It
transfers
the
current
from
the
secondary
of
the
current
transformer
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
in
-
duction
unit
(
see
Fig
.
5
)
.
The
operation
of
this
unit
is
illustrated
in
Fig
.
11
.
The
secondary
current
8
*
Indicates
revision
Courtesy of store.ips.us

Type
IAC
Time
Overcurrent
Relay
GEH
-
1788
A
—
C BuS
.
TRIP
B L
$
1
2
n
51
N
Device Function Numbers
for
Use
with
ALL
External
Diagrams
Instantaneous
Unit
Overcurrent
Relay
,
Type
IAC
Ground
Overcurrent
Relay
,
Type
IAC
Power
Circuit
Breaker
Seal
-
in
Unit
,
with
Target
Trip
Coil
Auxiliary
Contact
,
closed
when
breaker closes
3
SI
51
-
51
-
1
Ji
rr
SIN
T
i
i
50
J
l
J
51
2
52
51
N
Ilk
r
TC
52
SI
TC
A
l
5
j
51
-
3
51
-
1
0
'
"
.
*
1
H l
"
5
,
_
JLT
Figure
8
(
K
-
6375667
[
2
]
)
External
Connections
of
Three
Type
IAC
53
A
Relays
Used
for
Phase
-
to
-
Phase
and
Ground
Overcurrent
Protection
of
a
3
-
Phase
Circuit
A
-
C
BIS
1
2
A
-
C
BUS
1
3
2
3
52
.
52
1
TOC
8
A
-
C
TRIPPING
5
Toe
51
=
3
UNIT
11
=
1
Hll
*
1
IOC
X
1
H
1
6
hi
F
liriL
TRIPPING
|
RT
ACT
0
R
“
*
,
1
51
-
2
51
-
1
It
i
i f
i
t
10
9
2
^
f
2
-
y
M
6
Figure
9
.
(
K
6375668
-
1
)
External
Connections
of
Three
Type
IAC
53
A
Relays
used
in
Conjunction
with
Tripping
Reactors
for
Protection
of
a
3
-
Phase
Circuit
Figure
10
.
(
K
-
6375669
-
6
)
External
Connections
of
Three
Type
IAC
53
R
Relays
Used
For
3
-
Phase
Circuit
Protection
9
Courtesy of store.ips.us

GEH
-
1788
Type
IAC
Time
Overcurrent
Relay
APPLICATION
The
a
-
c
tripping
unit
is
used
in
Type
IAC
relays
where
a
reliable
direct
-
current
tripping
source
is
not
available
and
it
is
necessary
to
trip
the
breaker
from
the
current
-
transformer
secondary
.
T
«
5
S
I
BREAKER
TRIP
COIL
RATINGS
The
a
-
c
tripping
unit
has
a
continuous
rating
of
five
amperes
but
will
operate
on
a
minimum
current
of
3.5
amperes
.
It
should
be
used
with
three
-
ampere
trip
coils
.
The
contacts
of
these
units
will
transfer
current
-
transformer
secondary
current
up
to
100
amperes
.
For
applications
where
the
sec
-
ondary
current
exceeds
100
amperes
,
the
Type
REA
11
B
relay
,
which
has
contacts
rated
200
am
-
peres
,
can
be
used
in
conjunction
with
Type
IAC
overcurrent
relays
,
mounted
inside
the
Type
IAC
case
.
AC
TRIP
UNIT
NORMALLY
CLOSED
CONTACT
S
CURRENT
TRANS
IOC
:
:
T
0
C
LQC
AC
TRIP
UNIT
SHORTING
COIL
~
T
T
The
Type
REA
1
IB
is
not
CVJ
VO
BURDENS
vo
ID
Burdens
of
the
Type
REA
unit
are
given
in
the
following
table
:
vO
o
AC
TRIP
UNI
I
MAIN
COIL
Volt
-
Amperes
Impedance
in
Ohms
PF
IQ
£
CD
Frequency
Amps
60
0.80
12.2
5
0.49
50
5
0.33
0.80
8.3
Diagram
Illustrating
Operation
of
Type
IAC
Relays
having
an
A
-
C
Tripping
Unit
*
Fi
g
.
II
0.62
25
5
0.23
5.8
RECEIVING
,
HANDLING
AND
STORAGE
ing
the
relay
in
order
that
none
of
the
parts
are
injured
or
the
adjustments
disturbed
.
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
Apparatus
Sales
Office
.
If
the
relays
are
not
to
be
installed
immed
-
iately
,
they
should
be
stored
in
their
original
car
-
tons
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
.
Reasonable
care
should
be
exercised
in
unpack
-
INSTALLATION
relay
types
are
shown
in
Figs
.
12
to
17
inclusive
.
Typical
wiring
diagrams
are
given
in
Figs
.
8
to
10
inclusive
.
LOCATION
The
location
should
be
clean
and
dry
,
free
from
dust
and
excessive
vibration
,
and
well
lighted
to
facilitate
inspection
and
testing
.
One
of
the
mounting
studs
or
screws
should
be
permanently
grounded
by
a
conductor
not
less
than
No
.
12
B
&
S
gage
copper
wire
or
its
equivalent
.
MOUNTING
INSPECTION
'
n
The
relay
should
be
mounted
on
a
vertical
The
outline
and
panel
diagram
is
shown
surface
.
At
the
time
of
installation
,
the
relay
should
be
inspected
for
tarnished
contacts
,
loose
screws
,
or
other
imperfections
.
If
any
trouble
is
found
,
it
should
be
corrected
in
the
manner
described
under
MAINTENANCE
.
in
Fig
.
20
.
CONNECTIONS
The
internal
connection
diagrams
for
the
various
10
*
Indicates
Revision
Courtesy of store.ips.us

Type
IAC
Time
Overcurrent
Relay
GEH
-
1788
O
co
in
cn
o
INDUCTiON
UNIT
INSTANT
UNIT
CM
<
o
SEAL
-
IN
UNIT
.
i
H
CM
:
n
_
*
a
\
UNIT
SEAL
-
IN
UNIT
Li
-
H
T
T
f
V
•
V
V
V
•
v
*
v
•
\
/
V
\
y
“
V
I
v
I
V
I
"
V
t
vj
3
5
5
1
a
6
0
r
\
©
2
6
2
6
*
-
$
HORT
FINGER
%
£
>
*
SHORT
FINGER
\
D
cn
O
CM
vO
I
u
CO
Fig
.
12
Internal
Connections
for
Type
IAC
53
A
Relay
(
Front
View
)
Fig
.
13
Internal
Connections
for
Type
IAC
53
B
Relay
(
Front
View
)
Ol
U
-
INDUCT
I
UNIT
£
A
-
C
TRIP
UNIT
INDUCTION
UNIT
r
SEAL
-
IN
UNIT
s
SEAL
-
IN
UNIT
X
11
A
-
C
TRIP
UNIT
\
y
SEAL
-
IN
UNI
T
A
-
C
TRI
^
UNIT
s
T
N
U
s
S
N
INSTANT
UN
.
1
T
INDUCTION
UNIT
T
I
T
A
T
N
XL
T
T
V
V
V
oo
V
-
—
V
V V
>
t
y
y
y
i
3
v
V
V
V
I
9
^
r
cn
CM
O
O
O
2
6
CM
7
5
3
1
o
o
0
10
6
8
2
4
Fig
.
m
(
K
-
6209660
-
7
)
Type
IAC
53
C
Relay
(
Front
View
)
Internal
Connections
For
*
Fi
g
.
15
Internal
Connections for
Type
IAC
53
R
Relay
(
Front
View
)
cn
ti
-
ll
*
Indicates
Revision
Courtesy of store.ips.us

GEH
-
17
MB
Type
IAC
Time
Overcurrent
Heiay
INDUCTION
x
UNIT
v
iu
JNI
s
i
.
T T
sT
”
I
NDUCT
ICN
ii
/
i
\
INDUCTiON
UN
T
SEAL
-
IN
UNIT
INSTANT
.
UN
I
T
SIT
T
ST
_
L
~
n
4
k
.
rn
to
INDUCT
ION
UNIT
SEAL
-
I
N
UK
I
T
A
cn
r
\
j
o
<
J
\
Ul
INSTANT
.
UN
IT
V
V
S
I
3
00
5
1
T
*
r
3
5
y
*
y
.
i
«
v
.
O
V
"
V
I
1
2
6
9
SHORT
FINGER
o
2
6
10
n
to
*
-
SHORT
FINGER
cn
i
cr
>
P
\
J
Internal
‘
Connections
for
Type
IAC
5
M
-
A
Internal
Connections
for
Type
IAC
54
B
Fig
.
17
o
Fig
.
16
v
£
>
o
>
ro
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
Every
circuit
in
the
drawout
case
has
an
the
main
brushes
do
.
This
will
prevent
CT
sec
-
auxiliary
brush
.
It
is
especially
important
on
ondary
circuits
from
being
opened
.
CAUTION
:
CONNECTING
PLUG
MAIN
BRUSH
CONNECTING
BLOCK
~
n
IQ
TERMINAL
BLOCK
SHORTING
BAR
NOTE
AFTER
ENGAGING
AUXILIARY
BRUSH
,
CONNECTING
PLUG
TRAVELS
'
A
INCH
BEFORE
ENGAGING
THE
MAIN
BRUSH
ON
THE
TERMINAL
BLOCK
AUXILIARY
BRUSH
oo
00
o
CJl
o
CO
CO
Fig
.
18
Cutaway
of
Drawout
Case
Showing
Position
of
Auxiliary
Brush
12
Courtesy of store.ips.us

Type
IAC
Time
Overcurrent
Relay
GEH
-
1788
ADJUSTMENTS
TARGET
AND
SEAL
-
IN
UNIT
contacts
and
therefore
this
setting
gives
the
max
-
imum
time
setting
.
The
primary
adjustment
for
the
time
of
oper
-
ation
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
main
shaft
of
the
unit
decreases
the
time
,
while
moving
it
away
increases
the
time
.
If
selective
action
of
two
or
more
relays
is
required
,
determine
the
maximum
possible
short
-
circuit
current
of
the
line
and
then
choose
a
time
value
for
each
relay
that
differs
sufficiently
to
insure
the
proper
sequence
in
the
operation
of
the
several
circuit
breakers
.
made
for
the
time
involved
in
opening
each
breaker
after
the
relay
contacts
close
.
For
this
reason
,
unless
the
circuit
time
of
operation
is
known
with
accuracy
,
there
should
be
a
dfifference
of
about
0.5
second
(
at
the
maximum
current
)
between
relays
whose
operation
is
to
be
selective
.
For
trip
coils
operating
on
currents
ranging
from
0.2
to
2.0
amperes
at
the
minimum
control
voltage
,
set
the
target
and
seal
-
in
tap
screw
in
the
0.2
-
ampere
tap
.
For
trip
coils
operating
on
currents
ranging
from
2
to
30
amperes
at
the
minimum
control
voltage
place
the
tap
screw
in
the
2
-
ampere
tap
.
The
tap
screw
is
the
screw
holding
the
right
-
hand
stationary
contact
of
the
seal
-
in
unit
.
To
change
the
tap
setting
,
first
remove
the
connecting
plug
.
stationary
contact
and
place
it
in
the
desired
tap
.
Next
,
remove
the
screw
from
the
other
tap
and
place
it
in
the
left
-
hand
contact
.
This
procedure
is
necessary
to
prevent
the
right
-
hand
stationary
contact
from
getting
out
of
adjustment
.
Screws
should
not
be
in
both
taps
at
the
same
time
.
Then
,
take
a
screw
from
the
left
-
hand
Allowance
must
be
INDUCTION
UNIT
EXAMPLE
OF
SETTING
CURRENT
SETTING
The
time
and
current
settings
of
the
over
-
current
unit
can
be
made
easily
and
quickly
.
Each
time
value
shown
in
Fig
.
3
indicates
the
time
required
for
the
contacts
to
close
with
a
particular
time
-
dial
setting
when
the
current
is
a
prescribed
number
of
times
the
current
-
tap
setting
.
In
order
to
secure
any
of
the
particular
time
-
current
settings
shown
in
Fig
.
3
,
insert
the
removable
plug
in
the
proper
tap
receptacle
and
adjust
the
time
-
dial
to
the
proper
position
.
The
following
example
il
-
lustrates
the
procedure
in
making
a
relay
setting
:
The
current
at
which
the
contacts
operate
may
be
changed
by
changing
the
position
of
the
tap
plug
in
the
tap
block
at
the
top
of
the
relay
.
Screw
the
tap
plug
firmly
into
the
tap
marked
for
the
desired
current
(
below
which
the
unit
is
not
to
operate
)
.
When
changing
the
current
setting
of
the
unit
,
remove
the
connecting
plug
to
short
-
circuit
the
current
-
transformer
secondary
circuit
,
screw
the
tap
plug
into
tap
marked
for
the
desired
current
and
then
replace
the
connecting
plug
.
Next
,
Assume
a
Type
IAC
relay
is
used
in
a
circuit
where
the
circuit
breaker
should
trip
on
a
sustained
current
of
approximately
450
amperes
;
also
,
the
breaker
should
trip
in
1.0
second
on
a
short
-
circuit
current
of
3750
amperes
.
Assume
further
that
current
transformers
of
60
/
1
ratio
are
used
.
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
tool
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
be
-
tween
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
per
cent
of
the
tap
plug
setting
.
The
unit
resets
at
90
per
cent
of
the
minimum
closing
value
.
The
current
tap
setting
is
found
by
dividing
the
minimum
primary
tripping
current
by
the
current
transformer
ratio
.
In
this
case
,
450
divided
by
60
equals
7.5
amperes
.
Since
there
is
no
7.5
ampere
tap
,
the
8
-
ampere
tap
is
used
.
To
find
the
proper
time
-
dial
setting
to
give
1.0
-
second
time
delay
at
3750
amperes
,
divide
3750
by
the
transformer
ratio
.
This
gives
62.5
amperes
secondary
current
which
is
7.8
times
the
8
-
ampere
petting
.
By
re
-
ferring
to
the
time
current
curves
^
(
Fig
.
3
)
,
it
will
be
seen
that
7.8
times
the
minimum
operating
current
gives
1.0
-
second
time
delay
when
the
relay
is
set
on
the
No
.
6
time
-
dial
setting
.
TIME
SETTING
The
setting
of
the
time
dial
determines
the
length
of
time
the
unit
requires
to
close
its
con
-
tacts
when
the
current
reaches
the
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
The
above
results
should
be
checked
by
means
of
an
accurate
timing
device
.
Slight
readjustment
of
the
dial
can
be
made
until
the
desired
time
is
obtained
.
13
Courtesy of store.ips.us

GEH
-
1788
Type
IAC
Time
Overcurrent
Relay
Aid
in
making
the
proper
selection
of
relay
settings
may
be
obtained
on
application
to
the
near
-
est
Sales
Office
of
the
General
Electric
Company
.
TO
TIMER
"
STOP
"
TO
INDICATING
LIGHT
WUEN
CHECKING
PICKUP
OF
MAIN
UNIT
INSTANTANEOUS
UNIT
—
=
*
n
Select
the
current
above
which
is
desired
to
have
the
instantaneous
unit
operate
and
set
the
adjustable
pole
piece
so
that
the
top
of
its
hexagon
head
is
even
with
the
desired
calibration
on
the
scale
.
To
raise
or
lower
the
pole
piece
,
loosen
the
locknut
and
turn
it
up
or
down
and
then
tighten
in
position
.
M
*
TO
INDICATING
LIGHT
AMEN
CHECKING
PICKUP
OF
INSTANTANEOUS
UNIT
09
+
66606
1 2
3
4
5
7
S
cr
>
c
*
u
>
OOOOO
6
7
8
9
1
C
VO
-
«
4
The
contacts
should
be
adjusted
to
make
at
about
the
same
time
and
to
have
approximately
1
/
8
inch
wipe
.
This
adjustment
can
be
made
by
loosening
the
screws
holding
the
stationary
contacts
and
moving
the
contacts
up
or
down
as
required
.
XLA
13
TEST
PLUG
A
VARIABLE
RESISTOR
Vj
\
\
A
-
C
TRIPPING
UNIT
TO
TIMER
"
START
"
The
a
-
c
tripping
unit
should
not
require
any
attention
other
than
occasional
cleaning
of
the
con
-
tacts
.
However
,
if
the
adjustment
should
be
lost
,
it
may
be
restored
as
follows
:
TO
ACCURATELY
REPRODUCE
RELAY
CHARACTERISTICS
ALL
TESTS
SHOULD
BE
MADE
WITH
RELAY
IN
CASE
.
/
/
J
MIN
.
RECOMMENDED
VOLTS
,
120
AT
RATED
FREQUENCY
CONTACT
ADJUSTMENT
With
the
unit
de
-
energized
,
the
movable
contact
should
lie
against
the
stationary
contact
with
enough
tension
to
always
insure
a
good
closed
circuit
.
The
movable
contact
brush
should
be
free
of
anv
kinks
.
Also
this
contact
brush
should
not
touch
th
pound
bushing
supported
from
the
top
of
the
arma
-
ture
.
The
brass
backing
strip
should
be
adjusted
to
allow
a
1
/
16
-
inch
contact
gap
with
the
contacts
open
.
adjusted
to
allow
the
back
of
the
movable
contact
to
just
touch
the
brass
backing
strip
when
the
armature
operates
to
open
the
contacts
.
The
outer
edge
of
the
compound
bushing
should
be
approximate
-
ly
1
/
32
inch
from
the
inner
edge
of
the
stationary
-
contact
supporting
post
.
Fig
.
19
Test
Connections
for
Testing
Pickup
&
Time
Curve
of
IAC
Relays
e
corn
-
spaced
clear
of
both
armature
and
the
vertical
tip
of
the
bracket
.
With
this
setting
,
the
armature
should
be
flush
against
the
pole
face
of
both
cores
,
and
should
put
enough
pressure
on
the
armature
to
always
return
it
flush
against
the
pole
face
of
the
lower
core
after
each
operation
of
the
unit
,
alignment
is
important
as
a
slight
gap
between
armature
and
pole
face
of
the
lower
core
after
the
unit
operates
may
cause
contacts
to
open
momen
-
tarily
,
dropping
the
relay
target
when
the
circuit
breaker
is
reclosed
.
Under
these
conditions
,
the
momentary
opening
of
the
contacts
is
due
to
the
shock
of
the
armature
being
pulled
in
against
the
pole
face
when
the
lower
coil
is
energized
.
Ex
-
cessive
pressure
on
the
armature
,
caused
by
the
bracket
being
pushed
in
too
far
,
will
result
in
too
high
a
pickup
or
chattering
of
the
movable
contact
during
operation
of
the
unit
.
Tighten
the
bracket
screws
securely
after
the
proper
adjustment
has
been
obtained
.
The
compound
bushing
support
should
be
This
ARMATURE
ADJUSTMENT
Loosen
the
two
screws
which
hold
the
armature
-
assembly
bracket
to
the
bottom
of
the
frame
.
Slide
the
bracket
in
or
out
,
whichever
is
necessary
,
until
the
armature
just
touches
the
pole
face
of
the
upper
core
.
In
this
position
,
the
armature
should
be
about
1
/
32
inch
from
the
pole
face
of
the
lower
core
.
Next
,
slide
the
bracket
in
until
the
armature
leaf
spring
assumes
a
vertical
position
and
is
OPERATION
Before
the
relay
is
put
into
service
it
should
be
given
a
check
to
determine
that
factory
adjust
-
ments
have
not
been
disturbed
.
The
time
dial
will
be
set
at
zero
before
the
relay
leaves
the
factory
.
It
is
necessary
to
change
this
setting
in
order
to
open
the
relay
contacts
.
The
pick
-
up
current
should
be
checked
on
one
or
more
of
the
taps
and
the
time
should
be
checked
for
one
or
more
dial
settings
.
Recommended
test
connections
for
the
above
test
are
shown
in
Fig
.
19
.
14
Courtesy of store.ips.us

Type
IAC
Time
Overcurrent
Relay
GEH
-
1788
MAINTENANCE
DISK
AND
BEARINGS
and
thoroughly
.
The
flexibility
of
the
tool
insures
the
cleaning
of
the
actual
points
of
contact
.
Fine
silver
contacts
should
not
be
cleaned
with
knives
,
files
,
or
abrasive
paper
or
cloth
.
Knives
or
files
may
leave
scratches
which
increase
arcing
and
deterioration
of
the
contacts
.
Abrasive
paper
or
cloth
may
leave
minute
particles
of
insulating
abrasive
material
in
the
contacts
and
thus
prevent
closing
.
The
burnishing
tool
described
is
included
in
the
standard
relay
tool
kit
obtainable
from
the
factory
.
The
lower
jewel
may
be
tested
for
cracks
by
exploring
its
surface
with
the
point
of
a
fine
needle
.
The
jewel
should
be
turned
up
until
the
disk
is
centered
in
the
air
gaps
,
after
which
it
should
be
locked
in
this
position
by
the
set
screw
provided
for
this
purpose
.
CONTACT
CLEANING
For
cleaning
fine
silver
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
corroded
material
will
be
removed
rapidly
PERIODIC
TESTING
It
is
recommended
that
pickup
of
all
units
be
checked
at
least
once
every
six
months
.
ACCEPTANCE
TESTS
B
.
INSTANTANEOUS
UNIT
ELECTRICAL
Pickup
A
.
MAIN
UNIT
With
gradually
applied
current
the
unit
should
pickup
at
±
10
%
of
the
minimum
calibration
.
There
should
be
no
more
than
±
5
%
variation
on
repeated
pickup
checks
.
Be
sure
the
target
has
been
reset
after
each
test
.
Pickup
Set
the
relay
at
the
0.5
time
dial
position
and
minimum
tap
.
Using
the
test
connections
of
Figure
19
the
main
unit
should
close
its
contacts
within
±
5
%
of
tap
value
current
.
Time
Test
C
.
TARGET
SEAL
IN
UNIT
Pickup
Set
the
relay
at
the
5.0
time
dial
position
and
minimum
tap
.
Using
the
test
connections
of
Figure
19
,
and
applying
5
times
pickup
current
,
the
relay
should
operate
at
1.31
seconds
±
7
%
.
With
2
times
pickup
current
applied
the
operating
time
should
be
7.21
seconds
±
7
%
.
With
10
times
pickup
current
applied
the
operating
time
should
be
0.72
seconds
±
7
%
.
The
unit
should
pickup
between
75
and
100
%
of
tap
value
with
the
main
unit
contacts
closed
.
Dropout
Open
the
main
unit
contacts
,
the
seal
in
unit
should
remain
picked
up
.
Reduce
the
current
to
25
%
of
tap
value
;
the
unit
should
drop
out
.
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
Com
-
pany
,
specify
the
quantity
required
and
describing
the
parts
by
catalogue
numbers
as
shown
in
Renewal
Parts
Bulletin
No
.
GEF
-
3883
.
15
Courtesy of store.ips.us

GEH
-
1788
Type
IAC
Time
Overcurrent
Relay
PANEL
LOCATION
SEMI
-
FLUSH
MTG
.
SURFACE
(
2
)
5
/
16
-
18
STUDS
FDR
SURFACE
MTG
.
6.625
168
MM
MTG
1
"
C
8.375
212
MM
9
.
125
232
MM
(
4
)
10
-
32
X
3
/
8
MTG
.
SCREWS
STUD
NUMBERING
1
0
-
32
STUDS
9
7
5
3
1
O
O
O
O
O
oo
o
o
o
10
8
6
-
v
2
GLASS
t
1
.
125
29
MM
75
BACK
VIEW
19
MM
1
/
4
DRILL
4
HOLES
3.0
6.187
157
MM
76
MM
6
MM
5
/
8
DRILL
2
HOLES
15
MM
J
!
li
CUTOUT
MAY
REPLACE
DRILLED
HOLES
{
<
>
o
4.406
1
12
MM
!
1
.
156
29
MM
2.187
56
MM
r
3
,
0
l
-
1
CUTtlUT
%
f
76
MM
?
f
I
4.375
11
1
MM
8.812
223
MM
i
3.9061
99
MM
I
.
.
4.281
1
08
MM
1
1
1
,
468
37
MM
<
>
O
i
3
!
I
I
718
2.5
C
„
2
843
72
MM
1
8
MM
6
MM
1
-
.
218
^
^
5
MM
PANEL
-
^
.
500
12
MM
(
TYPICAL
)
218
5.25
5
MM
133
MM
5
,
687
144
MM
3
/
4
DRILL
10
HDLES
19
MM
PANEL
DRILLING
FDR
SEMI
-
FLUSH
MOUNTING
FRONT
VIEW
PANEL
DRILLING
FOR
SURFACE
MOUNTING
FRONT
VIEW
in
5
/
16
-
18
STUD
3
,
0
76
MM
VIEW
SHOWING
ASSEMBLY
OF
HARDWARE
FOR
SURFACE
MTG
.
ON
STEEL
PANELS
TYPICAL
DIM
.
INCHES
MM
Fig
.
20
(
K
-
6209271
[
8
J
)
Outline
and
Panel
Drilling
Dimensions
for
Relay
Types
IAC
Relays
(
11
/
91
)
(
200
)
GENERAL
ELECTRIC
CO
.
,
POWER
SYSTEMS
MANAGEMENT
BUSINESS
DEPT
.
,
MALVERN
,
PA
.
19355
Courtesy of store.ips.us