GE AK-50 Series Technical specifications

GEK
-
7303
C
*
A
Lowvoltage
Power
Circuit
Breakers
Maintenance
Instructions
'
Supersedes
GEH
-
1798
A
GEH
-
1799
GEH
-
1823
G
El
-
5021
OA
GEI
-
50211
GEI
-
50212
A
GEI
-
57077
G
El
-
74600
Types
AK
-
50
/
75
/
100
,
AKT
-
50
,
AKU
-
50
,
and
AKF
-
2
C
/
2
D
/
2
E
NOTE
:
To
be
used
in
conjunction
with
GEl
-
86135
which
covers
Types
AK
-
75
/
100
breakers
with
ECS
and
SST
trip
devices
.
ELECTRIC
GENERAL
Courtesy of NationalSwitchgear.com

CONTENTS
3
INTRODUCTION
3
OPERATION
MANUAL
CLOSING
.
.
.
MANUAL
MAINTENANCE
CLOSING
OF
ELECTRICAL
BREAKERS
ELECTRICAL
CLOSING
.
QUICK
CLOSE
FOR
ELECTRICAL
BREAKERS
ELECTRICAL
TRIPPING
.
..
3
4
4
4
5
5
MAINTENANCE
INSERTING
SAFETY
PIN
-
AK
-
50
,
AK
-
75
AND
AK
-
100
INSPECTION
TROUBLE
SHOOTING
LUBRICATION
SEPARATION
OF
FRONT
AND
REAR
FRAMES
5
5
6
7
7
7
BASIC
BREAKER
COMPONENTS
ARC
QUENCHERS
POLE
UNIT
ASSEMBLY
OPERATING
MECHANISMS
QUICK
CLOSE
BREAKER
ADJUSTMENTS
AUXILIARY
SWITCH
7
8
13
16
11
23
ELECTRICAL
CLOSING
DEVICES
AND
CONTROLS
CLOSING
SWITCH
CUT
-
OFF
SWITCHES
CONTROL
RELAY
23
23
23
23
PROTECTIVE
DEVICES
STATIC
TIME
DELAY
UNDERVOLTAGE
TRnPING
DEVICE
INSTANTANEOUS
UNDER
VOLTAGE
TRIPPING
DEVICE
.
.
..
UNDERVOLTAGE
LOCKOUT
DEVICE
.
.
.
.
.
.
.
DIRECT
-
ACTING
TRIPPING
DEVICE
-
EC
-
1
B
SERIES
OVERCURRENT
TRIPPING
DEVICE
EC
-
1
SERIES
OVERCURRENT
TRIPPING
DEVICE
EC
-
2
/
EC
-
2
A
.
.
.
REVERSE
CURRENT
TRIPPING
DEVICE
(
AK
-
50
ONLY
)
POWER
SENSOR
TRIP
..
.
.
SELECTIVE
TRIPPING
23
25
25
26
29
31
33
33
39
42
BREAKER
ACCESSORIES
PRIMARY
DISCONNECTS
SECONDARY
DISCONNECTS
DRAWOUT
MECHANISMS
SHUNT
TRIPPING
DEVICE
BELL
ALARM
AND
LOCKOUT
DEVICE
OPEN
FUSE
LOCKOUT
DEVICE
42
42
43
44
44
45
47
MISCELLANEOUS
TOOLS
RENEWAL
’
PARTS
47
47
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
.
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
.
Courtesy of NationalSwitchgear.com

LOW
-
VOLTAGE
POWER CIRCUIT
BREAKERS
Types
AK
-
2
/
3
/
2
A
/
3
A
-
50
/
50
S
AKT
-
2
/
3
/
50
/
50
S
AK
-
2
/
3
/
2
A
/
3
A
-
75
/
75
S
AKU
-
2
/
3
/
2
A
/
3
A
-
50
/
50
S
AK
-
2
/
3
/
2
A
/
3
A
-
100
/
100
S
AKF
-
2
C
/
2
D
/
2
E
OPERATION
INTRODUCTION
MANUAL
CLOSING
For
a
description
of
manual
closing
,
refer
to
the
section
of
these
instructions
entitled
CLOS
-
ING
THE
BREAKER
-
MANUALLY
OPERATED
AK
-
50
and
section
entitled
AK
-
50
-
75
AND
-
100
STORED
ENERGY
MANUAL
MECHANISM
,
both
under
OPERATING
MECHANISMS
.
The
instructions contained herein
are
intended
to
aid
in
the maintenance and
repair
of
basic
breakers
and
accessories
for
AK
-
50
-
75
-
100
Low
Voltage
Power
Circuit
Breakers
.
The basic
AK
-
50
,
AK
-
75
and
AK
-
100
breaker
designs
have
been
expanded
to
include
special
designs
for
specific
applications
.
These
design
extensions have caused
variations
in
the
nomen
-
clature
including
the
following
:
AK
-
2
-
50
,
AK
-
2
-
75
or
AK
-
2
-
100
-
Basic
standard
design
of
breaker
for
stationary
mounting
or
for
drawout
use
in
AKD
type
equipment
.
AK
-
2
A
-
50
,
AK
-
2
A
-
75
,
AK
-
2
A
-
100
-
The
A
indicates
it
has
mounting
features
for
AKD
-
5
type
equipment
.
AK
-
2
-
50
S
,
AK
-
2
-
75
S
,
AK
-
2
-
100
S
-
The
S
indicates breaker
is
equipped
with
a
quick
-
close mechanism which
provides
closing
times
of
approximately
5
cycles
(
.
08
seconds
)
.
AKU
-
2
-
50
fuse
breaker
combination
.
T
_
.
CLOSING
|
“
T
SWITCH
—
—
II
—
11
REMOTE
CLOSE
L
T
*
‘
F
:
|
=
TRIP
I
G
_
IUi
oo
£
C
<
G
±
zF
z
-
i
oo
o
>
L
TRIP
COIL
X
M
LEGEND
*
CLOSING MOTOR
*
RELAY
COIL
+
*
RELAY
CONTACT
FftG
«
=
MECHANICALLY
OPERATED
SWITCHES
+
=
NORMALLY
OPEN
SWITCH
CONTACTS
£
=
NORMALLY CLOSED
SWITCH
CONTACTS
L
-
AUXILIARY
SWITCH
CONTACT
®
X
The
U
indicates
an
internal
SIMPLIFIED
ELEMENTARY
DIAGRAM
INTERNAL
WIRING
AK
—
50
,
75
,
AND
100
AKF
-
2
C
,
AKF
-
2
D
,
AKF
-
2
E
switches
for
use
in
controlling
shunt fields
of
synchronous
motors
and
generators
.
AK
-
2
-
50
H
rupting rating
has been increased
to
the
75
,
000
amp
.
class
.
AK
-
2
-
50
C
,
AK
-
2
-
75
C
-
The
C
indicates
the
interrupting rating
has
been
increased
to
the
100
,
000
amp
.
class
.
AKT
-
2
-
50
continuous
rating
of
2000
amps
.
AK
-
3
-
50
,
AK
-
3
-
75
,
AK
-
3
-
100
indicates
the breaker
is
equipped
with the
Power
Sensor
Overcurrent
Trip
Device
.
AK
-
2
-
50
X
-
The
X
indicates
the breaker
has
very
special
features
or
it
includes
two
or
more
of
the
design
extensions
previously
described
.
When
contacting
the
factory
,
it
is
important
to
furnish the
complete
nameplate
information
.
Are
field
Fig
.
1
.
The
H
indicates
the
inter
-
CLOSING
SWITCH
T
J
_
REMOTE
=
F
CLOSE
ih
-
i
.
v
T
-
E
T
-
G
TD
fi
°
o
<
-
»
>
X
±
F
=
TF
=
4
=
X
W
The
T
indicates
increased
\
cc
<
M
)
r
The
3
LEGEND
CC
-
CLOSING
RELAY
COIL
D
-
CLOSING
RELAY
CONTACTS
E
-
ANTI
-
PUMP
RELAY
CONTACTS
FAG
-
MECHANICALLY
OPERATED
SWITCHES
-
AUXILIARY
SWITCH
CONTACTS
-
CLOSING
MOTOR
-
ANTI
-
PUMP
RELAY
COIL
*
-
CONTROL
RELAY
CONTACTS
X
-
CONTROL
RELAY
COIL
4
:
-
NORMALLY
OPEN
SWITCH
CONTACTS
f
-
NORMALLY
CLOSED
SWITCH
CONTACTS
9
SIMPLIFIED
ELEMENTARY
DIAGRAM
INTERNAL
WIRING
QUICK
CLOSE
BREAKER
Fig
.
1
A
.
3
Courtesy of NationalSwitchgear.com

GEK
-
7303
Low
Voltage
Power
Circuit
Breakers
MANUAL
MAINTENANCE
CLOSING
OF
ELECTRICAL
BREAKERS
An
electrical
breaker
may
be
closed
manually
by
means
of
the
maintenance
handle
furnished
with
the
breaker
.
reach
the
fully
charged
position
,
the
mechanically
operated
switches
operate
,
reversing
their
contacts
.
Upon
operation
of
these
switches
the
motor
is
stopped
by
the
opening
of
the
G
switch
.
The
closing
of
the
F
switch
prepares
the
breaker
for
a
closing
operation
.
To
observe
the
operation
of
the
breaker
with
-
out
power
,
with
the
breaker
open
and
springs
discharged
,
proceed
as
follows
:
1
.
Charge
the
closing
spring
with
the
main
-
tenance
handle
(
1
,
Fig
.
3
)
until
the
indica
-
tor
reads
"
charged
”
.
2
.
Continue
to
operate
the
maintenance
handle
until
the
breaker
closes
.
3
.
Open
the
breaker
by
pushing
the
trip
button
(
4
,
Fig
.
2
)
.
ELECTRICAL
CLOSING
The
electrical
control
system
is
comprised
of
an
X
relay
,
two
double
contact
mechanically
operated
switches
(
F
and
G
)
,
a
push
button
closing
switch
and
any
means
for
remote
closing
which
the
user
may
incorporate
into
the
system
.
When
voltage
is
first
applied
to
the
breaker
,
(
before
any
closing
signal
is
given
)
the
motor
is
energized
through
two
of
the
X
relay
contacts
and
the
two
G
switch
contacts
.
The
motor
then
compresses
the
closing
springs
to
the
"
pre
-
charged
"
position
at
which
point
the
mechanically
operated
F
and
G
switches
are
operated
.
This
opens
the
G
contacts
,
stopping
the
motor
,
and
closes
the
F
contacts
,
which
readies
the
system
for
the
actual
closing
of
the
breaker
.
When
the
push
button
or
remote
switch
signals
for
a
closing
operation
,
the
X
relay
coil
is
energized
,
operating
the
X
contacts
.
This
seals
in
the
X
relay
and
energizes
the
motor
once
again
and
the
closing
operation
takes
place
.
QUICK
CLOSE
FOR
ELECTRICAL
BREAKERS
Functionally
,
the
quick
close
mechanism
differs
from
the
standard
electrical
mechanism
in
that
the
pre
-
charge
operation
is
extended
to
completely
charge
the
closing
springs
.
At
the
end
of
the
charg
-
ing
operation
,
which
takes
approximately
5
seconds
,
a
latch
plate
engages
the
prop
roller
to
prevent
the
closing
springs
from
discharging
.
With
the
closing
springs
fully
charged
the
breaker
is
ready
for
a
closing
operation
upon
release
of
the
prop
roller
.
This
may
be
accom
-
plished
either
manually
,
by
depressing
the
closing
lever
on
the
breaker
,
or
electrically
by
closing
the
remote
closing
switch
.
Upon
the
release
of
the
prop
roller
the
closing
springs
discharge
and
close
the
breaker
in
the
same
manner
as
on
the
standard
electrical
breaker
.
Fig
.
2
(
8039671
)
Front
view
of
AK
-
2
-
50
breaker
1
.
Auxiliary
Switch
2
.
Position
Indicator
3
.
Relay
4
.
Manual
Trip
Button
5
.
Shaft
for
Manual
Mainte
-
nance
Closing
Handle
6
.
Spring
Charged
-
Discharged
Indicator
7
.
Motor
Cut
-
off
Switches
8
.
Arc
Quenchers
A
closing
signal
now
given
energizes
the
control
relay
X
whose
contacts
close
and
complete
the
circuit
through
the
closing
relay
coil
.
With
the
closing
relay
coil
energized
the
breaker
closes
as
described
above
.
At
the
same
time
the
closing
relay
contact
closes
to
energize
the
anti
-
pump
relay
causing
its
contacts
to
reverse
providing
the
anti
-
pump
feature
.
When
the
breaker
closes
,
the
mechanical
opera
-
ted
G
switches
close
to
energize
the
motor
again
and
the
F
switches
open
and
de
-
energize
the
con
-
trol
relay
from
being
energized
until
the
breaker
is
tripped
open
.
With
the
G
switches
closed
,
the
motor
charges
the
closing
springs
ready
for
the
next
closing
operation
.
With
control
voltage
applied
,
the
motor
is
energized
through
the
G
switch
contacts
,
and
charges
the
closing
springs
.
When
the
springs
4
Courtesy of NationalSwitchgear.com

Low
Voltage
Power
Circuit
Breakers
GEK
-
7303
ELECTRICAL
TRIPPING
The
breaker
may
be
tripped
electrically
by
any
of
the
electrical
tripping
devices
described
in
these
instructions
,
tripped
by
the automatic
overcurrent
or
reverse
current
tripping
devices
,
if
so
equipped
,
these
devices
trip
the
breaker
in
a
similar
manner
,
i
.
e
.
the
device
trip
arm
moves
against
the
trip
paddles
fastened
on
the
trip
shaft
,
thus
rotating
the
trip
shaft and
displacing
the
trip
latch
.
The
most
commonly
used
tripping
device
is
the
shunt
trip
device connected
in
the control circuit
as
shown
in
Fig
.
1
.
When
a
tripping signal
is
given
,
the shunt
trip
coil is
energized through
a
norftially
-
open
auxiliary
switch
"
a
”
contact
,
thus
tripping
the
breaker
.
The
breaker
may
also
be
All
MAINTENANCE
BEFORE INSPECTION OR
ANY
MAINTENANCE
WORK IS
DONE
BE
SURE
THAT
THE
BREAKER
IS
IN
THE
OPEN POSITION
.
ALL
ELECTRICAL
POWER
,
BOTH
PRIMARY
AND
CONTROL
SOURCES
,
SHOULD
ALSO
BE
DISCONNECTED
.
Fig
.
3
(
8039670
)
View
showing
operation
of
AK
-
2
-
50
breaker
with
manual
maintenance
handle
and
installation
of
safety
pin
Warning
:
ergy
closing
mechanisms
,
care
must
be
taken
when the
circuit
breaker
is
being
installed
and when
any
inspection
or
maintenance
work
is
being
done
so
that
the breaker
is
in
the
open
position
and the
closing
springs
are
being
restrained
by
the
safety
pin
.
The
proce
-
dure
for
inserting
the
safety
pin
is
given
below
.
INSERTING
SAFETY
PIN
AK
-
50
,
-
75
and
-
100
(
Fig
.
3
)
The
closing
spring
should
be
charged
with
the
maintenance
handle
(
1
)
so
that
the
safety
pin
(
3
)
can
be
placed
in
the hole
of
the
push
rod
(
2
)
.
Continue
to
operate
the maintenance handle
,
clos
-
ing
the breaker
.
This is done
so
that
the
safety
pin
takes
the
spring
force
.
To
install the
safety
pin
of
the
manual
stored
-
energy
mechanism
refer
to
the section entitled
STORED
-
ENERGY
MANUAL
MECHANISM
on
page
17
of
these
instructions
.
With
the
safety
pin
restraining
the
closing
spring
force
,
the
contacts
will close
slowly
when
the
breaker
is
manually
operated
allowing
the
operation
of
the mechanism and the
contact
align
-
ment to
be
visually
observed
.
On
breakers
employing
stored
-
en
-
1
.
Manual maintenance Handle
2
.
Push Rod
3
.
Safety
Pin
INSPECTION
Periodic
inspection
of
the circuit breaker is
recommended
at
least
once
a
year
.
More
fre
-
quent
inspections
are
recommended
if
severe
load conditions
,
dust
,
moisture
or
other
unfavor
able conditions
exist
,
of
the breaker
,
including
contacts
and
arc
quenchers
,
should
always
be made
after
the breaker
has
in
-
terrupted
a
short
-
circuit
.
At
regular
inspection
periods
the
breaker
should
be
operated
manually
;
(
stored
energy
mechanisms
with the
safety
pin
restraining
the
closing
spring
force
)
to
observe the
contact
alignment
and
to
make
sure
all
mechanism
parts
move
freely
without
binding
or
excessive
friction
.
If
the
breaker remains
open
or
closed
for
a
period
of
six
months
or
more
,
it
is recommended
that
arrangements
be
made
to
open
and close
it
several
times
in
succession
,
preferably
under
load
.
A
complete
inspection
Following
the
inspection
period
,
the
closing
springs
must
be
recharged
,
the
safety
pin
removed
from
the
push
rod
,
and
the
pin
placed
in
the retain
-
ing
spring
clip
adjacent
to
Hie
push
rod
.
If
overheating
,
not
caused
by
overcurrent
,
is
observed
,
a
complete
inspection
of
the breaker
should be
made
including
connections
and
contacts
.
5
Courtesy of NationalSwitchgear.com

GEK
-
7303
Low
Voltage
Power
Circuit
Breakers
TROUBLE
SHOOTING
1
REMEDY
CAUSE
TROUBLE
Overheating
Contacts
not
aligned
.
Contacts
dirty
,
greasy
or
coated
with
dark
film
.
Adjust
contacts
.
Clean
contacts
.
Replace
contacts
.
Clean
surfaces of
current
-
carrying
parts
.
Relocate
or
provide adequate
enclosure
.
Increase
capacity
of
bus
or
cable
.
Tighten
,
but
do
not
exceed
,
elastic
limit
of
bolts
or
fittings
.
Check
breaker
application
or
modify
circuit
by
decreasing
load
.
Provide
adequate
ventilation
.
Correct
bus
or
cable
arrangement
.
Contacts
badly
burned
or
pitted
.
Current
-
carrying
surfaces
dirty
.
Corrosive
atmosphere
.
Insufficient bus
or
cable
capacity
.
Bolts
and
nuts
at
terminal connections
not
tight
.
Current
in
excess
of
breaker
rating
.
Excessive ambient
temperature
.
Inductive
heating
.
Failure
to
Trip
AK
-
2
Breakers
Travel
of
tripping
device does
not
provide
positive
release
of
tripping
latch
.
Worn
or
damaged
trip
unit
parts
.
Binds
in
overcurrent
trip
device
.
Re
-
adjust
or
replace
tripping
device
.
Replace trip
unit
.
Replace
overcurrent
trip
device
.
Loose
or
Disconnected
Power
Sensor
Disconnect
Plugs
.
Tighten
or
Reconnect
Disconnect
Plugs
.
Tighten
or
Reconnect
Tap
Connections
.
Failure
to
Trip
AK
-
3
Breakers
Loose
or
Broken
Power
Sensor
Coil
Tap
Connections
.
)
Check
application
of
overcurrent
trip
device
.
Check
application
of
overcurrent
trip
device
.
Replace
overcurrent
trip
device
.
False
Tripping
AK
-
2
Breakers
Overcurrent
pick
up
too
low
.
Overcurrent
time
setting
too
short
.
Bind
in
overcurrent
trip
device
.
Tighten Thumb
Screw
on
Desired
Setting
.
Captive
Thumb
Screw
on
Power
Sensor
Loose
Fail
-
Safe
Circuitry
Reverts
Characteristic
to
Minimum
Setting
and Maximum Time
Delay
.
Tap
Setting
Dial
on
Power
Supply
Incorrectly
Set
.
External
Ground
Sensor
Coil
Improperly
Connected
.
Set
Dial
to
Correspond
with
Power
Sensor
Coil
Tap
.
Refer
to
Fig
.
40
Page
38
for
Polarity
and
Connections
.
Check
Continuity
of
Shield
and
Conductors
Connecting
the
External
Ground
Sensor
Coil
False
Tripping
AK
-
3
Breakers
Failure
to
Close
and Latch
Re
-
align and
adjust
attachments
.
Binding
in
attachments
preventing
resetting
of
latch
.
Latch
out
of
adjustment
.
Latch
return
spring
too
weak
or
broken
.
Hardened
or
gummy
lubricant
.
Safety
pin
left
in
push
rod
..
Motor
burned
out
.
Adjust
latch
.
Replace
spring
.
Clean
bearing
and
latch
surfaces
.
Remove
safety
pin
.
Replace
motor
.
Replace
or
adjust
faulty
device
.
Faulty
control circuit
component
.
Improper
contact
sequence
(
main
contacts
not
sufficiently
parted
when
arcing
contacts
part
)
.
Short
-
circuit
current
level
above inter
-
rupting rating
of
breaker
.
Burned
Main
Contacts
Increase
arcing
contact
wipe
.
Adjust
contact
sequence
by
raising
or
lower
-
ing
main
movable
contact
pivot
block
.
Requires
system
study
and
possible
replacement
with
breaker
having
ade
-
quate
interrupting
capacity
.
Replace
stationary
contact
springs
and
dress
up
or
replace
contacts
.
J
Loss
of
contact
wipe
or
pressure
.
6
Courtesy of NationalSwitchgear.com

Low
Voltage
Power
Circuit
Breakers
GEK
-
7303
5
.
Remove
the
auxiliary
switch
operating
rod
(
&
,
Fig
.
20
)
.
At
all
times
it
is
important
not
to
permit
pencil
lines
,
paint
,
oil
or
other
foreign
mater
-
ials
to
remain
on
the
insulating
surfaces
of
the
breaker
as
they
may
cause
low
resistance
between
points
of
different
potential
and
result
in
eventual
electrical
breakdown
.
6
.
Check
along
the
trip
shaft
for
a
mech
-
anical
interference
or
connection
between
the
overcurrent
trip
device
and
the
trip
paddles
.
Remove
mechanical
connection
if
present
,
or
if
interference
exists
,
use
extreme
care
when
removing
or
re
-
assembling
front
and
back
frames
to
avoid
mechanical
breakage
of
trip
devices
.
In
reassembling
the
front
and
rear
frames
,
the
two
frames
should
be
positioned
vertically
so
that
the
trip
shaft
is
horizontally
aligned
.
NOTE
:
be
fastened
to
a
suitable
maouting
base
with
the
front
frame
supported
by
a
sling
or
hook
as
the
bolts
are
being
installed
.
The
breaker
should
be
operated
several
times
at
a
rated
voltage
to
assure
that
the
control
circuits
are
properly
connected
and
that
all
electrical
attachments
are
functioning
properly
.
A
complete
contact
inspection
,
including
con
-
tact
wipe
and
pressure
,
should
be
made
at
regu
-
lar
inspection
periods
and
always
after
a
known
short
circuit
current
has
been
interrupted
,
to
determine
whether
the
contacts
are
worn
or
pitted
in
which
case
they
should
be
dressed
or
replaced
.
It
is
necessary
to
remove
the
arc
quenchers
to
properly
inspect
the
contacts
.
Arc
-
ing
contacts
and
arc
quencher
barriers
should
be
replaced
when
they
are
eroded
to
half
their
original
thickness
.
It
is
recommended
that
the
breaker
BASIC
BREAKER
COMPONENTS
ARC
QUENCHERS
(
Fig
.
4
and
5
)
The
arc
quenchers
should
be
inspected
at
the
If
the
barriers
are
LUBRICATION
regular
inspection
period
,
cracked
or
eroded
to
one
-
half
their
original
thickness
,
they
should
be
replaced
.
In
general
,
the
circuit
breaker
requires
mod
-
Mechanical
bearing
points
erate
lubrication
,
and
sliding
surfaces
should
be
lubricated
at
the
regular
inspection
periods
with
a
thin
film
of
G
-
E
Lubricant
D
50
H
15
.
Sliding
silver
plated
con
-
tact
surfaces
should
be
lubricated
with
G
-
E
Lub
-
ricant
D
50
H
47
.
Hardened
grease
and
dirt
should
be
removed
from
latch
and
bearing
surfaces
by
using
kerosene
.
ALL
EXCESS
LUBRICANT
SHOULD
BE
REMOVED
TO
AVOID
ANY
ACCUMULATION
OF
DIRT
OR
DUST
.
REPLACEMENT
—
AK
BREAKERS
Be
sure
the
breaker
is
open
.
1
.
2
.
Remove
the
channel
-
shaped
retaining
bar
by
removing
two
screws
and
two
nuts
.
3
.
Lift
the
quenchers
clear
of
the
movable
arcing
contacts
.
4
.
During
replacement
be
careful
not
to
overtighten
the
screw
which
secure
the
channel
-
shaped
retaining
bar
.
Overtightening
the
screws
will
bow
the
bar
and
leave
the
center
arc
quen
-
cher
loose
.
The
use
of
cotton
waste
to
wipe
bearing
surfaces
should
be
avoided
,
as
the
cotton
ravelings
may
become
entangled
under
the
bearing
surfaces
and
destroy
the
surface
of
the
bearing
.
On
drawout
breakers
,
the
contact
surface
of
the
disconnect
studs
should
be
greased
with
G
-
E
Grease
Specification
D
50
H
47
.
SEPARATION
OF
FRONT
AND
REAR
FRAMES
To
repair
or
replace
contacts
,
operating
mech
-
anism
,
or
the
overcurrent
devices
,
the
front
frame
must
be
separated
from
the
back
frame
.
To
separate
the
two
frames
proceed
as
follows
:
1
.
The
breaker
contacts
must
be
open
with
the
safety
pin
in
place
.
(
See
MAINTENANCE
.
)
2
.
Remove
the
two
opening
springs
(
on
lower
part
of
the
breaker
)
from
the
outside
pole
units
.
3
.
Remove
the
clevis
pin
(
14
,
Fig
.
6
)
(
13
,
Fig
.
7
)
from
the
center
pole
unit
.
4
.
Remove
the
six
nuts
from
the
back
frame
using
a
socket
wrench
with
an
extension
.
These
include
the
two
nuts
at
the
top
of
the
frame
.
REPLACEMENT
—
AKF
BREAKERS
The
center
-
pole
arc
quencher
of
these
breakers
is
similar
to
the
arc
quenchers
of
the
standard
breakers
and
is
replaced
in
a
similar
manner
,
except
that
the
breaker
must
be
closed
.
With
the
breaker
closed
the
center
-
pole
contacts
are
open
and
the
arc
quencher
can
be
removed
.
Replace
the
outer
-
pole
arc
quenchers
of
the
Type
AKF
breaker
as
follows
:
1
.
Be
sure
the
breaker
is
open
.
2
.
Remove
the
two
channel
-
shaped
retaining
bars
which
bear
against
the
front
of
the
arc
quenchers
by
removing
four
screws
,
two
on
each
side
.
3
.
Lift
the
arc
quenchers
clear
of
the
movable
arcing
contacts
.
4
.
Replace
arc
quenchers
and
insert
the
four
screws
holding
the
retaining
bars
in
position
.
7
Courtesy of NationalSwitchgear.com

GEK
-
7303
Low
Voltage
Power
Circuit
Breakers
9
8
7
6
Fig
.
4
(
8014830
)
Disassembly
of
arc
quenchers
-
standard
breaker
and
AKF
center
pole
.
6
.
Muffler
7
.
Compound
Support
8
.
Steel
Back
Plate
9
.
Spacer
Block
1
.
Stud
2
.
Cap
3
.
Side
Barrier
4
.
Pocket
Barrier
5
.
Inner
Barrier
DISASSEMBLY
—
AK
AND
AKF
CENTER
POLE
(
Fig
.
4
)
The
following
instructions
apply
to
both
tne
Type
AK
and
AKF
breaker
center
poles
.
3
.
Remove
bolt
fastening
cap
(
4
)
and
barrier
plate
assembly
.
4
.
Barrier
plates
may
now
be
lifted
from
as
-
sembly
for
inspection
.
5
.
In
reassembling
,
make
sure
components
are
positioned
so
that
holes
for
self
-
tapping
hard
-
ware
are
in
line
.
Do
not
strip
threads
in
compound
by
overstressing
screws
.
1
.
Remove
arc
quenchers
(
see
REPLACE
-
MENT
)
.
2
.
Remove
screws
holding
spacer
block
(
9
)
.
3
.
Remove
spacer
block
,
steel
back
plate
(
8
)
,
and
compound
support
(
7
)
.
4
.
Rock
muffler
(
6
)
slightly
and
remove
.
The
inner
barriers
(
5
)
can
now
be
removed
for
inspection
.
5
.
Remove
nut
and
withdraw
stud
(
1
)
.
6
.
Remove
cap
(
2
)
.
The
side
(
3
)
and
pocket
(
4
)
barriers
should
be
free
.
7
.
Reassemble
and
replace
the
arc
quencher
in
the
reverse
order
.
Tighten
the
fastenings
after
replacement
.
POLE
UNIT
ASSEMBLY
(
Fig
.
6
)
NOTE
:
The
text
and
part
identification
numbers
contained
in
this
section
apply
to
illustrations
covering
the
AK
-
50
breaker
.
The
same
text
is
applicable
to
the
AK
-
75
and
100
breakers
by
referring
to
Fig
.
7
and
identifying
the
similar
parts
.
These
similar
parts
may
not
,
in
every
case
,
be
identified
by
the
same
number
.
Each
pole
unit
assembly
consists
of
a
set
of
arcing
contacts
,
a
set
of
main
contacts
,
the
actuating
linkage
and
the
mounting
base
.
Fig
.
8
and
9
,
pole
unit
assemblies
mounted
on
back
frame
assemblies
.
See
DISASSEMBLY
—
AKF
OUTER
POLES
(
Fig
.
5
)
1
.
Remove
arc
quenchers
(
see
above
)
and
lay
on
sides
on
a
flat
surface
.
The
stationary
arcing
-
contact
assembly
con
-
sists
of
a
set
of
parallel
contact
fingers
(
2
)
,
pin
(
3
)
,
and
compression
springs
(
22
)
,
which
provide
continuous
contact
pressure
for
the
full
2
.
Remove
hardware
from
one
side
of
arc
quencher
as
indicated
in
Fig
.
5
.
8
Courtesy of NationalSwitchgear.com

GEK
-
7303
Low
Voltage
Power
Circuit
Breakers
I
*
I
I
J
1
2
a
Figo
5
(
8019408
)
Disassembled
arc
quencher
-
AKF
outer
poles
.
1
.
Muffler
Assembly
2
.
Spacer
Block
3
o
Inner
Barrier
4
.
Cap
5
.
Intermediate
Barrier
6
.
Outer
Barrier
7
.
Side
Plate
Steel
springs
(
5
)
shunt
travel
of
the
contacts
,
the
pivot
pin
to
prevent
possible
pitting
at
the
pivot
point
when
interrupting
high
currents
.
On
earlier
model
breakers
flexible
braid
leads
were
used
.
In
order
to
function
properly
,
a
definite
amount
of
contact
pressure
and
contact
wipe
must
exist
between
the
movable
and
stationary
contacts
.
Table
I
gives
the
figures
for
contact
pressure
and
contact
wipe
.
Both
wipe
and
pressure
should
be
checked
during
the
regular
inspection
period
.
MEASURING
CONTACT
WIPE
(
Fig
.
6
)
1
.
Remove
arc
quenchers
(
see
REPLACEMENT
under
ARC
QUENCHER
)
.
2
.
With
the
breaker
open
,
measure
the
hori
-
zontal
distance
from
the
edge
of
the
stationary
contact
to
the
stationary
block
behind
it
.
(
"
B
”
dim
.
for
arcing
contacts
,
”
C
"
dim
.
for
main
contacts
)
.
The
movable
arcing
-
contact
assembly
consists
of
parallel
contact
arms
(
4
)
carried
on
two
mov
-
able
pivot
pins
(
8
)
and
(
19
)
.
The
arcing
contacts
interleave
the
main
contacts
and
pivot
with
them
about
pin
(
19
)
.
This
relative
motion
is
obtained
by
linkages
from
the
upper
pin
(
7
)
to
the
breaker
mechanism
.
The
stationary
main
contact
assembly
includes
main
and
intermediate
contacts
.
The
intermediate
-
contact
surface
extends
beyond
the
main
contacts
and
will
,
therefore
,
make
before
the
main
contacts
and
break
after
the
main
contacts
.
The
number
of
contacts
for
each
breaker
rating
is
given
in
Table
I
.
Close
the
breaker
and
repeat
item
2
.
The
difference
between
the
readings
in
items
2
and
3
determines
the
wipe
of
the
contacts
.
For
safety
reasons
be
extremely
careful
not
to
trip
the
breaker
.
3
.
The
movable
main
contacts
pivot
around
a
stationary
pin
(
18
)
,
which
holds
them
to
the
lower
block
.
Motion
is
obtained
from
a
second
pin
(
7
)
,
connected
by
an
insulated
link
(
12
)
to
th
.
e
breaker
mechanism
.
In
addition
to
steel
springs
shunting
the
current
from
the
contact
directly
to
the
lower
contact
block
,
steel
springs
(
17
)
force
the
contacts
against
the
pins
to
prevent
pitting
at
the
pivot
point
.
The
movable
main
contact
assembly
also
contains
main
and
intermediate
contacts
.
MEASURING
CONTACT
PRESSURE
(
Fig
.
6
)
1
.
Remove
arc
quenchers
(
see
REPLACEMENT
UNDER
ARC
QUENCHER
)
.
2
.
Close
the
breaker
and
measure
dimension
”
BTT
.
3
.
Open
the
breaker
.
Place
a
push
-
type
scale
9
Courtesy of NationalSwitchgear.com

Low
Voltage
Power
Circuit
Breakers
GEK
-
7303
TABLE
I
Intermediate
Contacts
Arcing
Contacts
Main
Contacts
Pres
-
sure
in
Lbs
.
Wipe
No
.
of
Zontacts
Per
Pole
Wipe
No
.
of
Contacts
Per
Pole
Pres
-
sure
In
Lbs
.
Wipe
No
.
of
in
Contacts
Inches
/
Per
Pole
Pres
-
sure
in
Lbs
.
Breaker
Type
in
in
Inches
Inches
4
/
64
to
12
/
64
to
18
/
64
12
/
64
to
18
/
64
12
/
64
to
18
/
64
12
/
64
to
18
/
64
12
/
64
to
18
/
64
12
/
64
to
18
/
64
12
/
64
to
18
/
64
AK
-
50
for
AC
3
55
to
65
31
to
43
55
to
65
2
1
*
7
/
64
1
/
16
to
AK
-
50
for
DC
3
3
31
to
43
55
to
65
55
to
65
1
7
/
64
1
/
16
to
AK
-
75
for
AC
35
to
45
35
to
45
31
to
43
5
3
1
7
/
64
1
/
16
to
AK
-
75
for
DC
35
to
45
5
35
to
45
5
31
to
43
1
*
7
/
64
1
/
16
to
AK
-
100
for
AC
AK
-
100
for
DC
8
25
to
35
25
to
35
31
to
43
2
5
7
/
64
1
/
16
to
AKF
-
2
C
3
55
to
65
55
to
65
2
31
to
43
1
*
7
/
64
(
Outside
Poles
)
25
to
35
1
/
16
to
AKF
-
2
D
(
Outside
AKF
-
2
E
(
Poles
)
55
to
65
31
to
43
5
3
1
7
/
64
AKF
-
2
C
(
Field
AKF
-
2
D
Discharge
Contacts
)
28
/
64
to
40
/
64
0
10
to
16
0
2
*
*
*
The
intermediate
contact
wipe
should
be
at
least
1
/
16
in
.
greater
than
main
contact
wipe
.
*
*
Left
stationary
contact
extends
approximately
3
/
32
in
.
±
1
/
32
further
than
right
hand
contact
.
against
the
stationary
arcing
contacts
at
a
point
measured
in
line
with
the
break
between
the
contact
stop
and
the
contact
pivot
block
.
Push
the
contact
backward
until
dimension
"
B
"
recorded
in
item
2
is
reached
.
effect
.
5
.
To
increase
the
wipe
on
either
outside
pole
individually
,
move
the
crossbar
adjusting
plate
of
that
pole
to
the
left
;
to
decrease
the
wipe
move
the
adjusting
plate
to
the
right
.
The
scale
should
then
be
read
.
4
.
If
the
pressure
is
not
within
the
require
-
ments
listed
on
TABLE
I
,
refer
to
the
section
of
these
instructions
dealing
with
ADJUSTING
CONTACT
WIPE
AND
PRESSURE
.
ADJUSTING
CONTACT
WIPE
AND
PRESSURE
(
Fig
.
6
)
1
.
To
obtain
proper
contact
wipe
and
pressure
on
the
center
pole
,
dimension
"
A
"
should
be
increased
to
increase
wipe
and
decreased
to
decrease
wipe
.
2
.
To
change
dimension
"
A
"
remove
the
clevis
pin
(
14
)
and
rotate
the
clevis
as
necessary
.
3
.
To
prevent
overstressing
the
clevis
threads
(
13
)
dimension
,
TAft
should
not
exceed
3
/
16
in
.
and
space
"
A
"
should
be
filled
with
shims
to
0.005
in
.
of
being
solid
.
4
.
With
the
proper
center
pole
wipe
obtained
,
moving
the
crossbar
adjusting
plate
(
10
A
)
center
pole
to
the
right
will
simultaneously
in
-
crease
the
wipe
on
both
outside
poles
;
moving
the
adjusting
plate
to
the
left
will
have
the
reverse
If
the
proper
contact
pressure
NOTE
:
does
not
exist
when
the
contact
wipe
is
within
its
limits
,
the
stationary
contacts
springs
should
be
replaced
.
CONTACT
SEQUENCE
(
Fig
.
6
)
On
the
horizontal
plane
,
the
difference
in
the
making
of
the
arcing
contacts
on
the
same
pole
must
be
no
greater
than
1
/
32
in
.
;
the
difference
be
-
tween
arcing
contacts
on
separate
poles
1
/
16
in
.
If
it
is
desired
to
advance
or
retard
the
closing
of
the
main
contacts
of
a
pole
,
loosen
the
bolts
holding
the
adjustment
plate
(
10
A
)
of
that
pole
and
slide
plate
to
the
left
to
advance
contact
closing
,
or
to
the
right
to
retard
contact
closing
Make
this
adjustment
on
the
outer
poles
,
using
the
center
pole
as
a
reference
.
Upon
retight
-
ening
adjustment
plate
bolts
,
make
sure
the
lock
-
ing
tabs
are
turned
up
around
bolt
heads
,
locking
the
bolts
securely
in
place
.
on
the
Contact
sequence
in
the
vertical
plane
should
be
such
that
when
the
arcing
contacts
are
just
touching
,
the
intermediate
contact
gap
should
be
10
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