GE AM-13.8-750-5 User manual

INSTRUCTIONS
AND
RECOMMENDED
PARTS
FOR
MAINTENANCE
GEK
-
7345
D
Supersedes
GEK
-
7345
C
MAGNE
-
BLAST
CIRCUIT
BREAKER
I
.
)
TYPE
AM
-
13.8
-
750
-
5
1200
&
2000
AMPERE
W
/
ML
-
13
MECHANISM
INTRODUCTION
3
RECEIVING
,
HANDLING
AND
STORAGE
3
INSTALLATION
4
DESCRIPTION
OF
OPERATION
..
.
4
ADJUSTMENTS
10
GENERAL
MAINTENANCE
15
it
RENEWAL
PARTS
28
GENERAL
ELECTRIC
Courtesy of NationalSwitchgear.com

•
!
;
I
Courtesy of NationalSwitchgear.com

MAGNE
-
BLAST
CIRCUIT
BREAKER
AM
-
13.8
-
750
-
5
(
A
)
-
6
A
Letter
designation
B
,
C
,
F
,
H
,
J
,
L
,
N
,
&
P
used
immediately
following
the
model
number
indicates
basic
design
features
.
INTRODUCTION
The
Magnerblast
Breaker
is
the
removable
and
interchangeable
interrupting
element
used
in
metal
-
clad
switchgear
to
provide
reliable
control
and
protection
of
electrical
apparatus
and
power
systems
.
be such
that
its
voltage
,
current
,
and
interrupting
ratings
are never
exceeded
,
is
written
to
include
all
ratings
of
the
breaker
as
well
as
several
design
variations
,
the
in
-
structions
will
be
of
a
general
character
and
all
illustrations
will
be
typical
unless
otherwise
specified
.
PROPER
INSTALLATION
AND
MAINTENANCE
ARE
NECESSARY
TO
INSURE
CONTINUED
SAT
-
ISFACTORY
OPERATION
OF
THE
BREAKER
.
The
following
instructions will
provide
complete
information
for
placing
magne
-
blast
breakers
in
service
and
for
maintaining
satisfactory
operation
.
Since
this
book
The
AM
-
13.8
-
750
Magne
-
blast
Breaker
is
available
with
continuous
current
ratings
of
1200
amperes
and
2000
amperes
in
accordance
with
applicable
industry
standards
.
Refer
to
the
breaker
nameplate
for
complete
rating
information
of
any
particular
breaker
.
The
nameplate
also
de
-
scribes
the
control
power
requirements
for
that
breaker
.
The
application
of
a
breaker
must
RECEIVING
,
HANDLING
AND
STORAGE
Receiving
and
Handling
against
condensation
,
preferably
by
stor
-
ing
it
in
a
warm
dry
room
,
since
water
absorption
has
an
adverse
effect
on
the
insulation
parts
.
Circuit
breakers
for
out
-
door
metal
-
clad
switchgear
should
be
stored
in
the
equipment
only
when
power
is
available
and the
heaters
are
in
oper
-
ation
to
prevent
condensation
.
2
.
The
breaker should
be
stored
in
a
clean
location
,
free
from
corrosive
gases
or
fumes
;
particular
care
should
be
taken
to
protect
the
equipment
from
moisture
and
cement
dust
,
as
this
combination
has
a
very
corrosive
effect
on
many
parts
.
3
.
Unfinished
surfaces of
rollers
,
latches
,
etc
.
,
of
the
operating
mechanism
should
be
coated
with
grease
to
prevent
rusting
.
If
the breaker
is
stored
for
any
length
of
time
,
it
should
be
inspected
periodically
to
see
that
rusting
has
not
started and
to
insure
good
mechan
-
ical
condition
.
Should
the breaker be
stored under
unfavorable
atmospheric
conditions
,
it
should
be cleaned
and
dried
out
before
being
placed
in
service
.
Each
breaker
is
carefully
inspected
and
packed
for
shipment
.
Immediately
upon
receipt
of
the
circuit
breaker
,
an
examination
should be
made
for
any
damage
sustained
in
transit
.
If
injury
or
rough
handling
is evident
,
a
damage
claim
should be
filed
immediately
with
the
transportation
company
and the
nearest
General
Electric
Sales
Office
should
be
notified
.
It
is
expected
that
due
care
will
be
exercised
during
the
unpacking
and
installation
of
the breaker
so
that
no
damage
will
occur
from
careless
or
rough
handling
,
or
from
exposure
to
moisture
or
dirt
.
Check
all
parts
against
the
packing
list
to
be
sure
that
no
parts
have
been
overlooked
.
Storage
It
is
recommended
that
the
breaker
be
put
into
service
immediately
in
its
permanent
location
.
If
this
is
not
possible
,
the
following
precautions
must
be
taken
to
insure
the
proper
storage
of
the
breaker
;
1
.
The
breaker
should
be
carefully
protected
Cover
Photo
(
8034807
)
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
,
but
no
such
assurance
is
given
with
respect
to
local
codes
and
ordinances
because
they
vary
greatly
.
Should
IEEE
and
NEMA
standards
;
3
'
.
:
'
L
-
Courtesy of NationalSwitchgear.com

r
-
V
'
V
'
'
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'
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;
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f
GEK
-
7345
Magne
-
Blast
Circuit
Breaker
INSTALLATION
Each
breaker
has
been
tested
and
inspected
before
shipment
from
the
factory
;
however
,
before
placing
the
breaker
in
service
the
following
items
should
be
checked
to
assure
that
no
change
has
oc
-
curred
during
shipment
and
storage
.
BEEN
TRIPPED
OPEN
OR
MECHANICALLY
BLOCKED
.
THIS
PRECAUTION
IS
REQUIRED
TO
PREVENT
ACCIDENTAL
CLOSING
OR
TRIPPING
The
closing
springs
should
now
be
unblocked
.
Ro
-
tate
the
driving
eccentric
until
the
indicator
reads
"
CHARGED
”
and
the
ratchet
wheel
does
not
advance
.
The
spring
blocking
device
can
now
be
removed
.
1
.
Remove
the
box
barriers
and
mechanism
cover
and
make
a
visual
inspection
to
ascertain
that
the
breaker
and
mechanism
is
in
satisfactory
condition
.
Check
all
bearing
surfaces
of
the
mechanism
for
lubrication
.
Refer
to
section
on
LUBRICATION
page
17
and
Figure
17
.
3
.
To
assure
that
the
electrical
connections
have
remained
tight
,
they
should
be
checked
during
installation
as
well
as
during
each
maintenance
in
-
spection
.
This
check
of
electrical
connections
is
particularly
necessary
on
breakers
used
in
nuclear
generating
stations
and
other
critical
applications
.
The
bolted
braid
connections
on
the
stationary
arcing
contacts
should
be
checked
for
tightness
by
removing
the
arc
chutes
as
described
on
page
15
.
4
.
Connect
the
test
coupler
to
the
circuit
breaker
and
operate
it
electrically
several
times
.
Check
the
control
voltage
as
described
under
"
CONTROL
POWER
CHECK
"
(
Page
14
)
.
2
.
Charge
the
breaker
closing
springs
manually
using
a
5
/
8
”
ratchet
wrench
to
turn
the
driving
ec
-
centric
(
4
)
Figurel
.
Turning
the
eccentric
counter
-
clockwise
will
advance
the
ratchet
wheel
and
com
-
press
the
springs
.
When
the
springs
have
reached
the
fully
charged
position
the
indicator
(
1
)
will
read
"
CHARGED
”
,
and
the
driving
pawl
will
be
raised
from
the
ratchet
wheel
teeth
.
Additional
turning
of
the
eccentric
will
not
advance
the
ratchet
wheel
.
5
.
Disconnect
the
test
coupler
and
before
replacing
the
box
barrier
,
the
primary
bushings
and
other
insulation
should
be
wiped
clean
.
Insert
the
spring
blocking
device
(
6
)
and
manually
discharge
the
springs
against
the
pins
by
pushing
the
manual
release
button
(
3
)
.
The
springs
are
now
blocked
and
slow
closing
of
the
breaker
contacts
can
be
accomplished
by
again
turning
the
driving
eccen
-
tric
with
a
5
/
8
”
ratchet
wrench
.
6
.
If
the
breaker
has
been
stored
for
a
long
period
of
time
,
it
is
recommended
that
the
insulation
be
checked
with
a
standard
60
hertz
high
potential
test
.
Refer
to
Insulation
Test
(
Page
17
)
.
NOTE
:
If
the
breaker
secondary
wiring
is
to
be
given
a
hi
-
potential
test
at
1500
volts
,
remove
both
the
motor
leads
from
the
terminal
connection
.
Failure
to
disconnect
the
motor
from
the
circuit
may
cause
damage
to
the
winding
insulation
.
7
.
Lubricate
the
silver
portion
of
the
ball
contact
at
the
top
of
the
breaker
bushing
and
the
rear
por
-
tion
of
the
ground
shoe
,
by
applying
a
thin
film
of
contact
lubricant
D
50
H
47
.
f
During
the
slow
closing
operation
check
to
insure
that
the
mechanism
does
not
stick
or
bind
during
the
entire
stroke
,
that
it
latches
securely
in
the
closed
position
,
and
that
it
trips
freely
when
the
manual
trip
lever
is
operated
.
At
this
time
,
also
check
the
following
adjustments
:
a
.
Arcing
contact
wipe
(
Refer
to
page
10
)
b
.
Primary
contact
wipe
(
Refer
to
page
10
)
c
.
Primary
contact
gap
(
Refer
to
page
11
)
i
DO
NOT
WORK
ON
EITHER
THE
BREAKER
OR
MECHANISM
UNLESS
THE
CLOSING
SPRINGS
ARE
BLOCKED
AND
THE
OPENING
SPRINGS
HAVE
8
.
Refer
to
metal
-
clad
instruction
book
GEH
-
1802
for
instructions
on
inserting
the
breaker
into
the
metal
-
clad
unit
.
DESCRIPTION
OF
OPERATION
The
Magne
-
blast
Breaker
has
two
principal
components
;
the
breaker
element
and
the
operating
mechanism
:
The
breaker
element
is
three
similar
pole
units
,
each
of
which
includes
the
current
carrying
parts
,
main
and
arcing
contacts
,
interrupter
,
and
an
enclosing
barrier
system
that
provides
insulation
between
poles
,
or
phases
and
to
ground
.
The
primary
connections
to
the
associated
metal
-
clad
switchgear
are
made
through
the
ball
contacts
at
the
top
of
the
breaker
bushings
.
The
operating
mechanism
type
ML
-
13
is
of
the
stored
energy
type
designed
to
give
high
speed
closing
and
opening
.
The
mechanism
will
operate
:
I
<
4
Courtesy of NationalSwitchgear.com

Magne
-
Blast
Circuit
Breaker
GEK
-
7345
Figure
1
.
(
8040935
)
Spring
Blocking
Device
Charge
-
Discharge
Indicator
Driving
Pawl
Manual
Close
Button
Eccentric
Manual
Charging
Wrench
Spring
Blocking
Device
1
.
2
.
3
.
4
.
5
.
6
.
9
10
1
Figure
2
.
(
8040932
)
Left
Side
View
ML
-
13
Operating
Mechanism
2
3
Secondary
Coupler
Interlock
Switches
Auxiliary
Switch
Latch
Checking
Switch
Switch
Cam
Closing
Roller
Power
Switches
Closing
Latch
Closing Springs
Motor
1
.
2
.
4
3
.
4
.
5
5
.
6
6
.
7
.
8
.
9
.
10
.
Figure
3
.
(
8038805
)
Spring
Discharge
Linkage
1
.
Link
Adjusting
Bolt
Trip
Latch
Crank
Discharge
Crank
Adjusting
Clevis
Spring
Release
Crank
2
.
3
.
4
.
5
.
6
.
5
I
Courtesy of NationalSwitchgear.com

GEK
-
7345
Magne
Blast
Circuit
Breaker
will function
during
manual
,
as
well
as
during
electrical
operation
of
the
equipment
,
both
mechan
-
ical
and electrical
blocking
is
provided
.
If
for
any
reason
the
closing
springs
should
be
discharged
against
the
positive
interlock
the
mechanism
will
be
jammed
and
be
inoperable
.
The
mechanism
can
be
released
and
returned
to
the
reset
position
by pushing
in
on
the
trip
lever
(
8
)
Figure
5
.
It
may
require
more
than
normal
force
to
release
the
interlock
.
A
plunger
interlock
,
Figure
14
can
be
provided
when
required
to
operate
a
stationary
auxiliary
switch
and
/
or
a
rod
interlock
mounted
in
the
metal
-
clad
unit
.
When
the breaker
is
used
interchangeably
with
type
MS
-
13
solenoid
operated
breakers
in
M
-
36
metal
-
clad
units
,
fuses
are
mounted
on
the
breaker
for
protection
of
the
motor
and
closing
circuit
.
These breakers
are
identified
by
either
a
"
C
"
,
"
F
"
or
"
J
"
suffix
in
the
breaker
nomenclature
.
on
a
-
c
or
d
-
c
voltage
as
indicated
on
the
breaker
nameplate
.
Closing
and
opening
operations
are
controlled
either
electrically
from
the
metal
-
clad
unit and
remote
location
,
or
mechanically
by
the
manual
close
and
trip
levers
on
the
breaker
.
All
secondary
connections
from
the
breaker
to
the
metal
clad
unit
are
made
through
the
coupler
(
1
)
Figure
2
.
A
spring
release interlock
,
Figure
3
,
is
provided
to
discharge
both
the
closing
and
opening
springs
when
the
breaker
is
withdrawn
from
or
inserted
into
the
metal
-
clad
unit
.
A
positive
interlock
(
3
)
Figure
4
and
interlock
switches
(
2
)
Figure
2
,
are
provided
between
the
breaker and
metal
-
clad
unit
to
prevent
raising
or
lowering
of
the
breaker
in
the unit while
in
a
closed
position
and
to
prevent
a
closing
operation
when the breaker
is
not
in
either
the
fully
raised
or
lowered
position
.
To
insure
that
this
interlock
-
1
2
3
4
5
6
7
8
9
10
1 1
12
Figure
5
.
(
8040934
)
Front
View
ML
-
13
Operating
Mechanism
1
.
Auxiliary
Switch
2
.
Open
-
Close
Indicator
3
.
Trip
Coil
4
.
Prop
Springs
5
.
Operation
Counter
6
.
Trip
Latch
7
.
Charge
-
Discharge
Indicator
8
.
Manual
Trip
Lever
9
.
Manual
Close
Button
10
.
Motor
Figure
4
.
(
8038804
)
Right
Side
View
ML
-
13
Operating
Mechanism
1
.
Upper
Spring
Pin
2
.
Latching
Pawls
3
.
Positive
Interlock
Roller
4
.
Opening
Spring
5
.
Cam
Shaft
6
.
Ratchet
Wheel
7
.
Bearing
Block
8
.
Driving
Pawl
9
.
Lower
Spring
Pin
10
.
Driving
Pawl
Lever
11
.
Eccentric
12
.
Closing
Spring
I
6
Courtesy of NationalSwitchgear.com

•
n
Magne
-
Blast
Circuit
Breaker
GEK
-
7345
The
pawl
advances
the
ratchet
wheel
(
6
)
Figure
4
a
few
degrees
each
stroke
where
it
is
held
in
position
by
the
latching
pawls
(
2
)
.
When
the
ratchet
wheel
has
been
rotated
approximately
180
degrees
the
closing
springs
(
12
)
will
be
fully
compressed
.
As
the
ratchet
wheel
continues
to
rotate
,
the
spring
load
will
shift
over
center
and
attempt
to
discharge
.
After
a
few
degrees
of
rotation
,
the
closing
roller
(
6
)
Figure
2
,
will
engage
the
closing
latch
(
8
)
and
the
compressed
springs
will
be
held
by
the
latch
until
a
closing
operation
is
required
.
During
the
last
few
degrees
of
the
ratchet
wheel
rotation
the
power
switches
(
7
)
are
opened
and
the
driving
pawl
is
raised
from
the
ratchet
wheel
surface
.
This
allows
the
motor
and
driving
mechanism
to
coast
to
a
natural
stop
expending
all
residual
energy
.
In
cases
where
breakers
with
type
ML
-
13
mechanisms
must
match
and
line
up
with
breakers
having
type
ML
-
11
mechanisms
the
spring
charging
circuit
for
both
mechanisms
should
be
fused
with
Buss
Company
Fusetrons
as
follows
:
Cont
.
Volt
.
Fuse
Size
Cat
.
No
.
48
v
d
-
c
llOv
d
-
c
125
v
d
-
c
115
v
a
-
c
220
v
d
-
c
250
v
d
-
c
230
v
a
-
c
10
A
FRN
10
FRN
4
FRN
4
FRN
4
FRN
2.5
FRN
2.5
FRN
2.5
4
A
4
A
4
A
2.5
A
2.5
A
2.5
A
Spring
Charging
The
mechanism
has
a
high
speed
gear
motor
(
10
)
Figure
5
,
that
compresses
a
set
of
closing
springs
through
the
action
of
an
eccentric
,
ratchet
,
and
pawl
assembly
.
The
rotary
action
of
the
motor
is
converted
to
a
straight
stroke
through
the
eccentric
(
11
)
Figure
4
,
and
a
lever
that
carries
a
spring
loaded
driving
pawl
(
2
)
Figure
1
.
During
the
time
the
springs
are
being
com
-
pressed
a
relay
(
17
)
Figure
6
,
is
energized
to
hold
the
closing
circuit
open
.
The
relay
remains
energized
until
the
springs
are
fully
charged
and
the
control
switch
contacts
are
re
-
set
.
2
3
5
6
7
8
i
9
S
-
10
11
12
13
14
15
16
17
Figure
6
.
(
8040933
)
Control
Mechanism
1
.
Latch
Checking
Switch
2
.
Switch
Cam
3
.
Switch
Striker
4
.
Switch
Support
Bolts
5
.
Switch
Support
6
.
Closing
Latch
Roller
Power
Switches
Closing
Latch
Closing
Latch
Shaft
Latch
Adjusting
Screw
Closing
Coil
Bolts
Closing
Latch
Spring
13
.
Latch
Monitoring
Switch
Switch
Mounting
Bracket
Closing
Solenoid
Closing
Coil
Support
Control
Relay
7
.
14
.
8
.
15
.
9
.
16
.
10
.
17
.
11
.
12
.
7
Courtesy of NationalSwitchgear.com

GEK
-
7345
Magne
-
Blast
Circuit
Breaker
closing
operation
the
opening
springs
(
4
)
Figure
4
,
are
compressed
and
held
ready
for
an
opening
operation
with
the
trip
latch
(
17
)
Figure
7
bearing
against
the
trip
latch
roller
(
19
)
.
When
the
closing
operation
of
the
breaker
is
completed
and
the
closing
latch
is
fully
reset
,
the
contacts
of
the
latch
monitoring
switch
closes
to
permit
the
spring
charging
motor
to
be
energized
and
recharge
the
closing
springs
.
Opening
Operation
The
closing
springs
may
be
charged
manually
if
control
voltage
is
lost
.
A
5
/
8
"
ratchet
wrench
can
be
used
to
rotate
the
eccentric
in
a
counter
clock
-
wise
direction
until
the
indicator
reads
"
Charged
"
and
the
driving
pawl
is
raised
from
the
ratchet
wheel
.
The
use
of
the
ratchet
wrench
provides
for
maximum
safety
in
the
event
that
control
power
is
suddenly
restored
without
warning
.
In
this
event
,
the
motor
drive
will
override
the
ratchet
wrench
and
continues
to
charge
the
springs
.
Closing
Operation
The
breaker
can
be
closed
electrically
by
energizing
the
closing
solenoid
(
15
)
Figure
6
,
or
manually
by
pushing
the
close
button
(
9
)
Figure
5
.
In
either
method
the
closing
latch
is
rotated
from
under
the
closing
roller
to
release
the
closing
springs
(
9
)
Figure
2
.
The
energy
in
the
springs
is
used
to
rotate
a
cam
(
8
)
Figure
7
,
and
close
the
breaker
through
the
operating
mechanism
linkage
.
During
the
closing
operation
,
the
mech
-
anism
is
trip
-
free
at
all
times
.
The
breaker
is
held
closed
by
the
closing
prop
(
5
)
moving
into
position
under
the
prop
pin
(
4
)
.
During
the
i
The
breaker
can
be
opened
either
electrically
by
energizing
the
trip
coil
(
3
)
Figure
5
,
or
manually
by
pushing
the
trip
lever
(
8
)
.
In
each
method
the
trip
latch
is
rotated
off
the
trip
latch
roller
,
permitting
the
operating
mechanism
linkage
to
collapse
.
The
energy
stored
in
the
opening
springs
is
released
to
provide
the
required
opening
speed
for
successful
interruption
of
the
circuit
.
As
the
breaker
opens
to
interrupt
a
current
,
the
arc
first
starts
at
the
arcing
contacts
(
5
&
21
)
Figure
8
,
transfers
to
the
arc
runner
(
3
&
8
)
and
S
9
10
II
21
22
2
3
23
4
4
15
16
17
5
24
18
6
25
19
26
20
8
Figure
7
.
(
0134
C
3583
)
Sectional
Side
View
of
Mechanism
1
.
Main
Shaft
Bearing
Crank
Shaft
Cranks
Prop
Pin
Prop
Cam
Shaft
Cam
Shaft
Bearing
Cam
Handle
10
.
Trip
Coil
Support
11
.
Trip
Coil
12
.
Upper
Prop
Spring
13
.
Trip
Armature
Lower
Prop
Spring
15
.
Cam
Follower
Roller
16
.
Trip
Shaft
17
.
Trip
Latch
18
.
Stop
Pin
19
.
Trip
Latch
Roller
20
.
Trip
Latch
Roller
Support
21
.
Check
Nut
22
.
Stop
Plate
23
.
Spring
Rod
24
.
Spring
25
.
Spring
26
.
Spring
Guide
2
.
3
.
4
.
t
5
.
14
.
6
.
7
.
8
.
9
.
Courtesy of NationalSwitchgear.com

Magne
-
Blast
Circuit
Breaker
GEK
-
7345
energizes
the
blow
-
out
coils
(
2
&
7
)
.
This action
introduces
a
magnetic
field between
the
pole
pieces
(
4
&
9
)
of
the
interrupter
that
forces
the
arc
deeper
into
the
arc
chute
(
6
)
.
At
the time
the
arcing
contacts
part
a
discharge
of
air
is
expelled
through
the booster
tube
(
22
)
across
the
arc
.
interruption
by
blowing
the
arc
away
from
the
contacts
and
into the
arc
chute
.
As
the
magnetic
field
forces
the
arc
deeper
into
the
interrupter
along
the
diverging
arc
runners
,
the
field
is
progressively
increased
by
the insertion
of
each
additional
blow
-
out
coil
into
the circuit
.
deepening
serpentine path
between the
fins
so
that
the electrical
resistance
of
the
arc
is
rapidly
increased and its heat
is
absorbed
by
the ceramic
material
.
The
increased
resistance reduces
the
magnitude
and
phase
angle
of
the
current
and
at
an
early
current
zero
the
arc
cannot
re
-
establish
itself
and
interruption
occurs
.
Trip
Free
Operation
*
This
air
flow assists the
arc
transfer
and
If
the
trip
coil circuit is
energized
while the
breaker
is
closing
,
the
trip
armature
will
force
the
trip
latch
(
17
)
Figure
7
away
from
the
trip
roller
(
19
)
causing
the
mechanism
linkage
to
collapse
and
the
breaker
to
re
-
open
.
The
closing
cam
(
8
)
will
complete
its
closing
stroke and the
springs
will
re
-
charge
as
in
a
normal
closing
operation
.
The
arc
chute has
a
series
of
interleaving
ceramic
fins
,
Figure
19
.
As
the
arc
is
forced
into
the
interrupter
it
is
lengthened
in
the
gradually
10
II
12
f
13
2
14
“
2
o
15
l
16
>
4
51
;
17
18
O
5
Li
19
6
lrf
\
rv
20
7
3
8
21
iT
i
22
i
!
|
9
icy
1
tip
"
7
M
!
j
23
1
l
\
\
\
“
V
*
S
!
24
1
i
I
Figure
8
.
(
015205904
)
Cross
Section
of
Breaker
Pole
Unit
17
.
Stationary
Primary
Contact
18
.
Movable
Primary
Contact
19
.
Hinge
Cup
Bearing
Upper
Horizontal
Barrier
20
.
Contact
Arm
Assembly
21
.
Movable
Arcing
Contact
22
.
Booster
Tube
and
Piston
Lower
Horizontal
Barrier
23
.
Connection
Bar
24
.
Booster
Cylinder
Lower
Pole
Pieces
Front
Bushing
Rear
Bushing
1
.
9
.
Box
Barrier
Upper
Blow
-
Out
Coil
Upper
Arc
Runner
Upper
Pole Pieces
Stationary
Arcing
Contact
Arc
Chute
Side
Lower
Blow
-
Out
Coil
Lower
Arc
Runner
10
.
2
.
11
.
3
.
12
.
4
.
13
.
Main
Operating
Crank
Spring
Retainer
5
.
14
.
6
.
15
.
7
.
16
.
Operating
Rod
8
.
9
Courtesy of NationalSwitchgear.com

GEK
-
7345
Magne
-
Blast
Circuit
Breaker
ADJUSTMENTS
the
movable
primary
contact
(
2
)
should
be
5
/
16
”
or
greater
.
This
setting
has
been
made
in
the
factory
and
no
adjustment
is
provided
.
A
wipe
of
less
than
5
/
16
"
is
an
indication
that
the
arcing
contacts
need
to
be
replaced
.
When
making
this
check
,
see
that
there
is
clearance
between
the
arcing
contact
(
5
)
and
the
slot
in
the
throat
baffle
(
7
)
during
entire
stroke
of
the
moving
contact
assembly
.
Primary
Contact
Wipe
All
adjustments
should
be
checked
during
periodic
inspections
and
whenever
it
becomes
necessary
to
repair
or
replace
parts
that
have
become
worn
or
defective
while
in
service
.
The
following
adjustments
are
listed
in
the
order
in
which
they
are
to
be
checked
after
removing
the
box
barriers
and
front
cover
from
the
breaker
.
DO
NOT
WORK
ON
EITHER
THE
BREAKER
OR
MECHANISM
UNLESS
THE
CLOSING
SPRINGS
ARE
BLOCKED
AND
THE
OPENING
SPRINGS
HAVE
BEEN
TRIPPED
OPEN
OR
MECHANICALLY
BLOCKED
.
PREVENT
ACCIDENTAL
CLOSING
OR
TRIPPING
.
Refer
to
Figure
9
,
when
the
breaker
is
closed
the
stationary
primary
contacts
(
1
)
should
rise
from
1
/
4
"
to
5
/
l
6
"
.
Before
checking
this
dimen
-
sion
be
sure
the
mechanism
is
re
-
set
so
that
the
prop
pin
(
4
)
Figure
7
is
resting
on
the
prop
.
To
obtain
the
proper
contact
adjustment
,
open
the
breaker
,
and
,
referring
to
Figure
10
,
loosen
the
check
nut
(
4
)
and
turn
the
adjusting
nut
(
3
)
.
Screwing
up
on
the
adjusting
nut
will
decrease
the
primary
contact
wipe
,
down
will
increase
it
.
Tighten
the
check
nut
,
close
the
breaker
and
THIS
MEASURE
IS
REQUIRED
TO
f
Arcing
Contact
Wipe
Refer
to
Figure
9
.
Close
the
breaker
until
the
arcing
contacts
just
touch
.
This
can
be
determined
with
the
use
of
a
circuit
continuity
tester
such
as
a
light
indicator
or
bell
set
.
In
this
position
,
the
gap
between
the
stationary
primary
contacts
(
1
)
and
5
!
?
1
a
3
3
4
4
#
>
<
b
5
3
7
7
i
Primary
Contact
Wipe
Arcing
Contact
Wipe
Figure
9
.
(
0132
C
2778
)
Contact
Adjustments
1
.
Stationary
Primary
Contacts
Movable
Primary
Contacts
Buffer
Block
Stationary
Arcing
Contacts
5
.
Movable
Arcing
Contacts
6
.
Contact
Arm
7
.
Throat
Baffle
2
.
3
.
4
.
10
Courtesy of NationalSwitchgear.com