GE GEK-7345 User manual

INSTRUCTIONS
AND
RECOMMENDED
PARTS
FOR
MAINTENANCE
GEK
-
7345
A
Supersedes
GEK
-
7345
{
!
MAGNE
-
BLAST
CIRCUIT
BREAKER
I
J
TYPE
AM
-
13.8
-
750
-
5
1200
&
2000
AMPERE
W
/
ML
-
13
MECHANISM
I
:
:
INTRODUCTION
.
.
•
3
•
• •
• •
•••
•
I
RECEIVING
,
HANDLING
AND
STORAGE
.
1
!
#
•
«
3
•
• •
• •
•
• •
INSTALLATION
.
.••
•
•
A
••
• •
•
•
DESCRIPTION
OF
OPERATION
.
.
*
*
*
4
•
•
•
• • •
•
•
•
•
1
ADJUSTMENTS
10
I
!
GENERAL
MAINTENANCE
15
it
SI
W
28
RENEWAL
PARTS
I
1
1
s
II
I
I
SWITCHGEAR PRODUCTS
DEPARTMENT
ELECTRIC
GENERAL
I
PHILADELPHIA
,
PA
.
ZJZIZ
:
.
Courtesy of NationalSwitchgear.com

Trnr
-
Tr
—
-
1
“
I
;
I
!
:
:
'
i
i
i
Courtesy of NationalSwitchgear.com

MAGNE
-
BLAST
CIRCUIT
BREAKER
AM
-
13.8
-
750
-
5
Letter
designation
B
,
C
,
F
,
H
,
J
,
L
,
N
,
&
P
used
immediately
following
the
model
number
indicates
basic
design
features
.
INTRODUCTION
The
Magne
-
blast
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
,
IEEE
and
NEMA
standards
;
but
no
such
assurance
is
given
with
respect
to
local
codes
and
ordinances
because
they
vary
greatly
.
Should
3
A
.
:
..
:
V
j
.
..
i
IVv
.
V
.
V
.
.
Courtesy of NationalSwitchgear.com

GEK
-
7345
Magne
-
Blast
Circuit
Breaker
i
INSTALLATION
ER
OR
MECHANISM
UNLESS
THE
CLOS
-
ING
SPRINGS
ARE
BLOCKED
AND
THE
OPENING
SPRINGS
HAVE
BEEN
TRIP
-
PED
OPEN
OR
MECHANICALLY
BLOCK
-
ED
.
THIS
PRECAUTION
IS
REQUIRED
TO
PREVENT
ACCIDENTAL
CLOSING
OR
TRIPPING
.
1
.
Remove
the
box
barrier
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
18
and
Figure
17
.
2
.
Charge
the
breaker
closing
springs
man
-
ually
using
a
5
/
8
"
ratchet
wrench
to
turn
the
driving
eccentric
(
4
)
Figure
1
.
Turning
the
eccentric
counter
clockwise
will
ad
-
vance
the
ratchet
wheel
and
compress
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
.
Insert
the
spring
blocking
device
(
6
)
and
manually
discharge
the
springs
against
the
pins
by
pushing
the
manual
close
.
button
(
3
)
.
The
springs
are
now
blocked
and
slow
closing
of
the
breaker
contacts
can
be
accomplished
by
again
turning
the
driving
eccentric
with
a
5
/
8
"
ratchet
wrench
.
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
pagelO
)
c
.
Primary
contact
gap
(
Refer
to
page
11
)
.
;
v
~
The
closing
springs
should
now
be
un
-
blocked
.
Rotate
the
driving
eccentric
until
the
indicator
reads
"
CHARGED
"
and
the
ratchet
wheel
does
not
advance
.
The
spring
blocking
device
can
now
be
removed
.
Connect
the
test
coupler
to
the
circuit
breaker
and
operate
it
electrically
sev
-
eral
times
.
Check
the
control
voltage
as
described
under
"
CONTROL
POWER
CHECK
"
(
Page
14
)
.
Disconnect
the
test
coupler
and
replace
box
barrier
.
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
)
.
I
3
.
4
.
5
.
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
dis
-
connect
the
motor
from
the
circuit
may
cause
damage
to
the
winding
insulation
.
Lubricate
the
silver
portion
of
the
ball
contact
at
the
top
of
the
breaker
bushing
by
applying
,
a
thin
film
of
contact
lu
-
bricant
D
50
H
47
Refer
to
metal
-
clad
instruction
book
GEH
-
1802
for
instruction
on
inserting
the
breaker
into
the
metal
-
clad
unit
.
6
.
7
.
DO
NOT
WORK
ON
EITHER
THE
BREAK
-
DESCRIPTION
OF
OPERATION
stored
energy
type
designed
to
give
high
speed
closing
and
opening
.
The
mechanism
will
operate
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
.
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
I
4
§
:
Courtesy of NationalSwitchgear.com

Magne
-
Blast
Circuit
Breaker
GEK
-
7345
Figure
1
.
(
8040935
)
Spring
Blocking
Device
1
.
Charge
-
Discharge
Indicator
Driving
Pawl
Manual
Close
Button
Eccentric
Manual
Charging
Wrench
Spring
Blocking
Device
Figure
2
.
(
8040932
)
Left
Side
View
ML
-
13
Operating
Mechanism
2
3
i
.
Secondary
Coupler
Interlock
Switches
Auxiliary
Switch
Latch
Checking
Switch
Switch
Cam
Closing
Roller
Power
Switches
Closing
Latch
Closing
Springs
Motor
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
V
'
TWiTV
'
" '
Courtesy of NationalSwitchgear.com

GEK
-
7345
Magne
Blast
Circuit
Breaker
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
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
.
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
:
Cat
.
No
.
Cont
.
Volt
.
Fuse
Size
FRN
10
FRN
4
FRN
4
FRN
4
FRN
2.5
FRN
2.5
FRN
2.5
48
v
d
-
c
HOv
d
-
c
125
v
d
-
c
115
v
a
-
c
220
v
d
-
c
250
v
d
-
c
230
v
a
-
c
10
A
4
A
4
A
4
A
2.5
A
2.5
A
2.5
A
•
’
4
ff
I
iitic
fails
1
MSHS
12
b
2
mg
PriMa
*
A
'
3
n
at
-
4
Ilia
5
tmm
6
ipLh
•
•
V
7
'
8
9
*
s
»
Sska
)
Sis
'
10
1
—
Figure
4
.
(
8038804
)
Right
Side
View
ML
-
13
Operating
Mechanism
Figure
5
.
(
8040934
)
Front
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
1
.
Auxiliary
Switch
Open
-
Close
Indicator
Trip
Coil
Prop
Springs
Operation
Counter
Trip
Latch
Charge
-
Discharge
Indicator
Manual
Trip
Lever
Manual
Close
Button
Motor
2
.
3
.
4
.
5
.
6
.
7
.
8
.
9
.
10
.
6
Courtesy of NationalSwitchgear.com

Magne
-
Blast
Circuit
Breaker
GEK
-
7345
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
.
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
.
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
.
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
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
.
1
2
3
4
5
6
8
I
_
9
S
.
IQ
11
12
13
14
wm
16
17
Figure
6
.
(
8040933
)
Control
Mechanism
Latch
Monitoring
Switch
Switch
Mounting
Bracket
Closing
Solenoid
Closing
Coil
Support
Control
Relay
13
.
Power
Switches
Closing
Latch
Closing
Latch
Shaft
15
.
Latch
Adjusting
Screw
16
.
Closing
Coil
Bolts
Closing
Latch
Spring
1
.
Latch
Checking
Switch
Switch
Cam
Switch
Striker
Switch
Support
Bolts
Switch
Support
Closing
Latch
Roller
7
.
14
.
2
.
8
.
3
.
9
.
4
.
10
.
17
.
5
.
11
.
6
.
12
.
7
Courtesy of NationalSwitchgear.com

GEK
-
7345
Magne
-
Blast
Circuit
Breaker
Closing
Operation
Opening
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
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
.
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
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
.
This
air
flow
assists
the
arc
transfer
and
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
!
9
10
+
<
>
v
v
.
.
I
/
II
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/
/
/
i
2
iirhii
21
i
.
3
22
2
/
'
/
Jx
-
\
s
3
23
J
1
A
-
mt
-
_
J
4
/
<
4
15
a
16
m
\
17
/
5
24
SI
18
25
6
19
26
\
\
\
/
j
v
\
\
i
I
'
i
I
'
A
/
20
cr
.
i
8
*
\
I
•
t
t
^
—
J
/
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'
/
;
/
i
^
#
=
¥
rf
£
l
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
Trip
Coil
Upper
Prop
Spring
Trip
Armature
Lower
Prop
Spring
Cam
Follower
Roller
Trip
Shaft
Trip
Latch
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
.
11
.
3
.
12
.
4
.
13
.
5
.
14
.
6
.
15
.
7
.
16
.
8
.
17
.
9
.
i
18
.
.
I
8
s
Courtesy of NationalSwitchgear.com

1
Magne
-
Blast
Circuit
Breaker
GEK
-
7345
along
the
diverging
arc
runners
,
the
field is
progressively
increased
by
the insertion
of
each
additional blow
-
out
coil
into
the circuit
.
an
early
current
zero
the
arc
cannot
re
-
establish
itself
and
interruption
occurs
.
Trip
Free
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
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
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
.
£
2
10
II
12
13
2
O
14
3
15
1
i
16
4
17
5
18
6
19
7
20
8
21
22
9
23
*
24
1
“
I
1
y
Figure
8
.
(
0152
C
5904
)
Cross
Section
of
Breaker
Pole
Unit
17
.
Stationary
Primary
Contact
18
.
Movable
Primary
Contact
19
.
Hinge
Cup
Bearing
1
.
Lower
Pole
Pieces
Front
Bushing
Rear
Bushing
Upper
Horizontal
Barrier
2
Q
.
Contact
Arm
Assembly
Main
Operating
Crank
Spring
Retainer
Lower
Horizontal
Barrier
23
.
Connection
Bar
Operating
Rod
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
9
.
2
.
10
.
3
.
11
.
12
.
4
.
13
a
21
.
Movable
Arcing
Contact
22
.
Booster
Tube
and
Piston
5
.
6
.
14
.
7
.
15
.
24
.
Booster
Cylinder
8
.
16
.
9
i
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
Arcing
Contact
Wipe
Refer
to
Figure
9
.
Close
the
breakeruntil
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
D
5
*
1
«
.
?
2
3
3
4
4
<
o
5
5
7
7
Primary
Contact
Wipe
Arcing
Contact
Wipe
Figure
9
.
(
0132
C
2778
)
Contact
Adjustments
i
.
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