GE AM-4.16-250-9 User manual

INSTRUCTIONS
AND
RECOMMENDED
PARTS
GEK
-
41902
FOR
MAINTENANCE
28
I
I
I
I
©
SWITCHGEAR
PRODUCTS
DEPARTMENT
«
GENERAL
ELECTRIC
5
t
I
!
1
1
PHILADELPHIA
,
PA
.
1
a
Courtesy of NationalSwitchgear.com

Courtesy of NationalSwitchgear.com

MAGNE
-
BLAST
CIRCUIT
BREAKER
AM
-
4.16
-
250
-
9
(
z
\
)
Letter
Designation
B
,
C
,
H
,
K
,
R
and
N
,
used
immediately
following
the
model
number
indicates
basic
design
features
.
INTRODUCTION
voltage
,
current
,
and
interrupting
ratings
are
never
exceeded
.
all
ratings
of
the
breaker
as
well
as
several
design
variations
,
the
instructions
will
be
of
a
general
character
and
all
illustrations
will
be
typical
unless
otherwise
specified
.
The
Magne
-
blast
breaker
is
the
removable
and
interchangeable
interrupting
element
used
in
metal
-
clad
switchgear
to
provide
reliable
control
and
pro
-
tection
of
electrical
apparatus
and
power
systems
.
The
AM
-
4.16
-
250
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
describes
the
control
power
requirements
for
that
breaker
.
The
application
of
a
breaker
must
be
such
that
its
voltage
,
current
,
Since
this
book
is
written
to
include
PROPER
INSTALLATION
AND
MAINTENANCE
ARE
NECESSARY
TO
INSURE
CONTINUED
SAT
-
ISFACTORY
OPERATION
OF
THE
BREAKER
.
The
following
instructions
will
provide
complete
infor
-
mation
for
placing
magne
-
blast
breakers
in
service
and
for
maintaining
satisfactory
operation
.
RECEIVING
,
HANDLING
AND
STORAGE
Receiving
and
Handling
against
condensation
,
preferable
by
stor
-
ing
it
in
a
warm
dry
room
,
since
water
absorption
has
an
adverse
effect
on
the
insulation
parts
,
outdoor
metal
-
clad
switchgear
should
be
stored
in
the
equipment
only
when
power
is
available
and
the
heaters
are
in
operation
to
prevent
condensation
.
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
com
-
pany
and
the
nearest
General
Electric
Sales
Office
should
be
notified
.
Circuit
breakers
for
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
.
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
.
<
M
co
o
oo
3
.
Unfinished
surfaces
of
rollers
,
latches
etc
.
,
of
the
operating
mechanism
should
be
coated
with
grease
to
prevent
rusting
.
O
HM
o
Storage
PM
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
:
If
the
breaker
is
stored
for
any
length
of
time
,
it
should
be
inspected
periodically
to
see
that
rust
-
ing
has
not
started
and
to
insure
good
mechanical
condition
Should
the
breaker
be
stored
under
unfavorable
atmospheric
conditions
,
it
should
be
cleaned
and
dried
out
before
being
placed
in
service
.
1
.
The
breaker
should
be
carefully
protected
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
end
ordinances
because
they
vary
greatly
.
Should
3
Courtesy of NationalSwitchgear.com

GEK
-
41902
Magne
-
blast
Circuit
Breaker
INSTALLATION
1
.
Remove
the
box barrier and mechanism
cover
and
make
a
visual
inspection
to
as
-
certain
that
the
breaker
and
mechanism is
in
satisfactory
condition
.
Check
all
bearing
surfaces
of
the
mechanism
for
lubrication
.
Refer
to
section
on
lubrication
page
16
and
Figure
17
.
2
.
Charge
the
breaker
closing
springs
man
-
ually
using
a
5
/
8
"
ratchet wrench
to turn
the
driving
eccentric
(
6
)
Figure
1
.
Turning
the
eccentric
counter
clockwise
will
advance
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
.
Ad
-
ditional
turning
of
the
eccentric
will
not
advance the ratchet wheel
.
OR
MECHANISM
UNLESS
THE
CLOSING
SPRINGS
ARE
BLOCKED
AND
THE
OPEN
-
ING
SPRINGS
HAVE
BEEN
TRIPPED
OPEN
OR
MECHANICALLY
BLOCKED
.
THIS
PRECAUTION
IS
REQUIRED
TO
PREVENT
ACCIDENTAL
CLOSING
OR TRIPPING
.
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
.
w
:
a
3
.
Connect
the
test
coupler
to
the
circuit
breaker and
operate
it
electrically
several
times
.
Check
the
control
voltage
as
de
-
scribed under
"
CONTROL
POWER CHECK
"
(
Page
14
)
.
Disconnect
the
test
coupler
and
replace
box
barrier
.
4
.
Insert
the
spring
blocking
device
(
10
)
and
manually discharge
the
springs against
the
pins
by pushing
the
manual release button
(
4
)
.
The
springs
are
now
blocked and
slow
closing
of
the
breaker
contacts
can
be
acco
ecce
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
.
Insulation
Test
(
Page
16
)
.
5
.
Refer
to
mplished
by
again turning
the
driving
ntric
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
(
Refertopage
11
)
c
.
Primary
contact
gap
(
Refer
to
page
11
)
If
the breaker
secondary
wiring
NOTE
:
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
.
6
.
Lubricate
the silver
portion
of
the
ball
contact
at
the
top
of
the
breaker
bushing
and
the
rear
portion
of
the
ground
shoe
,
by
apply
-
ing
a
thin
film
of
contact
lubricant
D
50
H
47
.
Refer
to
metal
-
clad
instruction
book
GEH
-
1802
for
instructions
on
inserting
the
break
-
er
into
the metal
-
clad
unit
.
7
.
DO
NOT
WORK
ON
EITHER THE
BREAKER
DESCRIPTION
OF
OPERATION
The
Magne
-
blast
B
reaker
has
two
principal
com
-
ponents
;
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
pri
-
mary
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
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
)
Fig
.
2
.
A
spring
release
interlock
,
Fig
3
,
is
provided
to
discharge
both
the
closing
and
opening
springs
when
the
breaker
is
withdrawn
from
or
inserted
into
the
Metal
Clad
unit
.
4
Courtesy of NationalSwitchgear.com

T
Magne
-
blast
Circuit
Breaker
GEK
-
41902
1
2
:
:
3
4
-
5
6
8
9
10
Figure
1
.
(
8034475
)
Spring
Blocking
Device
•
1
;
U
1
.
Charge
-
Discharge
Indicator
2
.
Support
Bolts
3
.
Driving
Pawl
4
.
Manual
Close
Lever
5
.
Motor
6
e
Eccentric
7
.
Closing
Spring
Manual
Charging
Wrench
Fuse
Spring
Blocking
Device
Figure
2
.
(
8034473
)
Left
Side View
ML
-
13
Operating
Mechanism
1
i
.
Secondary
Coupler
Interlock
Switches
Auxiliary
Switch
Latch
Checking
Switch
Switch
Cam
Charge
-
Discharge
Indicator
Closing
Latch
Roller
Power
Switches
Closing
Latch
Closing
Springs
Motor
Fuses
2
2
.
3
«
4
.
5
.
6
.
7
.
8
.
9
.
10
.
ii
;
12
.
Figure
3
.
(
8038805
)
Spring
Discharge
Linkage
1
.
Link
2
.
Adjusting
Bolt
3
.
Trip
Latch
Crank
4
.
Discharge
Crank
5
.
Adjusting
Clevis
6
.
Spring
Release
Crank
5
Courtesy of NationalSwitchgear.com

~
"
“
T
GEK
-
41902
Magne
-
blast
Circuit
Breaker
A
positive
interlock
(
3
)
Figure
4
and interlock
switch
(
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
dis
-
charged against
the
positive
interlock
the mechan
-
ism
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
.
When
the
breaker
is used
interchangeably
with
type
MS
-
13
solenoid
operated
breakers
in
M
-
26
metal
-
clad units
,
fuses
(
12
)
Figure
2
,
are
mounted
on
the
breaker
for
protection
of
the
motor
and
closing
circuit
.
These
breakers
are
identified
by
a
"
C
”
or
"
K
"
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
:
Cont
.
Volt
.
Cat
.
No
.
Fuse
Size
t
,
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
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
.
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
eccen
-
tric
(
11
)
Figure
4
,
and
a
lever
that
carries
a
spring
loaded
driving
pawl
(
3
)
Figure
1
.
2
3
5
6
9
fH
10
yf
/
Figure
4
.
(
8034463
)
Right
Side
View
<
-
ML
-
13
Operating
Mechanism
Figure
5
.
(
8034471
)
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
2
.
Open
-
Close
Indicator
3
.
Trip
Coil
4
.
Prop
Spring
5
.
Operation
Counter
6
.
Trip
Latch
7
.
Charge
-
Discharge
Indicator
8
.
Manual
Trip
Lever
9
.
Manual
Close
Lever
10
.
Motor
6
Courtesy of NationalSwitchgear.com

1
Magne
-
blast
Circuit
Breaker
GEK
-
41902
The
pawl
advances
the
ratchet
wheel
(
6
)
Figure
4
a
few
degrees
each
stroke
where
it
is
held
in
pos
-
ition
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
(
7
)
Figure
2
,
will
engage
the
closing
latch
(
9
)
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
(
8
)
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
.
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
clockwise
direction
until
the
indicator
reads
"
Charg
-
ed
"
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
spring
release
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
(
10
)
Figure
2
.
The
energy
in
the
springs
is
used
to
rotate
a
cam
(
16
)
Figure
7
and
close
the
breaker
through
the
operating
mechanism
linkage
.
During
the
closing
operation
the
mechanism
is
trip
-
free
at
all
times
.
The
break
-
er
is
held
closed
by
the
closing
prop
(
14
)
moving
into
position
under
the
prop
pin
(
13
)
.
During
the
closing
operation
the
opening
springs
(
4
)
Figure
4
,
are
compressed
and
held
ready
for
an
opening
operation
with
the
trip
latch
(
8
)
Figure
7
bearing
against
the
trip
latch
roller
(
9
)
.
When
the
closing
operation
of
the
breaker
is
completed
and
the
closing
latch
is
fully
reset
,
I
J
10
11
12
13
14
«
9
lit
15
16
17
Figure
6
.
(
8034467
)
Control
Mechanism
13
.
Latch
Monitoring
Switch
14
.
Switch
Mounting
Bracket
15
.
Spring
Release
Solenoid
16
.
Release
Coil
Support
17
.
Control
Relay
7
.
Power
Switches
8
.
Closing
Latch
9
.
Closing
Latch
Shaft
10
.
Latch
Adjusting
Screw
11
.
Release
Coil
Bolts
12
.
Closing
Latch
Spring
1
.
Latch
Checking
Switch
2
.
Switch
Cam
3
.
Switch
Striker
4
.
Switch
Support
Bolts
5
.
Switch
Support
6
.
Closing
Latch
Roller
7
Courtesy of NationalSwitchgear.com

H
!
GEK
-
41902
Magne
-
blast
Circuit
Breaker
:
i
I
;
the
contacts
of
the
latch
monitoring
switch
closes
to
permit
the
spring
charging
motor
to
be
energiz
-
ed
and
recharge
the
closing
springs
.
Opening
Operation
The
breaker
can
be
opened
either
electrically
by
energizing
the
trip
coil
(
3
)
Figure
5
,
or
man
-
ually
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
(
6
&
27
)
Figure
8
,
transfers
to
the
arc
runner
(
4
&
10
)
and
energizes
the
blow
-
out
coils
(
3
&
11
)
.
This
action
introduces
a
magnetic
field
between
the
pole
pieces
(
5
&
9
)
of
the
interrupter
that
forces
the
arc
deeper
into
the
arc
chute
(
8
)
.
the
arcing
contacts
part
a
discharge
of
air
is
expelled
through
the
booster
tube
(
28
)
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
.
The
magnetic
field
forces
the
arc
deeper
into
thq
interrupter
along
the
diverging
arc
runners
.
i
I
:
At
the
time
;
Fig
.
7
(
0114
C
5320
)
Sectional
Side
View
of
Mechanism
18
.
Stop
Plate
19
.
Spring
Rod
20
.
Spring
21
.
Spring
22
.
Spring
Guide
23
.
Stop
Pin
24
.
Main
Shaft
Bearing
25
.
Cam
Shaft
Bearing
10
.
Trip
Latch
Roller
Support
11
.
Crank
Shaft
12
.
Cranks
13
.
Prop
Pin
14
.
Prop
15
.
Drive
Shaft
16
.
Cam
.
17
.
Check
Nut
1
.
Handle
Trip
Coil
Support
Trip
Coil
Trip
Armature
Prop
Reset
Spring
Cam
Follower
Roller
Trip
Shaft
Trip
Latch
Trip
Latch
Roller
2
.
3
.
4
.
5
.
6
.
I
7
.
8
.
9
,
8
Courtesy of NationalSwitchgear.com

I
Magne
-
blast
Circuit
Breaker
GEK
-
41902
14
15
16
17
i
I
N
'
2
S
3
18
19
4
20
r
y
*
5
21
.
s
6
Hi
22
:
23
4
4
8
\
24
S
25
9
26
10
4
VT
27
t
—
H
\
I
x
\
'
I
i
£
i
ii
28
t
l
£
ct
29
12
/
47
30
TO
'
>
7
13
W
df
TO
Ud
:
Figure
8
.
(
0152
C
5973
)
Cross
Section
of
Breaker
Pole
Unit
11
.
Lower
Blow
-
out
Coil
21
.
Operating
Rod
12
.
Lower
Blow
-
out
Core
22
.
Stationary
Primary
Contacts
13
.
Box
Barrier
Guide
23
.
Movable
Primary
Contacts
14
.
Front
Bushing
24
.
Cup
Bearing
15
.
Rear
Bushing
25
.
Yoke
16
.
Frame
26
.
Movable
Contact
Arm
Assembly
17
.
Main
Operating
Crank
27
.
Movable
Arcing
Contact
18
.
Primary
Contact
Springs
28
.
Booster
Tube
and
Piston
19
.
Spring
Retainer
29
.
Connection
Bar
20
.
Lower
Horizontal
Barrier
30
.
Booster
Cylinder
Box
Barrier
Support
Upper
Blow
-
out
Core
Upper
Blow
-
out
Coil
Upper
Arc
Runner
Upper
Pole
Piece
Stationary
Arcing
Contact
Box
Barrier
Arc
Chute
Side
Lower
Pole
Piece
Lower
Arc
Runner
1
.
2
.
3
.
4
.
5
.
6
.
7
.
8
.
9
.
10
.
9
Courtesy of NationalSwitchgear.com

GEK
-
41902
Magne
-
blast
Circuit
Breaker
The
arc
chute has
a
series
of
interleaving
cer
-
amic
fins
,
Figure
19
.
As
the
arc
is
forced into
the
interrupter
it
is
lengthened
in
the
gradually
deep
-
ening
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
If
the
trip
coil circuit
is
energized
while
the
breaker
is
closing
,
the
trip
armature
will
force
the
trip
latch
(
8
)
Figure
7
away
from
the
trip
roller
(
9
)
causing
the
mechanism
linkage
to
colla
;
and
the breaker
to
re
-
open
.
The
closing
cam
will
complete
its
closing
stroke
and
the
springs
will
re
-
charge
as
in
a
normal
closing
operation
.
pse
(
16
)
ADJUSTMENTS
All
adjustments
should
be
checked
during
per
-
iodic
inspections
and
whenever
it
becomes
nec
-
essary
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
.
MECHANISM
UNLESS
THE
CLOSING SPRINGS
ARE
BLOCKED
AND
THE
OPENING
SPRINGS
HAVE
BEEN
TRIPPED
OPEN
OR
MECHANICALLY
BLOCKED
.
THIS
MEASURE
IS
REQUIRED
TO
PREVENT
ACCIDENTAL CLOSING OR
TRIPPING
.
Arcing
Contact
Wipe
DO NOT WORK ON
EITHER THE
BREAKER
OR
Refer
to
Figure
9
.
Close
the breaker
until
ID
r
-
qD
m
i
t
re
i
f
0
.
1
r
~
i
I
|
i
i
I
I
5
A
\
u
i
'
-
ll
i
3
I
pi
^
\
+
A
©
:
A
\
±
4
\
\
V
\
4
4
,
\
A
\
\
W
>
6
I
—
\ \
3
5
7
7
Arcing
Contact
Wipe
Primary
Contact
Wipe
Figure
9
.
"
-
9
"
Contact Structure
(
0132
C
2709
)
Figure
9
Contact
Adjustments
if
-
1
.
Stationary
Primary
Contacts
5
.
Movable
Arcing
Contacts
2
.
Movable
Primary
Contacts
6
.
Contact
Arm
7
.
Throat
Baffle
3
.
Buffer
Block
4
.
Stationary
Arcing
Contacts
10
i
t
Courtesy of NationalSwitchgear.com

T
iviagne
-
blast
Circuit
Breaker
GEK
-
41902
the
arcing
contacts
just
touch
,
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
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
the
movable
arcing
contact
(
5
)
passes
between
the
probes
on
the
upper
arc
runner
without
touching
.
On
the
"
-
9
"
design
,
check
for
clearance
between
the
arcing
contact
(
5
)
and
the
slot
in
the
throat
baffle
(
7
)
during
entire
stroke
of
the
moving
contact
assembly
.
This
can
be
Primary
Contact
Gap
Refer
to
Figure
10
.
With
the
breaker
closed
,
press
the
manual
trip
button
allowing
the
breaker
to
trip
open
normally
.
Do
not
force
the
contacts
open
wider
by
hand
.
The
gap
between
the
stationary
primary
contacts
(
5
)
and
the
movable
primary
con
-
tact
(
8
)
measured
between
the
closest
points
,
should
be
3
5
/
8
"
to
3
15
/
16
"
.
To
change
this
gap
,
loosen
the
check
nut
(
17
)
Figure
7
,
and
turn
the
adjusting
nut
(
18
)
on
stud
(
19
)
.
Screwing
the
adjusting
nut
down
will
decrease
the
primary
contact
gap
.
Tighten
the
check
nut
and
re
-
measure
the
contact
gap
(
close
and
trip
the
breaker
before
checking
the
measurement
)
.
Whenever
the
primary
contact
gap
is
changed
,
the
primary
contact
wipe
should
be
rechecked
and
,
if
necessary
,
readjusted
.
WHEN
WORKING
ON
THE
MECHANISM
IN
THE
CLOSED
POSITION
,
KEEP
FINGERS
CLEAR
OF
THE
LINKAGE
,
AS
ACCIDENTAL
TRIPPING
CAN
CAUSE
SEVERE
INJURY
.
Primary
Contact
Wipe
Refer
to
Figure
9
,
when
the
breaker
is
closed
the
stationary
primary
contacts
(
1
)
should
rise
from
1
/
4
"
to
5
/
16
"
.
Before
checking
this
dimen
-
sion
be
sure
the
mechanism
is
re
-
set
so
that
the
prop
pin
(
13
)
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
)
.
Screw
-
ing
up
on
the
adjusting
nut
will
decrease
the
primary
contact
wipe
,
down
will
increase
it
.
Tighten
the
check
nut
,
close
the
breaker
and
recheck
the
wipe
.
With
the
primary
contact
wipe
correctly
adjusted
,
the
clearance
between
the
contact
arm
(
6
)
Fig
-
ure
9
and
the
buffer
block
(
3
)
should
be
1
/
16
"
or
greater
when
the
breaker
is
fully
closed
.
Trip
Latch
Wipe
Refer
to
Figure
7
.
The
wipe
of
the
trip
latch
(
8
)
on
the
trip
roller
(
9
)
should
be
from
'
3
/
16
"
to
1
/
4
"
.
This
can
be
measured
by
putting
a
film
of
grease
on
the
latch
(
8
)
,
closing
the
breaker
part
way
,
and
tripping
.
The
mechanism
has
the
proper
trip
latch
wipe
when
the
latch
rests
against
the
stop
pin
(
23
)
.
No
adjustment
is
provided
and
a
visual
inspection
is
usually
all
that
is
required
.
If
this
setting
is
not
correct
,
look
for
insufficient
travel
of
the
trip
shaft
(
7
)
.
Trip
Armature
Travel
Refer
to
Figure
7
.
The
trip
armature
(
4
)
should
have
7
/
32
"
to
9
/
32
"
travel
before
the
trip
latch
(
8
)
starts
to
move
.
This
can
be
adjusted
by
moving
the
trip
coil
support
(
2
)
and
/
or
by
adjusting
the
trip
armature
screw
(
12
)
Figure
11
.
A
locking
screw
located
behind
the
trip
armature
screw
must
first
be
loosened
.
Retighten
locking
screw
after
making
adjustment
.
Release
Latch
Wipe
Refer
to
Figure
6
.
The
wipe
between
the
release
latch
(
8
)
and
roller
(
6
)
should
be
3
/
16
"
to
1
/
4
"
.
If
re
-
setting
is
required
,
loosen
,
set
,
and
re
-
tighten
adjustment
nut
and
screw
(
10
)
.
Release
Latch
Monitoring
Switch
Refer
to
Figure
6
.
The
release
latch
must
be
fully
re
-
set
and
the
latch
monitoring
switch
(
13
)
operated
before
the
motor
will
start
.
When
the
latch
is
fully
reset
the
clearance
between
the
switch
striker
arm
and
the
switch
mounting
bracket
(
14
)
is
1
/
32
"
or
less
,
this
can
be
adjusted
by
bending
the
striker
arm
.
Figure
10
.
(
8039618
)
Adjustable
Coupling
For
i
Making
Primary
Contact
Wipe
Adjustments
1
.
Operating
Rod
2
.
Operating
Rod
Pin
3
.
Adjusting
Nut
4
.
Check
Nut
5
.
Stationary
Primary
Contacts
6
.
Yoke
7
.
Contact
Arm
8
.
Movable
Primary
Contacts
Motor
and
Relay
Switches
Refer
to
Figure
6
.
With
the
closing
springs
blocked
rotate
the
switch
cam
(
2
)
until
the
switch
11
Courtesy of NationalSwitchgear.com

GEK
-
41902
Magne
-
blast
Circuit
Breaker
;
W
,
Figure
11
.
(
8039585
)
Auxiliary
Switch
and
Trip
Coil
1
.
Open
-
Close
Indicator
2
.
Auxiliary
Switch
3
.
Prop
Spring
4
.
Trip
Latch
Spring
5
.
Spring
Discharge
Crank
6
.
Cotter
Pin
7
.
Trip
Coil
Support
8
.
Trip
Coil
9
.
Mounting
Bolts
10
.
Latch
Set
Screw
11
.
Trip
Latch
12
.
Trip
Arm
Screw
13
.
Manual
Trip
Lever
Figure
12
.
(
8034474
)
Positive
Interlock
Switch
1
.
Positive
Interlock
Shaft
2
.
Switch
Arm
3
.
Switch
Support
4
.
Interlock
Switch
5
.
Auxiliary
Switch
6
.
Switch
Support
7
.
Latch
Checking
Switch
8
.
Switch
Arm
9
.
Trip
Shaft
striker
(
3
)
has
traveled
the
maximum
amount
(
about
180
degrees
rotation
of
cam
)
.
At
this
point
the
clearance
between
the
striker
and
the
switch
support
(
5
)
should
be
1
/
32
"
or
less
.
This
can
be
adjusted
by
loosening
the
switch
support
mounting
bolts
(
4
)
and
rotating
the
support
.
Interlock
Switch
Wipe
to
its
maximum
travel
.
Now
check
the
clearance
between
the
ratchet
tooth
and
the
latching
pawl
.
The
clearance
should
be
approximately
equal
for
both
the
driving
and
latching
pawls
and
not
less
than
.
015
”
in
either
case
.
If
adjustment
is
required
for
either
pawl
the
springs
must
first
be
fully
charged
and
blocked
.
Loosen
seven
motor
support
bolts
(
2
)
Figure
1
and
move
entire
motor
assembly
to
the
rear
if
the
clearance
is
under
the
minimum
at
the
latching
pawls
,
and
to
the
front
if
the
clearance
is
under
the
minimum
at
the
driving
pawl
.
Move
the
motor
assembly
approximately
twice
the
dimensional
in
-
crease
required
at
the
pawl
.
Be
certain
the
motor
assembly
is
moved
straight
forward
or
rearward
and
tighten
the
one
bolt
on
the
‘
right
side
of
the
mounting
frame
first
to
assure
proper
alignment
.
After
tightening
the
remaining
bolts
the
springs
should
be
released
and
the
clearance
again
checked
as
described
above
.
Refer
to
Figure
12
.
With
the
positive
interlock
in
the
reset
,
or
normal
position
the
clearance
between
the
interlock
switch
arm
(
2
)
and
the
switch
mounting
plate
(
3
)
should
be
1
/
32
"
or
less
.
This
can
be
adjusted
by
bending
the
switch
arm
.
Driving
Pawl
Adjustment
Refer
to
Figure
4
.
The
driving
pawl
(
8
)
must
advance
the
ratchet
wheel
(
6
)
sufficiently
on
each
stroke
to
allow
the
latching
pawls
(
2
)
to
fall
into
the
ratchet
teeth
.
This
should
be
checked
with
the
closing
spring
load
against
the
driving
members
.
With
the
mechanism
unblocked
,
hand
charge
the
closing
springs
with
the
manual
charging
wrench
until
they
are
slightly
more
than
half
charged
.
Slowly
rotate
the
charging
wrench
until
the
driving
pawl
has
traveled
through
its
return
stroke
and
check
the
maximum
clearance
between
the
pawl
and
the
ratchet
tooth
.
Rotate
the
charging
wrench
until
the
driving
pawl
has
advanced
the
ratchet
tooth
/
AUXILIARY
DEVICES
:
Latch
Checking
Switch
Refer
to
Figure
13
.
Charge
the
closing
springs
sufficiently
to
reset
the
mechanism
linkage
.
Rotate
the
trip
latch
(
4
)
by
pressing
the
manual
trip
lever
i
12
Courtesy of NationalSwitchgear.com

Magne
-
blast
Circuit
Breaker
UEK
-
41902
3
Figure
14
.
(
8034464
)
Plunger
Interlock
1
.
Plunger
Bolt
2
.
Washer
3
.
Breaker
Lifting
Rail
Figure
13
.
(
0114
C
5320
)
Latch
Checking
Switch
1
.
Switch
Support
2
.
Latch
Checking
Switch
3
.
Switch
Arm
4
.
Trip
Latch
5
.
Reset
Pin
Stop
6
.
Latch
Roller
7
.
Latch
Roller
Link
8
.
Latch
Roller
Pin
4
5
6
7
to
open
the
latch
checking
switch
(
2
)
.
Allow
the
trip
latch
to
reset
slowly
and determine
the
point
at
which the
contacts
are
made
by using
a
circuit
continuity
tester
(
light
indicator
,
bell
set
,
etc
)
.
The
contacts
of
the latch
checking
switch should
just
make
when the
gap
between the
trip
latch
(
4
)
and the
stop
pin
(
5
)
located
on
the latch
roller
link
(
7
)
is
1
/
16
"
.
There
should
be
a
minimum
of
1
/
64
"
between
the
switch
arm
(
3
)
and
the
switch
support
(
1
)
.
To
obtain
adjustment
of
the
latch check
-
ing
switch
,
bend the latch
checking
switch
arm
Figure
15
.
(
8034471
)
Driving
Elements
1
.
Mounting
Bolts
2
.
Manual
Close
Button
3
.
Eccentric
4
.
Retaining
Ring
5
.
Hex
Charging
Stud
6
.
Driving
Link
Motor
Support
8
.
Retaining
Ring
9
.
Motor
10
.
Fuse
7
.
(
3
)
.
Plunger
Interlock
Refer
to
Figure
14
.
With
the
breaker
in
the
closed
position
,
the vertical distance
"
A
"
from
the
top
of
the
plunger
bolt
(
1
)
to
the
bottom
of
the
breaker
lifting
rail
(
3
)
should
be
16
-
19
/
32
"
to
16
-
23
/
32
"
.
To
change
this
adjustment
,
add
or
remove
washers
(
2
)
.
Auxiliary
Fuses
Refer
to
Figure
15
.
On
breakers
with
a
"
C
"
or
"
K
"
suffix
,
a
set
of
protecting
fuses
(
10
)
are
mounted
on
the
front of
the breaker
.
These
fuses
are
the
primary
protective
devices
for
the
closing
control
circuit
on
those breakers
that
are
used
in
metal
-
clad
units
designed
for
solenoidoperatedbreakers
.
Inspection
and
Test
1
.
For
ease
in
reviewing
the
adjustments
,
the
following
are
recapitulated
:
a
.
Primary
contact
wipe
:
1
/
4
"
to
5
/
16
"
.
b
.
Arcing
contact
wipe
:
5
/
16
"
or
greater
gap
at
primary
contacts
.
c
.
Primary
contactgap
:
3
-
5
/
8
"
to
3
-
15
/
16
”
d
.
Trip
latch
wipe
:
3
/
16
"
to
1
/
4
"
with
trip
latch
resting against
stop
pin
.
e
.
Trip
armature
travel
7
/
32
"
to
9
/
32
"
.
f
.
Release
latch
wipe
:
3
/
16
"
to
1
/
4
"
.
Release
latch
monitoring
switch
:
Max
-
.
imum
clearance
1
/
32
"
.
g
.
13
Courtesy of NationalSwitchgear.com

GEK
-
41902
Magne
-
blast
Circuit
Breaker
tangent
to
the
lower
surface
of
the
probes
on
the
upper
runner
.
Proper
servicing
and
lubrication
of
the
breaker
and
its
operating
mechanism
should
maintain
these
speeds
and
no
adjustment
is
provided
.
Control
Power
Check
h
.
Motor
and
relay
switch
:
maximum
clearance
1
/
32
"
.
i
.
Interlock
switch
:
maximum
clearance
1
/
32
"
.
j
.
Driving
and
Latching
Pawl
:
minimum
clearance
to
ratchet
teeth
.
015
"
.
k
.
Latch
checking
switch
contacts
make
when
the
gap
between
the
trip
latch
and
the
stop
pin
is
1
/
16
"
.
l
.
Plunger
interlock
:
16
-
19
/
32
"
to
16
-
23
/
32
"
.
Check
all
nuts
,
washers
,
bolts
,
cotter
pins
,
and
terminal
connections
for
tightness
.
Inspect
all
wiring
to
make
sure
that
no
damage
has
resulted
during
installation
,
and
test
for
possible
grounds
or
short
circuits
.
After
the
breaker
has
been
operated
several
times
with
the
manual
charging
wrench
and
the
mechanism
adjustments
are
checked
as
described
,
the
operating
voltages
should
be
checked
at
the
release
coil
,
trip
coil
,
and
motor
terminals
.
Control
Power
for
electrical
operation
of
the
breaker
may
be
from
either
an
alternating
or
direct
current
source
.
The
operating
ranges
for
the
closing
and
tripping
voltages
as
given
on
the
breaker
nameplate
,
are
as
follows
:
2
.
3
.
w
Closing
Range
Tripping
Range
Nominal
Voltage
4
.
See
that
all
bearing
surfaces
of
the
mech
-
anism
have
been
lubricated
.
Refer
to
the
section
on
LUBRICATION
.
(
Page
16
and
Figure
17
)
.
5
.
Operate
the
breaker
slowly
with
the
manual
charging
wrench
and
note
that
there
is
no
excessive
binding
or
friction
and
that
the
breaker
can
be
moved
to
the
fully
opened
and
fully
closed
positions
.
6
.
See
that
any
place
where
the
surface
of
the
paint
has
been
damaged
is
repainted
immed
-
iately
.
7
.
Check
the
trip
coil
plunger
and
the
release
coil
plunger
to
see
that
they
move
freely
.
Opening
and
Closing
Speeds
24
v
d
-
c
48
v
d
-
c
llOv
d
-
c
125
v
d
-
c
220
v
d
-
c
250
v
d
-
c
115
v
a
-
c
230
v
a
-
c
14
30
v
d
-
c
60
v
d
-
c
125
v
d
-
c
140
v
d
-
c
250
v
d
-
c
280
v
d
-
c
125
v
a
-
c
250
v
a
-
c
34
28
50
v
d
-
c
115
v
d
-
c
130
v
d
-
c
230
v
d
-
c
260
v
d
-
c
125
v
a
-
c
250
v
a
-
c
80
60
70
90
160
120
180
140
95
95
190
190
If
the
closed
circuit
voltage
at
the
terminals
of
the
coil
or
motor
does
not
fall
in
the
specified
range
,
check
the
voltage
at
the
source
of
power
and
line
drop
between
the
power
source
and
breaker
.
When
two
or
more
breakers
operating
from
the
same
control
power
source
are
required
to
close
simultaneously
,
the
closed
circuit
voltage
at
the
closing
coil
or
motor
of
each
breaker
must
fall
within
the
specified
limits
.
The
closing
speed
of
the
arcing
contact
of
the
breaker
should
be
a
minimum
of
llfeet
per
second
.
This
represents
the
average
speed
of
the
movable
arcing
contact
from
a
point
3
"
before
the
tip
is
tangent
to
the
lower
surface
of
the
probes
on
the
upper
arc
runner
to
the
tangent
position
.
Electrical
closing
or
opening
is
accomplished
by
energizing
the
closing
or
trip
coil
circuit
.
Control
switches
are
provided
for
this
purpose
on
the
metal
-
clad
unit
.
It
is
also
possible
to
trip
or
close
the
breaker
manually
by
pressing
the
manual
trip
lever
(
8
)
Figure
5
or
the
manual
close
button
(
9
)
.
The
opening
speed
of
the
arcing
contact
should
be
a
minimum
of
12
feet
per
second
.
This
repre
-
sents
the
average
speed
over
3
"
from
the
point
when
the
tip
on
the
movable
arcing
contact
is
GENERAL
MAINTENANCE
General
every
2000
operations
,
or
once
per
year
,
whichever
comes
first
.
If
the
breaker
is
also
required
to
interrupt
fault
currents
during
this
period
of
time
additional
maintenance
and
replacement
of
parts
may
be
necessary
.
Safe
and
dependable
service
from
electrical
ap
-
paratus
and
power
systems
is
contingent
upon
re
-
liable
performance
of
power
circuit
breakers
.
To
obtain
maximum
reliability
the
breaker
should
be
inspected
and
maintained
on
a
regular
schedule
.
The
breakers
are
designed
in
accordance
with
ap
-
plicable
standards
which
require
that
they
be
capable
of
performing
up
to
5000
operations
for
1200
ampere
breakers
and
3000
operationsfor
2000
ampere
breakers
switching
rated
continuous
cur
-
rent
before
any
replacement
of
parts
should
be
necessary
.
This
requirement
is
based
on
the
breakers
being
serviced
,
or
maintained
,
at
least
BEFORE
ANY
MAINTENANCE
WORK
IS
PER
-
FORMED
,
MAKE
CERTAIN
THAT
ALL
CONTROL
CIRCUITS
ARE
DE
-
ENERGIZED
AND
THAT
THE
BREAKER
IS
REMOVED
FROM
THE
METAL
-
CLAD
DO
NOT
WORK
ON
THE
BREAKER
OR
UNIT
.
MECHANISM
WHILE
IN
THE
CLOSED
POSITION
UNLESS
THE
PROP
AND
TRIP
LATCH
HAVE
BEEN
SECURELY
WIRED
OR
BLOCKED
TOPRE
-
14
Courtesy of NationalSwitchgear.com

Magne
-
blast
Circuit
Breaker
GEK
-
41902
VENT
ACCIDENTAL
TRIPPING
.
DO
NOT
WORK
ON
THE
BREAKER
OR
MECHANISM
WHILE
THE
SPRINGS
ARE
CHARGED
UNLESS
THEY
ARE
SECURED
IN
THAT
POSITION
BY
THE
MAIN
-
TENANCE
SPRING
BLOCKING
DEVICE
.
little
or
no
inspection
unless
there
is
evidence
of
damage
to
the
arc
chutes
sides
or
contamination
in
the
throat
area
.
If
either
of
these
conditions
are
present
the
interrupters
should
be
removed
from
the
breaker
and
the
following
points
noted
:
1
.
The
throat
area
of
the
interrupter
should
be
cleaned
with
sandpaper
(
Do
Not
use
emery
cloth
or
other
metallic
abrasives
)
.
All
flat
areas
on
either
side
of
the
movable
arcing
contact
travel
should
be
sanded
.
Do
not
sand
or
otherwise
attempt
to
clean
the
ceramic
fins
of
the
arc
chute
sides
.
Heavily
contaminated
parts
should
be
re
-
placed
.
2
.
Cracks
which
have
formed
in
the
fins
of
the
arc
chute
are
to
be
expected
in
ceramic
materials
of
this
type
when
subjected
to
the
severe
heat
of
an
arc
.
These
cracks
do
not
interfere
with
the
operation
of
the
device
in
any
way
and
should
be
disregarded
.
3
.
If
the
arc
chute
has
suffered
any
mechanical
injury
due
to
dropping
or
accidental
striking
,
resulting
in
the
actual
breaking
off
of
fins
,
replacement
will
be
necessary
.
Small
broken
corners
on
the
exhaust
end
of
the
arc
chute
sides
will
not
interfere
with
its
performance
and
can
be
disregarded
.
4
.
The
plastisol
flexible
covering
for
the
pole
pieces
(
3
&
6
)
Figure
18
should
be
inspected
for
breaks
in
the
insulation
.
If
there
are
holes
or
breaks
in
the
insulation
they
should
be
repaired
or
the
part
replaced
.
Periodic
Inspection
The
frequency
of
the
inspection
and
maintenance
operations
required
should
be
determined
by
each
operating
company
and
will
depend
on
the
applica
-
tion
of
the
breakers
and
the
operating
conditions
.
Factors
which
should
be
considered
are
:
Import
-
ance
to
overall
plant
or
system
operation
;
number
of
operations
and
magnitude
of
currents
switched
by
breaker
;
frequency
of
fault
interruptions
;
and
the
atmospheric
conditions
in
which
the
breaker
nor
-
mally
operates
.
Extreme
conditions
of
dust
,
moisture
,
corrosive
gases
etc
.
,
can
indicate
that
inspection
and
maintenance
will
be
required
more
frequently
than
every
2000
operations
.
Very
clean
dry
operating
conditions
with
low
current
switching
duty
can
justify
a
longer
period
of
time
between
inspections
.
Any
time
a
breaker
is
known
to
have
interrupted
a
fault
at
or
near
its
rating
it
is
recommended
that
the
breaker
be
inspected
and
necessary
maintenance
be
performed
as
soon
after
the
interruption
as
is
practical
.
The
following
instructions
give
the
items
that
should
be
included
in
an
inspection
and
general
recommendations
on
the
maintenance
of
breakers
.
i
Interrupters
Since
there
are
no
moving
parts
,
the
interrupters
of
a
magne
-
blast
breaker
will
normally
require
/
m
"
if
Tfoi
2
3
IS
1
J
4
S
Rear
Bushing
Supporting
Bolt
Upper
Interrupter
Support
Stationary
Arcing
Contacts
Movable
Arcing
Contact
Mounting
Bolts
Arc
Chute
Brace
Support
Bracket
Lower
Supporting
Bolt
Lower
Interrupter
Support
Interrupter
1
.
a
2
.
a
3
.
4
.
i
ill
i
5
.
6
.
5
7
.
6
8
.
9
.
10
.
8
11
.
:
9
10
11
!
Figure
16
.
(
8917442
A
)
Interrupter
Removed
Showing
Accessibility
of
Arcing
Contacts
15
Courtesy of NationalSwitchgear.com

!
GEK
-
41902
Magne
-
blast
Circuit
Breaker
Interrupter
Removal
and
Replacement
between
inspection
periods
should
be
wiped
off
,
and
if
dampness
is
apparent
,
heaters
should
be
installed
in
the
metal
clad
switchgear
to
insure
dryness
.
Insulation
Test
Refer
to
Figure
16
.
To
remove
the
interrupter
loosen
the
two
upper
supporting
bolts
(
2
)
and
the
one
lower
support
bolt
(
9
)
using
a
standard
3
/
4
"
wrench
.
Raise
the
assembly
approximately
3
/
8
"
and
slide
it
toward
the
rear
of
the
breaker
.
To
reassemble
the
interrupter
to
the
breaker
,
rest
the
lower
interrupter
support
(
10
)
on
the
support
bracket
(
8
)
.
Slide
the
arc
chute
forward
lifting
it
slightly
to
engage
the
supporting
bolts
(
2
)
in
the
slots
of
the
upper
interrupter
support
(
3
)
.
Check
to
assure
that
the
upper
insulation
is
prop
-
erly
positioned
within
the
barrier
suspended
from
the
stationary
contact
support
(
9
)
Figure
23
.
Tighten
the
supporting
bolts
(
2
and
9
)
Figure
These
bolts
serve
as
both
the
electrical
and
mechanical
connections
between
the
bushings
and
the
arc
runners
within
the
interrupter
.
Check
that
the
movable
arcing
contact
(
5
)
passes
between
the
probes
on
the
upper
arc
runner
(
5
)
Figure
19
without
touching
.
Breaker
Contacts
!
I
:
When
insulation
has
been
repaired
or
replaced
,
or
when
breaker
has
been
operating
in
adverse
moisture
conditions
,
it
is
recommended
that
the
insulation
be
checked
before
the
breaker
is
placed
back
in
service
.
A
standard
60
hertz
high
poten
-
tial
test
at
14
,
000
volts
RMS
for
one
minute
will
normally
indicate
whether
the
breaker
is
satis
-
factory
for
service
.
With
the
breaker
contacts
in
the
fully
opened
position
,
apply
the
test
potential
to
each
terminal
of
the
breaker
individually
with
all
other
terminals
and
the
breaker
frame
grounded
.
After
high
potential
tests
are
made
on
organic
in
-
sulating
materials
,
these
materials
should
be
inspected
for
visible
leakage
current
paths
,
and
necessary
action
must
be
taken
to
repair
or
replace
insulation
that
may
have
been
affected
by
moisture
absorption
.
If
the
breaker
secondary
wiring
is
to
be
given
a
high
-
potential
test
at
1500
volts
,
remove
both
of
the
motor
leads
from
the
terminal
board
.
Failure
to
disconnect
the
motor
from
the
circuit
may
cause
damage
to
the
winding
insulation
.
Lubrication
i
i
!
:
\
16
.
By
removing
the
box
barrier
the
movable
and
stationary
primary
contacts
and
the
movable
arcing
contacts
can
be
inspected
.
The
stationary
arcing
contacts
can
be
inspected
only
after
removing
the
interrupter
.
If
the
contacts
are
burned
or
pitted
,
they
can
be
made
smooth
with
a
fine
file
.
After
completing
inspection
of
the
contacts
,
check
the
contact
adjustments
as
specified
under
ADJUSTMENTS
.
In
order
to
maintain
reliable
operation
,
it
is
important
that
all
circuit
breakers
be
properly
lubricated
at
all
times
.
Most
of
the
bearings
and
rolling
surfaces
utilize
a
new
type
of
dry
lubrication
that
will
require
no
maintenance
and
will
last
the
life
of
the
equipment
.
Only
few
bearings
and
sur
-
faces
listed
in
the
chart
,
Figure
17
,
require
lubrication
.
These
have
been
properly
lubricated
during
assembly
at
the
factory
,
using
the
finest
grades
of
lubricants
available
.
However
,
even
the
finest
oils
and
greases
have
a
tendency
to
oxidize
with
age
,
as
evidence
by
hardening
and
darkening
in
color
.
Elimination
of
the
hardened
lubricant
is
essential
for
the
proper
operation
of
circuit
breakers
.
Also
frequent
operation
of
the
breaker
causes
the
lubricant
to
be
forced
out
from
between
the
bearing
surfaces
.
A
simple
lubrication
will
often
clear
up
minor
disturbances
which
might
be
mistaken
for
more
serious
trouble
.
Mechanism
A
careful
inspection
should
be
made
to
check
for
loose
nuts
or
bolts
and
broken
retaining
rings
.
All
cam
,
roller
,
and
latch
surfaces
should
be
inspected
for
any
evidence
of
damage
or
excessive
wear
.
Lubricate
the
mechanism
as
outlined
below
,
then
,
using
the
manual
charging
wrench
,
open
and
close
the
breaker
several
times
to
make
certain
that
the
mechanism
operates
freely
throughout
its
entire
stroke
.
Check
the
mechanism
adjustments
as
specified
under
ADJUSTMENTS
,
control
wiring
for
tightness
of
connections
and
damaged
insulation
.
Bushings
and
Insulation
Check
the
A
definite
lubrication
schedule
should
be
set
up
taking
into
consideration
the
frequency
of
operation
of
the
breaker
and
local
conditions
.
The
surface
of
the
bushings
should
be
kept
clean
and
unmarred
to
prevent
moisture
absorption
.
If
the
insulation
surface
should
become
damaged
,
it
should
be
sanded
and
cleaned
,
and
should
be
refinished
with
either
clear
varnish
or
clear
resin
.
Allow
to
dry
smooth
and
hard
.
All
other
insulation
parts
on
the
breaker
should
be
kept
clean
and
dry
.
Smoke
or
dust
collected
It
is
recommended
that
lubrication
of
the
breaker
and
its
operating
mechanism
be
a
part
of
the
per
-
iodic
inspection
and
maintenance
program
,
with
not
more
than
a
two
year
period
between
lubrications
.
It
is
also
recommended
that
all
circuit
breakers
be
operated
at
regular
intervals
,
at
least
once
a
year
,
to
insure
the
lubrication
is
in
good
condition
and
the
breaker
is
operable
.
m
r
:
a
i
;
16
1
|
i
1
Courtesy of NationalSwitchgear.com

Magne
-
blast
Circuit
Breaker
GEK
-
41902
The
lubrication
chart
,
Figure
17
,
is
divided
into
two
methods
of
lubrication
.
The
first
method
out
-
lines
the
maintenance
lubrication
which
should
be
performed
at
the
time
,
of
periodic
maintenance
,
and
requires
no
disassembly
.
The
second
method
out
-
lines
a
lubrication
procedure
similar
to
that
per
-
formed
on
the
breaker
at
the
factory
,
and
should
be
used
when
a
general
overhaul
of
the
breaker
is
necessary
.
General
Electric
Lubricants
D
50
H
15
andD
50
H
47
are
available
in
l
/
41
b
collapsible
tubes
.
It
is
so
packaged
to
insure
cleanliness
and
to
prevent
oxidation
.
i
LUBRICATION
AT
MAINTENANCE
PERIOD
ALTERNATE
LUBRICATION
(
REQUIRES
DISASSEMBLY
)
PART
Sleeve
Bearings
-
links
,
trip
shaft
,
etc
.
(
Teflon
coated
bearings
)
No
lubrication
required
No
lubrication
required
Sleeve
Bearings
-
main
crank
shaft
,
driving
pawl
lever
.
(
Bronze
or
cast
iron
)
Light
applica
-
tion
of
machine
oil
SAE
20
or
SAE
30
.
Remove
bearings
or
links
,
clean
per
instructions
and
apply
D
50
H
15
lubri
-
cant
liberally
.
Contact
Arm
Hinge
Assembly
Cup
bearing
Loose
rings
between
bushing
and
contact
arm
.
No
lubrication
required
.
Wipe
clean
and
apply
D
50
H
47
.
Roller
and
Needle
Bearings
Light
applica
-
tion
of
machine
oil
SAE
20
or
SAE
30
.
Clean
per
instructions
and
repack
with
D
50
H
15
lubricant
.
No
lubrication
required
.
Ground
surfaces
such
as
cams
,
ratchet
teeth
,
etc
.
(
Surfaces
coated
with
M
0
S
2
)
No
lubrication
required
.
Wipe
clean
and
apply
D
50
H
15
lubricant
.
Ground
surfaces
such
as
latches
,
rollers
,
prop
,
etc
.
Wipe
clean
and
apply
D
50
H
15
lubricant
.
Wipe
clean
and
apply
D
50
H
47
.
Wipe
clean
and
apply
D
50
H
47
.
Silver
plated
contacts
and
primary
disconnect
studs
.
Do
not
lubricate
Booster
Cylinder
Do
not
lubricate
Do
not
lubricate
Arcing
Contacts
Do
not
lubricate
Figure
17
.
Lubrication
Chart
17
Courtesy of NationalSwitchgear.com

I
GEK
-
41902
Magne
-
blast
Circuit
Breaker
the
alcohol
in
a
well
ventilated
room
;
excessive
exposure
to
the
fumes
is
sometimes
unpleasant
to
personnel
.
Washing
the
bearings
in
the
light
oil
,
draining
and
repacking
with
lubricant
D
50
H
15
should
follow
immediately
.
Bearings
that
are
pressed
into
the
frame
or
other
members
such
as
the
motor
support
(
7
)
Figure
15
,
should
not
be
removed
.
After
removing
the
shaft
and
inner
race
the
bearing
can
be
cleaned
satis
-
factorily
with
petroleum
solvent
or
a
similar
cleaner
and
a
stiff
brush
.
Follow
the
procedure
outlined
above
using
a
light
machine
oil
and
G
-
E
lubricant
D
50
H
15
before
reassembling
the
inner
race
and
shaft
.
METHOD
OF
CLEANING
BEARINGS
Whenever
cleaning
of
bearings
is
required
,
as
indicated
in
the
lubrication
chart
,
the
following
procedures
are
recommended
.
Sleeve
Bearings
The
sleeve
bearings
used
throughout
the
linkage
utilize
Teflon
surfaces
and
do
not
require
lu
-
brication
.
After
a
number
of
operations
,
the
sur
-
face
will
acquire
a
thin
black
film
.
Do
not
removfe
this
film
unless
there
is
evidence
of
outside
con
-
taminates
,
such
as
dry
or
hardened
grease
.
If
contaminants
are
present
they
should
be
removed
by
immersing
the
link
and
bearing
in
clean
petro
-
leum
solvent
,
or
similar
cleaner
,
and
using
a
stiff
brush
.
Do
not
remove
the
bearings
from
the
links
.
DO
NOT
USE
CARBON
TETRACHLORIDE
.
The
hinge
of
the
primary
contact
arm
(
24
)
Figure
8
,
should
be
disassembled
,
cleaned
,
and
lubricated
with
G
-
E
D
50
H
47
lubricant
at
general
overhaul
periods
.
The
main
shaft
bearings
(
24
)
Figure
7
and
the
bearings
in
driving
pawl
lever
(
10
)
Figure
4
,
should
be
removed
,
cleaned
,
and
lubricated
with
G
-
E
D
50
H
15
lubricant
at
general
overhaul
periods
.
Roller
and
Needle
Bearings
!
Rolling
Surfaces
:
A
number
of
rolling
and
rubbing
surfaces
in
the
mechanism
have
been
lubricated
with
a
baked
-
on
dry
,
molybdenum
disulfide
coating
.
This
lubri
-
cation
,
which
can
be
recognized
by
its
dark
,
almost
black
color
(
e
.
g
.
Face
of
switch
cam
(
5
)
Figure
2
)
requires
no
maintenance
and
should
last
the
life
of
the
breaker
.
;
3
l
!
Other
rolling
or
rubbing
surfaces
that
are
not
lubricated
with
molybdenum
disulfide
should
have
the
dried
,
dirty
grease
removed
and
a
thin
film
of
fresh
lubricant
D
50
H
15
applied
.
MAINTENANCE
Magne
-
blast
breakers
used
for
switching
arc
furnaces
or
capacitors
will
require
more
frequent
and
more
detailed
inspection
and
maintenance
because
of
the
repetitive
nature
of
the
applications
.
The
following
schedule
is
recommended
for
such
breakers
:
A
.
Every
500
Operations
,
or
Every
Six
Months
-
Whichever
Comes
First
:
i
il
Refer
to
Figure
7
.
The
cam
follower
bearings
(
6
)
,
latch
roller
bearing
(
9
)
,
and
cam
shaft
bearings
(
25
)
should
be
removed
from
the
mechanism
and
the
inner
race
disassembled
.
They
should
then
be
placed
in
a
container
of
clean
petroleum
solvent
or
similar
cleaner
.
TETRACHLORIDE
has
become
badly
oxidized
,
it
may
be
necessary
to
use
alcohol
(
type
used
for
thinning
shellac
)
to
remove
it
.
Ordinarily
,
by
agitating
the
bearings
in
the
cleaning
solution
,
and
using
a
stiff
brush
to
remove
the
solid
particles
,
the
bearings
can
be
satisfactorily
cleaned
.
Do
not
handle
the
bearings
with
bare
hands
as
deposits
from
the
skin
onto
the
bearings
are
inductive
to
corrosion
.
If
the
bear
-
ings
,
are
touched
,
the
contamination
can
be
removed
by
washing
in
alcohol
.
After
the
bearings
have
been
thoroughly
cleaned
,
spin
them
in
clean
new
light
machine
oil
until
the
cleaner
or
solvent
is
entirely
removed
.
Allow
this
oil
to
drain
off
and
then
repack
then
*
immediately
with
G
-
E
lubricantD
50
H
15
being
sure
all
metal
parts
are
greased
.
The
inner
races
should
then
be
assembled
.
il
W
I
n
I
!
I
id
ii
'
i
DO
NOT
USE
CARBON
If
the
grease
in
the
bearings
•
i
^
1
I
•
i
8
1
.
Remove
the
box
barriers
.
2
.
Wipe
all
insulating
parts
clean
of
smoke
deposit
and
dust
with
a
clean
dry
cloth
,
including
the
bushings
,
and
the
inside
of
the
box
barriers
.
3
.
All
flat
parts
in
the
throat
area
of
the
interrupters
should
be
thoroughly
clean
-
ed
by
using
sandpaper
.
This
cleaning
should
be
performed
any
time
the
inter
-
rupter
is
removed
.
The
fins
on
the
arc
chute
sides
should
not
be
cleaned
.
Whenever
the
interrupter
is
removed
,
loose
dust
and
dirt
should
be
blown
out
before
replacing
arc
chutes
.
Throat
insulation
which
is
heavily
contaminated
should
be
replaced
.
B
.
Every
2000
Operations
,
or
Every
Six
Months
Whichever
Comes
First
:
1
.
In
addition
to
the
servicing
done
each
500
operations
,
the
following
inspection
should
be
made
and
work
done
when
required
.
n
11
i
ill
11
I
1
I
if
x
m
NOTE
:
If
it
becomes
necessary
to
clean
the
bearings
in
alcohol
(
shellac
thinner
)
,
be
sure
the
alcohol
is
perfectly
clean
,
and
do
not
allow
the
bearings
to
remain
in
the
alcohol
more
than
a
few
hours
.
If
it
is
desirable
to
leave
the
bearings
in
the
alcohol
for
a
longer
time
,
an
inhibited
alcohol
such
as
is
used
for
anti
-
freeze
should
be
used
.
Even
then
the
bearings
should
be
removed
from
the
alcohol
within
twenty
-
four
hours
.
Precautions
against
the
toxic
effects
of
the
alcohol
must
be
exercised
by
wearing
rubber
gloves
and
by
using
11
!
|
!
l
m
I
!
HI
HI
18
Courtesy of NationalSwitchgear.com

Magne
-
blast
Circuit
Breaker
GEK
-
41902
positions
.
Its
electrical
operation
should
then
be
checked
using
either
the
test
cabinet
or
the
test
couplers
.
C
.
After
Every
10
,
000
Operations
:
1
.
In
addition
to
the
servicing
done
each
2000
operations
,
the
interrupters
should
be removed
from
the
breaker
and
dis
-
assembled
to
permit
a
detailed
inspec
-
tion
of
insulation
,
blow
-
out
coils
,
arc
runners
and
assemblies
which
can
become contaminated
by
arc
products
.
2
.
The blow
-
out
coils
should be
carefully
examined and
if
the
insulation has
been
cracked
,
shrunk
or
eroded
from
arc
action
and heat
so
that
the
turns
of
the
coils
are
not
fully
insulated
from
each
other
,
the coils
should
be
replaced
.
All
connections
should
be
checked
for
tightness
.
3
.
The
arc
runners
should
be
inspected
and
replaced
when
any
part
of
their
area
has been reduced
to
25
%
of
the
original
metal thickness
as
a
result
of
arc
erosion
.
2
.
Primary
Contacts
(
3
and
10
Figure
23
)
.
Inspect
the
condition
of
the
stationary
contact
fingers
and
movable
contact
blocks
.
Badly
pitted
or
burned
contacts
should be
replaced
.
(
Note
:
Burned
primary
contacts
indicate
the
probable
need
for
arcing
contact
replacement
*
)
If
the
contact
surfaces
are
only
rough
-
ened
or
galled
,
they
should
be smoothed
with
crocus
cloth
or
draw filed
.
After
contact
dressing
the
primary
contacts
should
be
greased
lightly
with
D
50
H
47
.
3
.
Arcing
Contacts
(
6
and
27
Figure
8
)
.
When
the
arcing
contact
wipe
is
less
than
the
minimum
specified
under
AD
-
JUSTMENTS
,
the
contacts
should be
replaced
.
inspected
for
uneven
wear
and
/
or
dam
-
age
using
a
mirror
to
inspect
the
stationary
contacts
.
Normally
it
will
not
be
necessary
to
remove
the
inter
-
rupters
for
this
2000
operation
ser
-
vicing
unless
inadequate
wipe
or
con
-
tact
condition
indicate
a
need
for
re
-
placement
.
If
the
interrupters
are re
-
moved
,
the
contact
braids
,
and other
parts
subject
to
arcing
should
be
check
-
ed
for
possible
cleaning
or
replacement
.
Do
not
grease
the
arcing
contacts
under
any
circumstances
!
‘
1
'
a
The
contacts
should be
4
.
Check
the
stationary
arc
contacts to
assure
that
the
arcing
contacts
are
in
good
condition and
that
their
connections
are
tight
.
5
.
Insulating
material
that
is
carbonized
and
cannot
be
satisfactorily
cleaned
should
be
replaced
.
6
.
Any
parts
damaged
or
severely
burned
and
/
or
eroded
from
arc
action
should
be
replaced
.
NOTE
:
Fine
cracks
may
develop
in
the
fins
of
the
arc
chute
sides
.
This is
to
be
expected
with
ceramic materials
when
subjected
to
the
high
heat
of
an
arc
and
may
be
disregarded
unless
they
are
long
and
present
a
possibility
of
fin
sections
breaking completely
off
.
Small
broken
corners
on
the
exhaust
end
of
the
arc
chute
will
not
interfere
with its
performance
and
can
also
be
disregarded
.
7
.
The
cup
bearing
and
the
contact
ring
at
the
hinge
point
of
the
contact
blade
should
be
disassembled
,
inspected
,
cleaned
,
and
relubricated
with
G
-
E
contact
lubricant
D
50
H
47
.
The
contact
ring
should
be
inspected
for
wear
and
replaced
when reduced
in
thickness
to
less
than
1
/
32
"
.
When
reassembling
the
cup
bearing
,
be
sure
the
cotter
pin
is
properly
assembled
in
the
castle
nut
on
the
hinge
pin
(
7
)
Figure
23
.
This
assures
proper
contact
pressure
at
the
hinge
.
4
.
Check
the
breaker
and
mechanism
ad
-
justments
as
summarized
under
IN
-
SPECTION
AND
TEST
.
The
necessary
readjustments
should be
made
as
de
-
scribed under
ADJUSTMENTS
.
5
.
The breaker and
operating
mechanism
should
be
carefully
inspected
for
loose
nuts
,
bolts
,
retaining rings
,
etc
.
,
all
cam
,
latch
and
roller
surfaces
should
be
inspected
for
damage
or
excessive
wear
.
The buffer
blocks
and
their
retainers
on
the bottom
of
the
stationary
contact
support
should
be
inspected
for
possible
need
of
replacement
.
6
.
The
contacts
of
the control
relay
(
17
)
Figure
6
,
should
be
inspected
for
wear
and cleaned
if
necessary
.
7
.
Lubricate the
breaker
operating
mech
-
anism
in
accordance with instructions
under
LUBRICATION
,
page
16
and the
lubrication
chart
Figure
17
.
8
.
Inspect
all
wiring
for
tightness
of
con
-
nections and
possible
damage
of
in
-
sulation
.
After
the breaker
has been serviced
,
it
should
be
operated
manually
to
be
sure
there is
no
binding
or
friction
and
that
the breaker
contacts
can
move
to
the
fully
opened
and
fully
closed
9
.
19
Courtesy of NationalSwitchgear.com

r
GEK
-
41902
Magne
-
blast
Circuit
Breaker
D
.
Every
20
,
000
operations
or
Approximately
Every
Five
Years
-
Whichever
comes
first
:
1
.
The
breaker
should
be
given
a
general
inspection
and
overhaul
as
required
,
,
All
excessively
worn
parts
in
both
the
mechanism
and
breaker
should
be
re
-
placed
.
Such
wear
will
usually
be
indicated
when
the
breaker
cannot
be
adjusted
to
indicated
tolerances
.
This
overhaul
and
inspection
is
more
detail
-
ed
and
will
require
disassembly
of
mech
-
anism
and
breaker
operating
parts
.
2
.
All
roller
and
needle
bearings
in
die
operating
mechanism
should
be
dis
-
assembled
,
cleaned
,
and
repacked
with
G
.
E
.
lubricant
D
50
H
15
as
described
under
LUBRICATION
.
Remove
the
side
brace
(
5
)
,
and
pole
pieces
(
3
&
6
)
.
2
.
3
.
To
remove
the
upper
arc
runner
assem
-
bly
(
4
)
Figure
20
,
remove
assembly
bolt
(
1
)
Figure
18
.
Remove
the
assembly
bolts
(
15
)
Figure
18
to
remove
the
lower
brace
(
8
)
.
4
.
Remove
the
lower
interrupter
support
(
13
)
by
removing
the
assembly
bolts
(
14
)
and
the
connection
nut
(
8
)
Figure
20
.
5
.
0
}
At
this
point
,
the
throat
shields
(
5
)
Figure
20
,
and
the
lower
arc
runner
assembly
(
6
)
can
be
removed
.
6
.
The
stationary
primary
contact
fingers
(
3
)
Figure
23
,
should
be
disassembled
and
the
silver
-
plated
pivot
area
of
the
contact
and
contact
support
cleaned
lubricated
with
G
-
E
lubricant
3
.
Further
disassembly
of
both
the
upper
and
lower
arc
runner
assemblies
can
be
done
by
removing
the
various
screws
and
assem
-
bly
bolts
(
not
illustrated
)
as
shown
in
Figure
19
.
The
arc
chute
sides
(
6
)
Figure
19
,
can
also
be
separated
for
inspection
after
removing
assembly
bolts
(
2
&
4
)
Figure
7
.
and
D
50
H
47
.
8
.
The
breaker
and
operating
mechanism
should
be
serviced
as
described
for
every
2
,
000
operations
and
properly
adjusted
before
being
put
back
into
service
.
4
.
18
.
Reassemble
the
interrupter
in
the
reverse
order
.
The
following
items
should
be
noted
during
re
-
assembly
:
REPAIR
AND
REPLACEMENT
1
.
The
fins
of
the
arc
chute
sides
should
be
equally
spaced
and
aligned
before
bolting
together
.
The
front
edge
(
along
the
runner
)
of
the
two
arc
chute
sides
should
be
parallel
and
in
line
.
This
section
covers
the
proper
method
of
removing
and
replacing
those
parts
of
the
breaker
subject
to
damage
and
wear
that
may
require
repair
or
replacement
at
the
installation
.
IMPORTANT
:
UPON
COMPLETION
OF
ANY
REPAIR
WORK
,
ALL
BREAKER
AND
MECHANISM
ADJUSTMENTS
MUST
BE
.
CHECKED
.
STALLATION
,
paying
particular
attention
to
AD
-
JUSTMENTS
and
FINAL
INSPECTION
.
;
•
2
.
The
gap
between
the
fins
at
the
rear
of
the
arc
chute
sides
measured
at
least
1
"
in
from
the
back
end
of
the
arc
chute
(
See
Figure
21
)
should
be
1
/
64
"
to
3
/
32
"
.
3
.
Check
to
insure
that
electrical
connections
to
the
blowout
coils
are
tight
.
4
.
When
reassembling
the
arc
runner
as
-
semblies
,
check
that
the
spacers
are
cor
-
rectly
installed
.
5
.
Before
bolting
the
upper
supports
in
place
,
make
certain
that
the
upper
arc
runner
assembly
is
tight
against
the
arc
chute
side
so
that
the
gap
between
the
throat
insulation
(
7
)
Figure
19
,
and
the
arc
chute
sides
(
6
)
is
a
minimum
.
6
.
Make
certain
that
the
electrical
connections
(
2
&
8
)
Figure
20
are
tight
.
Reassemble
the
arc
chute
on
the
breaker
as
described
under
INTERRUPTER
REMOVAL
AND
REPLACEMENT
,
page
16
.
Refer
to
the
section
on
IN
-
I
-
ARC
CHUTE
(
To
inspect
or
replace
blow
-
out
coils
and
arc
runners
)
:
With
the
breaker
open
and
the
closing
springs
in
the
blocked
position
,
remove
the
box
barriers
(
7
)
Figure
8
.
The
interrupter
can
now
be
re
-
moved
as
described
under
INTERRUPTER
RE
-
MOVAL
AND
REPLACEMENT
page
16
.
To
disassemble
the
interrupter
after
it
has
been
removed
from
the
breaker
,
proceed
as
:
follows
:
NOTE
:
When
disassembling
the
arc
chute
and
its
components
some
small
washers
,
spacers
,
etc
.
,
will
be
found
that
cannot
be
identified
in
these
instructions
.
Care
should
be
taken
to
coUect
and
identify
these
items
so
they
can
be
reassembled
correctly
.
1
.
Remove
the
assembly
bolts
(
7
,
9
,
11
,
&
13
)
Figure
18
.
I
I
!
:
ti
1
I
1
/
j
U
}
11
20
h
Courtesy of NationalSwitchgear.com