GE AM-4.16-250-6 - Page 19

Magne
-
blast
Circuit
Breaker
GEI
-
88761
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
.
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
.
Insulating
material
that
is
carbonized
and
cannot
be
satisfactorily
cleaned
should
be
replaced
.
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
.
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
.
6
.
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
.
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
.
9
.
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
19
1
-
~
?
W
;
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