GE AM-4.16-250-9 - Periodic Inspection

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
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