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Power Circuit
Breakers , GEK
-
7310 A
BREAKER MAINTENANCE
SAFETY PRECAUTIONS
WARNING
:
BEFORE
INSPECTING
OR
BEGINNING ANY MAINTENANCE
WORK
ON THE
BREAKER
,
IT MUST BE DIS
-
CONNECTED
FROM
ALL
VOLTAGE
SOURCES
,
BOTH POWER
AND CONTROL
,
AND THE
BREAKER
MUST BE IN THE
"
OPEN
"
POSITION
.
ALSO
,
BEFORE
WORK IS DONE ON THE
BREAKER
,
THE
CLOSING SPRING IS
TO BE
MECHANIC
-
ALLY
DISCONNECTED FROM THE CAM
-
SHAFT OF THE MECHANISM
.
WITH THE
SPRING DISCONNECTED
,
THE
BREAKER
MAY
BE
CLOSED SLOWLY
, USING
THE
MAINTENANCE
HANDLE AS SHOWN IN
FIG
.
5
.
service of each breaker in
turn
for
inspection and
maintenance
,
is
an
excellent
means
of
establishing
a
high level of service reliability
.
Maintaining
a
reasonable
stock of
recommended spare parts
will
be
a
good
means
of
ensuring
that maintenance work
will be done quickly
.
Maintenance work will
,
in
most cases
,
consist
of cleaning and
replacement
of
worn or
damaged
breaker
components
.
Most of
the following instruc
-
tions will comprise descriptions of replacement
op
-
erations and
any
adjustments that
may be
required
after
new
parts
are
installed
.
They will be equally
useful for adding accessories
to
breakers
not
orig
-
inally equipped with them
.
NOTE
:
Breakers withdrawn
from equip
-
ment must
have their draw
out
mechanism
cranked
to
the
"
connected
"
position
to
operate
normally
.
See Step
1 of
"
Pre
-
Service Check
"
instructions
.
GENERAL
Breakers should be cared for
through the im
-
plementation
of
a
systematic
maintenance program
.
Aperiodic inspection routine is recommended
.
How
frequently
an
inspection is made
of
an
individual
breaker will
depend
on
the circumstances of its
use
.
It
would be well
to
inspect
any breaker
at
least
once
a year
.
If it
is frequently operated
, or installed
in
an
area
of
high humidity
or a
dusty
,
dirty
atmos
-
phere
,
the frequency of maintenance inspections
should be increased
.
Under
extremely bad condi
-
tions
,
inspections might
be monthly
.
ARRANGING THE BREAKER FOR
SLOW CLOSING
Figure
11
shows how
to
disconnect the
closing
spring
from the mechanismrs camshaft
.
A
172
-
inch wrench is used
to remove
the hex
-
head
bolt
in
A
maintenance inspection
should
include
an over
-
all visual check and the observation of
a
few clos
-
ing and opening operations
.
If
the breaker is elec
-
trically operated
, at
least
one
electrical
operating
cycle should be observed
.
A close
inspection should
be made of
contacts
and the inner surfaces of the
arc
quencher side plates and inner
components
.
Contact
wipe
should be checked
as
described in the
maintenance section dealing with
contacts
.
If dirt
,
grease
,
or
any other foreign material is
found
on
any
parts
of the breaker
,
it should be
re
-
moved by
a
thorough and careful cleaning
.
Insu
-
lating
surfaces
should be checked for any conditions
that could
cause a
loss of
insulating properties
.
If
a
breaker has
interrupted
a
short circuit
,
its
contacts
should be
inspected
.
It
is good policy
,
if
a
number of breakers
are
in
-
cluded in
an installation
, to
have
one or more spare
breakers
to
install in the place of breakers
requir
-
ing
maintenance
work
.
In such
cases
,
a
rotating
program
,
providing for
a
periodic withdrawal from
Fig
.
11
.
(
8041833
)
Disconnecting closing spring
15
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