Siemens 5-GMI-350 - Page 36

Maintenance
&
Overhaul
Page
33
Replacement
of
Racking
Position
Switch
(
Device
LS
4
)
(
Figure
59
)
The
racking
position
switch is mounted
on
the
right
(
when
facing
the
front
of
the breaker
)
vertical mechanism side
sheet
.
The
switch
is
actuated
by
a
push
rod
,
whose
vertical
position
is
a
function of
breaker
racking
position
within
its
cell
.
Should
difficulty
be
suspected
with
the
racking
position
switch
,
be
sure
to
eliminate all
mechanical
reasons
for
difficulty
before
replacing
the
switch
.
The
switch is held
in
place
by
two
mounting
screws
.
Remove
the
two
screws
.
Mark
the
wires
,
and
remove
them
.
Next
,
replace
the
switch
.
Be
sure
to
use
the
same
configuration
of flat
washers
,
lock
washers and
nuts
as was
present
in
the
as
-
shipped
condition
.
Replacement
of
Spring
Charging
Motor
(
Device
88
)
Remove
the
quick
-
disconnect
terminals
.
Then
remove
the
screws
holding
the
motor
mounting
bracket
to
the breaker
housing
.
The
motor
slips
out
as a
complete
assembly
.
Check
and
replace
as
required
.
Replacement
of
Primary
Disconnect
Fingers
Figure
63
shows
removal
of
the bolt which
attaches
the
primary
disconnect
finger
assembly
to
the
primary
discon
-
nect
.
With
this bolt removed
,
the
finger
assembly
can
be
slid
off
the
retaining
arm
as
a
unit
.
Replace
burnt
fingers
or
broken
springs
as
necessary
.
Replacement
of
Vacuum
Interrupters
The
following
procedures
are
for
the removal and
replace
-
ment
of
the
vacuum
interrupters
.
»
Figure
59
.
Racking
Position
Switch
(
LS
4
)
.
Replacement
of
Dashpot
Assembly
The
principal
wear
points
of
the
dashpot
assembly
are
the
two
piston
rings
,
and the
mating
area
between the
push
rod
and crank
shaft
.
Figures
60
and
61
show
the
components
involved
in
removal
and
replacement
of
this
assembly
.
First
,
remove
the
left
and
center
retaining rings
from
pin
121
.
Next
,
push
pin
121
to
the
right
to
free
the
pin
from
the
dashpot
linkage
.
Next
,
remove
the
four
nuts
holding
the
dashpot
assembly
to
the
mounting
bracket
.
Check
the
condition
of
the
Teflon
piston
rings
and
replace
as
required
.
Figure
60
.
Dashpot
Assembly
.
»
Courtesy of NationalSwitchgear.com