Siemens 5-GMI-350 - Page 39

Maintenance
&
Overhaul
Page
36
Vacuum
Interrupter
Replacement
1
.
Inspect
all
silver
plated
connection
surfaces
for
cleanli
-
ness
.
Clean
only
with
a
soft
cloth
and
solvent
.
Do
not
abrade
any
surface
.
2
.
Insert
the
replacement
vacuum
interrupter
into
the
lower
stab
support
with
the
evacuation
nipple
shown
in
Figure
66
facing
the
breaker
mechanism
housing
.
3
.
Slip
the
flexible
shunt
clamp
over
the
movable
end
of
the
interrupter
.
Replace
clamp
bolt
,
washers
and
nut
.
Finger
tighten
.
4
.
Position
upper
primary
disconnect
,
upper
stab
support
and
all
spacing
washers
over
the
fixed
contact
of
the
vacuum
interrupter
.
Insert
top
bolt
into
fixed
contact
.
Finger
tighten
.
5
.
Connect
upper
stab
support
to
the
upper
insulator
.
Tighten
all
bolts
holding
the
upper
stab
support
to
the
upper
insulator
.
6
.
Replace
bolts
and
associated
hardware
connecting
the
two
insulating
tie
bars
to
the
upper
stab
support
.
Tighten
.
7
.
Loosen
the
flexible
shunt
clamp
bolt
,
be
sure
clamp
is
properly
seated
to
the
base
of
the
interrupter
’
s
movable
contact
.
Use
two
socket
wrenches
to
tighten
the
clamp
nut
.
Tighten
the
nut
to
produce
a
torque
per
Table
6
.
Use
of
holding
and
torquing
wrenches
will
prevent
twisting
the
movable
contact
bellows
.
8
.
While
maintaining
use
of
the
two
wrenches
at
the
flexi
-
ble
shunt
,
tighten
the
bottom
bolt
into
the
movable
contact
.
Use
the
same
torquing
values
listed
in
the
preceding
Step
7
.
9
.
Tighten
the
top
bolt
holding
the
fixed
contact
and
upper
primary
disconnect
to
the
upper
stab
support
.
Use
the
torquing
values
listed
for
the
top
bolt
in
Table
6
.
10
.
Replace
the
bell
crank
to
jackshaft
connection
.
Use
new
“
X
-
Clips
”
to
connect
the
jackshaft
to
the
bell
crank
.
11
.
Perform
a
manual
spring
check
.
While
the
breaker
primary
contacts
are
Closed
,
check
to
be
sure
contact
wear
indicator
is
visible
.
<
Table
6
.
Torque
Limit
Chart
.
Flexible
Shunt
Clamp
Bolt
Top
Bolt
Breaker
Type
05
-
GMI
-
250
-
1200
-
58
05
-
G
MI
-
250
-
2000
-
58
15
ft
.
lb
.
±
2
ft
.
lb
.
(
20
Nm
±
2
Nm
)
30
ft
.
lb
.
±
4
ft
.
lb
.
(
40
Nm
±
4
Nm
)
30
ft
.
lb
.
±
4
ft
.
lb
.
(
40
Nm
±
4
Nm
)
60
ft
.
lb
.
±
8
ft
.
lb
.
(
80
Nm
±
8
Nm
)
All
Others
I
Figure
66
.
Inserting
New
Vacuum
Interrupter
.
Courtesy of NationalSwitchgear.com