Siemens 5-GMI-350 - Circuit breaker will not trip; Nuisance or false trip

Maintenance
&
Overhaul
Page
35
5
.
Using
two
wrenches
(
one
holding
,
one
torquing
)
,
loosen
the
nut
holding
the
clamp
(
and
flexible
shunt
)
to
the
movable
contact
.
Then
remove
the
clamp
,
and
the
mov
-
able
contact
of
the
vacuum
interrupter
is
now
free
.
6
.
Figure
65
shows the
mechanical connections
to
the
fixed
,
or
upper
,
contacts
of
the
vacuum
interrupter
.
Remove
the bolt
holding
the
upper
stab
support
,
the
upper
primary
contact
and
the
vacuum
interrupter
fixed
contact
together
.
7
.
Remove
the
four
bolts
holding
the
upper
end
of
the
two
insulating
tie bars
to
the
upper
stab
support
.
8
.
Remove
all
of
the bolts
holding
the
upper
stab
support
to
the
upper
insulator
.
Have another
person
hold the
vacuum
interrupter
and
upper
primary
disconnect
in
place
to
prevent
damage
that
might
be
caused
by
having
these
parts
fall
once
they
are no
longer
mechanically
connected
to
the circuit
breaker
.
9
.
Remove
the
vacuum
interrupter
.
Again
,
be
sure
to
ac
-
count
for
the
location and
sequence
of
each
spacing
and
lock washer
.
Use
two
socket
wrenches
to
hold both
the head and
nut
end
of
the
clamp
that
connects
the
flexible
shunt
to
the
movable
contact
.
There
are
holes
on
both
sides
of
the
lower stab
support
to
permit
insertion
of
sockets
that
will
prevent
twisting
of
the movable
contact
bellows
when
removing
the
movable
contact
bolt
.
While
holding
both socket wrenches
in
place
at
the
clamp
,
another
person
can
remove
the
movable
contact
bolt
by
rotating
the bolt head
counterclockwise
.
3
.
4
.
Upper
Stab
Support
Upper
Insulator
Upper
Primary
Disconnect
/
/
©
L
—
its
Rotating
Tie Bar
Lower
Primary
Disconnect
Clamp
I
'
1
Lower
Stab
Support
_
J
Remove
this
Bolt
to
Disconnect
Upper
Contact
of
Vacuum
Interrupter
Lower
Insulator
L
-
»
-
1
-
1
-
t
*
\
Top
Support
Stab
Assembly
:
•
-
-
Flexible
Shunt
/
o
'
Bell
Crank
A
Push
^
2
>
A
Rod
.
qtRmmu
w
D
=
S
>
/
\
s
-
m
I
®
I
Insulator
Figure
64
.
Removing
X
-
Clips
.
Figure
65
.
Disconnecting
Top
of
Vacuum
Interrupter
.
CAUTION
List
the
order
and
location
of
each
flat
and
lock washer
.
It
is
critical
that
these
spacing
washers be
replaced
in
their
exact
order
upon
reassembly
to
assure
proper
opera
-
tion
of
the
breaker
.
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