Siemens 5-GMI-350 - Page 43

Maintenance
&
Overhaul
Page
40
Troubleshooting
Continued
Possible
Causes
&
Remedies
Symptoms
Problem
6
.
Auxiliary
switch
NO
contacts
1
-
2
or
5
-
6
are
open
when
breaker
is
closed
.
Check
linkage
and
switch
.
Replace
or
adjust
as
necessary
.
1
.
Failure
of
tripping
spring
or
its
mechanical
linkage
.
Check
and
replace
if
required
.
Tripping
coil
(
52
T
)
energizes
.
No
trip
-
ping
sound
is
heard
,
and
breaker
contacts
do
not
open
(
i
.
e
.
,
they
remain
closed
)
.
Tripping
coil
(
52
T
)
energizes
.
Trip
-
ping
sound
is
heard
,
but
breaker
con
-
tacts
do
not
open
.
1
.
Mechanical
failure
of
operating
mechanism
.
Check
and
contact
fac
-
tory
or
authorized
service
shop
.
2
.
One
or
more
of
the
vacuum
inter
-
rupters
are
held
closed
.
Check
and
replace
as
necessary
.
1
.
Tripping
signal
remains
energized
on
secondary
disconnect
contact
1
.
Check
for
improper
relay
logic
.
1
.
Mechanical
failure
of
operating
mechanism
.
Check
and
contact
fac
-
tory
or
authorized
service
shop
.
Nuisance
or
false
trip
Electrical
problem
Mechanical
problem
«
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