Siemens 5-GMI-350 - Page 40

Overhaul
Troubleshooting
(
continued
)
Possible
Causes
and Remedies
Symptoms
Problem
1
.
Nuisance
or
false
closing signal
to
secondary
disconnect
contact
13
.
Check
relay logic
.
Correct
as
required
.
2
.
Closing
coil
(
52
SRC
)
terminal
2
is
shorted
to
ground
.
Check
to
determine
if
problem
is
in
wiring
or
coil
.
Correct
as
required
.
1
.
Mechanical
failure
of
operating
mechanism
.
Check
and
contact
factory
or
authorized
service
shop
.
1
.
Secondary
control
power
is de
-
energized
or
control
power
fuses
are
blown
.
Correct
as
indicated
.
2
.
Damage
to
wiring
,
terminals
or
connectors
.
Check
and
repair
as
necessary
.
3
.
No
tripping
signal
to
secondary
disconnect
contact
1
.
Check for
continuity
and
correct
relay logic
.
4
.
Secondary
disconnect
contacts
1
or
2
are
not
engaging
.
Check
and
replace
if
required
5
.
Failure
of
trip
coil
(
52
T
)
.
Check
and
replace
if
necessary
.
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
.
Nuisance
or
false
close Electrical
problem
Mechanical
problem
Tripping
coil
,
or
solenoid
(
52
T
)
does
not
energize
.
There
is
no
tripping
sound
.
Circuit
breaker
will
not
trip
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
.
Tripping
sound
is heard
,
but breaker
contacts
do
not
open
.
1
.
Mechanical
failure of
operating
mechanism
.
Check
and
contact
factory
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
factory
or
authorized
service
shop
.
Nuisance
or
false
trip
Electrical
problem
Mechanical
problem
38
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