Siemens 5-GMI-250 - Checks of the Primary Power Path

Maintenance
&
Overhaul
Page
21
Introduction
•
Pliers
•
Light
Hammer
•
Drift
Pins
:
1
/
8
,
3
/
16
and
1
/
4 in
.
diameter
Periodic
inspections
and maintenance
are
essential
to
ob
-
tain
safe
and
reliable
operation
of
the
GMI
circuit breaker
,
When
the circuit
breaker is
infrequently
operated
(
less
than
20
times
per
week
)
,
and is located
in
a
clean and
dry
indoor
location
,
annual
inspections
are
usually
satisfactory
.
When
the circuit
breaker is
operated
more
than
20
times
per
week
,
or
when adverse
environmental
conditions exist
,
more
fre
-
quent
inspections
may
be
necessary
.
This
part
of
the
manual is
designed
to
provide
general
guidance
for
maintenance
.
It
will
supplement
,
not
replace
individual maintenance
programs
based
upon
special
ex
-
perience
and
knowledge
of
specific
installations and
their
actual
operating
conditions
.
Recommended
Annual
Inspections
Periodic
inspections
occurring
at
annual
,
or more
frequent
,
intervals should include all the tasks shown
in
Table
1
.
Recommended
procedures
for
each
of
the
listed
tasks
are
provided
in
this
section
of
the manual
.
Table
1
.
Annual
Inspection
/
Maintenance Tasks
•
Checks
of
the
Primary
Power Path
•
Checks of
the
Interrupter
Operator
Mechanism
•
Electrical
Control
Checks
•
High
Potential Test
•
Inspection
and
Cleaning
of
Breaker Insulation
•
Functional
Tests
A
WARNING
»
Hazardous
voltages
and
high
speed
mechanical
parts
can
cause
death
or
severe
personal
injury
and
property
damage
.
For
a
“
quick
reference
”
to
these
tasks
see
“
Annual
Inspec
-
tion
Tasks
”
chart
at
the end
of
this section
.
Removal
from
Switchgear
Read
instruction
manual
,
observe
safety
instructions
and
limit
use
to
qualified
per
-
sonnel
.
Prior
to
performing
any
inspection
checks
or
tests
,
the
circuit
breaker
must
be removed
from
the
switchgear
.
The Instal
-
lation and Initial Functional Tests section describes
the
removal
procedure
in
detail
.
Principal
steps
are
repeated
here
for information
and
guidance
,
but
without the
details
of
the
preceding
section
.
1
.
The
first
step
in
the annual
inspection procedure
is
to
de
-
energize
the circuit breaker
.
Figure
39
shows the
outer
door
of
a
standard
switchgear
cubicle
opened
for
access
to
the
operator
panel
of
the circuit breaker
.
Recommended
Hand
Tools
Type
GMI
breakers
use
both
standard American and metric
fasteners
.
Metric
fasteners
are
used
for
the
GMI
vacuum
interrupters
.
American
fasteners
are
used
in
all
other
loca
-
tions
.
This list
of
hand
tools
describes
those
normally
used
in
disassembly
and
re
-
assembly
procedures
.
Metric
(
Vacuum
Interrupter
,
Only
)
•
Deep
Sockets
:
18
and
24
mm
•
Torque
Wrench
,
0
-
150
Nm
(
0
-
100
Ib
-
ft
)
American
(
All
Other
Breaker
Locations
)
•
Socket
and
Open
-
end
Wrenches
:
5
/
16
,
3
/
8
,
7
/
16
,
•
1
/
2
,
9
/
16
,
and
3
/
4
inch
Hex
Keys
:
3
/
16
and
1
/
4
in
•
Screw
Drivers
:
0.032
x
1
/
4
in
wide and
0.55
x
7
/
16
in
.
wide
Figure
40
illustrates the location
of
the
Trip
control
on
the circuit breaker
operator
panel
.
Depressing
the
Trip
pushbutton
opens
the
breaker
prior
to
removal
from
the
switchgear
.
The
second
step
in
the
removal
procedure
is
to
de
-
ener
-
gize
control
power
to
the circuit
breaker
.
Open
the
control
power
disconnect device mounted
above the
lower
breaker
or
below
the
upper
breaker
.
Review
Fig
-
ure
1
.
Rack
the breaker
to
the
Disconnect
position
.
2
.
»
3
.
Courtesy of NationalSwitchgear.com