Siemens GM-SG

Circuit
Breaker Positions
Racking
from
CONNECT
to
TEST
or
DISCONNECT
Position
1
.
This
procedure
is
essentially
the
same as
racking
to
connected
position
procedure
except
the
rotation is counterclockwise
.
2
.
Check
that
the
circuit
breaker is
open
.
3
.
Close
instrument door
.
4
.
Insert
racking
crank
(
see
"
Racking
Crank
Engagement
Procedure
"
)
and
rotate
counterclockwise about
54
turns to
a
positive
stop
and the
position
indicator
indicates
"
D
"
for
DISCONNECT
position
.
The
intermediate
TEST
position
is indicated
by
"
T
"
.
A
DANGER
A
.
Hazardous
voltages
.
Will
cause
death
or
serious
injury
.
De
energize
and
ground
the
equipment
before
checking
contact
penetration
.
Figure
45
.
Racking
Mechanism shown
in
DISCONNECT
position
.
The circuit breaker
racking
method has been
designed
to
be used
with
the circuit breaker
compartment
door
either
open
or
closed
;
however
,
it
is
recommended that
the door be closed and
securely
latched
during racking
.
Moving
the circuit breaker between the
CONNECT
and
TEST
or
DISCONNECT
positions
with
the
door
closed
provides
additional
protection
to
the
operator
and is
the recommended
procedure
.
Contact
Penetration
Make certain all electrical connections
to
both the
line
/
load and bus disconnects
are
de
-
energized
and
locked
out
.
This
can
be
verified
by blocking
the shutters
open
and
using
a
hot stick
potential
device
to
double
-
check that
all
disconnects
are
de
-
energized
.
Rack
the
circuit
breaker
completely
into
the
CONNECT
position
and then
withdraw
it
from
the
cell
.
Check
that the
contact
wipe
is about
3
/
8
"
(
10
mm
)
on
the cell
primary
disconnects
,
for
all circuit breaker
ratings
.
Racking
from
DISCONNECT
to
CONNECT
Position
1
.
Check
that the
racking
position
indicator shows
"
D
"
for
DISCONNECT
position
.
2
.
Check
that the
circuit
breaker is
fully
pushed
into
the cell
to
the
DISCONNECT
position
.
3
.
Check
that
the
circuit breaker is
OPEN
.
4
.
Secondary
disconnects
will
automatically
connect
as
the
circuit
breaker
moves
to
the
TEST
and
CONNECT
position
.
5
.
Close
circuit
breaker
compartment
door
.
6
.
Insert
racking
crank
through
round
opening
at
bottom
of
door and
onto
the
racking
screw
(
see
"
Racking
Crank
Engagement
Procedure
"
)
.
7
.
Push the
racking
crank
forward
to
move
the closed
circuit
breaker
racking
interlock
slide back
which
will
allow the socket
to
engage
the
square
head
on
the
racking
screw
.
Do
not
force
slide
as
it
is
interlocked
to
prevent
sliding
forward
when the
circuit breaker is closed
.
8
.
Rotate
the
racking
crank clockwise
about
54
turns
until
a
positive
stop
is
felt
and the
position
indicated shows
"
C
"
for
the
CONNECT
position
.
The
indicator
will
show
"
T
"
when
the circuit
breaker is
in
TEST
position
.
Closed
Circuit
Breaker
Racking
Interlock
The closed circuit breaker
racking
interlock is
designed
to
prevent
a
circuit
breaker
from
being
racked
from
TEST
to
CONNECT
and
vice
-
versa
with
the
primary
contacts
closed
.
Only
an
open
circuit
breaker
is
to
be
moved
between these
positions
.
Refer
to
Figure
47
.
The
trip
free
interlock slide
has
angle
-
shaped
members
(
Figure
47
,
item
60
)
that
project
from
the
right
side
of
the
racking
mechanism
and
engage
an
interlock member
from
the circuit breaker
.
The circuit
breaker interlock extends down
to
prevent
movement
of
the
trip
free
interlock slide
with
the
circuit breaker closed
.
When
engaged
,
the
racking
screw
is
not
accessible
to
the
racking
crank until the
circuit
breaker has been
opened
.
Note
:
Racking
handle
must
be removed
,
allowing
the interlock slides
to return to
their initial
position
.
The circuit breaker
may
now
be closed
mechanically
or
electrically
.
43
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