Siemens 5-GMI-350 - Page 18

Interrupter
/
Operator
Description
Page
15
Figure
27
shows
the
MOC
switch
operating
arm
that
pro
-
jects
from
the
right
side
of
the
circuit
breaker
,
just
above
the
bottom
rail
structure
.
The
MOC
switch
operating
arm
is
part
of
the
jack
shaft
assembly
,
and
directly
reflects
the
open
or
closed
position
of
the
breaker
primary
contacts
.
§
f
Figure
25
.
Mating
Disconnect
Block
Inside
Switchgear
.
Figure
27
.
MOC
Switch
Operating
Arm
.
As
the
circuit
breaker
is
racked
into
the
appropriate
position
inside
the
switchgear
,
the
operating
arm
passes
a
wiring
protective
cover
plate
,
and
engages
the
pantograph
linkage
shown
in
Figure
28
.
Operation
of
the
circuit
breaker
causes
the
pantograph
linkage
to
transfer
motion
to
the
MOC
switches
located
above
the
pantograph
.
The
‘
a
’
and
‘
b
’
contacts
can
be
used
in
relaying
and
control
logic
schemes
.
All
circuit
breakers
contain
the
MOC
switch
operating
arm
.
However
,
MOC
switches
are
provided
in
the
switchgear
only
when
specified
.
The
breaker
engages
the
MOC
auxiliary
switch
only
in
the
connected
(
operating
)
position
unless
an
optional
test
posi
-
tion
pickup
is
specified
in
the
contract
.
If
a
test
position
pickup
is
included
,
the
breaker
will
engage
the
auxiliary
switch
in
both
positions
.
(
Figure
28
)
.
Up
to
24
stages
may
be
provided
.
TOC
(
Truck
Operated
Cell
)
Switch
Figure
29
shows
the
optional
TOC
cell
switch
.
This
switch
is
operated
by
the
circuit
breaker
as
it
is
racked
into
the
Connect
position
.
Various
combinations
of
'
a
'
and
'
b
'
contacts
may
be
option
-
ally
specified
.
These
switches
provide
control
and
logic
indication
that
a
breaker
in
the
cell
has
achieved
the
Con
-
nect
(
ready
to
operate
)
postion
.
Figure
26
.
Auxiliary
Switch
.
(
Normally
Open
)
contacts
.
When
the
circuit
breaker
is
open
,
the
‘
b
’
switches
are
closed
and
the
‘
a
’
switches
are
open
.
MOC
(
Mechanism
Operated
Cell
)
Switch
Figures
27
and
28
show
the
principal
components
that
provide
optional
control
flexibility
when
operating
the
circuit
breaker
in
the
Test
and
Connected
positions
.
Courtesy of NationalSwitchgear.com