Siemens GMI Series

Interrupter
/
Operator
Description
Spring Charging
Motor
-
Figure
19
shows
the
spring charg
-
ing
motor
mounted
at
the
bottom
of
the
left
side
of
the
circuit
breaker
housing
.
A
mounting
bracket holds the
motor
firmly
in
place
.
A
universal
motor
is used
to
permit operation
on
either
AC
or
DC
control
power
.
The
motor
control circuits call
for
automatic
charging
of
the
springs
by
the
motor
whenever control
power
is available
and
the
springs
are
discharged
.
The
springs automatically
re
-
charge
following
a
closing
operation
.
Electrical connections
to
the
motor
utilize
quick
disconnect
terminations
for
easy
inspections
or
removal
.
Close
Solenoid
,
Trip
Solenoid
and Anti
-
Pump
Relay
-
Figure
21
shows the
two
solenoids
controlling
operation
of
the
circuit
breaker
by
external electrical
signals
.
When
the
close solenoid is
energized
it
causes
the
two
closing
springs
to
be
released
from
their extended
or
charged
state
.
This
forces
the
three
insulating
push
rods
to
move
the
movable
vacuum
interrupter
contacts
vertically
upwards
,
and
close
the
circuit breaker
.
The anti
-
pump
relay
(
Figure
41
)
electrically
isolates
signals
to
the
close solenoid
such that
only
one
releasing
action
by
the
close solenoid
can occur
during
each
application
of
the close
command
.
The circuit
breaker
must
be
tripped
,
the
springs
recharged
and the
closing signal
removed
(
interrupted
)
before
the close solenoid
can
be
energized
the second
time
.
When the
trip
solenoid is
energized
,
it
allows rotation
of
the
jack
shaft
by
the
tripping spring
.
This rotation
pulls
the
insulating
push
rods
attached
to
the movable
contacts
of
the three
vacuum
interrupters
,
and the circuit breaker
contacts
are
opened
.
Electrical connections
to
the close solenoid and
trip
solenoid
are
made
through
quick
disconnect
terminations
.
Secondary
Disconnect
-
Signal
and
control
power
is deliv
-
ered
to
the
internal
circuits
of
the
breaker
by
an
arrangement
of
movable
contact
fingers
mounted
on
the
left
side
of
the
circuit breaker
.
These
fingers
are
shown
in
Figure
22
.
When the circuit
breaker
is racked
into
the Test
or
Connected
positions
in
the
metal
-
clad
switchgear
,
these disconnect
fin
-
gers
engage
a
mating
disconnect
block
on
the
inside
of
the
switchgear
shown
in
Figure
23
.
These electrical
connections
automatically disengage
when
the circuit breaker is
racked
from
the
Test
to
the
Disconnect
position
.
All
of
the control
power
necessary
to
operate
the
ci
rcuit
breaker
is connected
to
this disconnect block
inside
the
switchgear
.
The external
trip
and close circuits
and
status
indicators
are
also connected
to
this
same
disconnect
block
.
0
§
A
CAUTION
M
A
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m
Figure
22
:
Secondary
Disconnects
on
Circuit
Breaker
.
W
m
m
-
:
Figure
21
:
Close
(
Right
)
and
Trip
(
Left
)
Solenoids
.
21688
A
-
93
Figure
23
:
Secondary
Disconnect Inside
Switchgear
.
15
Courtesy of NationalSwitchgear.com