Siemens GMI Series

Interrupter
/
Operator
Description
The
cylindrical
body
of
the
damper
is
secured
to
the
breaker
frame
,
with
a
yoke
.
The
damper
'
s
piston
and
striker
tip
protrude
from
the
opposite
end
of
this
cylinder
(
the
lower
end
as
installed
on
the
breaker
)
.
A
striker
block
is
fixed
within
an
outer
tube
,
which
is
guided
by
the
cylindrical
body
of
the
damper
.
The
end
of
the
outer
tube
is
attached
to
the
breaker
jack
shaft
.
The
outer
tube
and
(
inner
)
damper
remain
uncoupled
until
the
end
of
the
opening
operation
is
reached
.
At
this
time
,
the
tube
'
s
striker
block
contacts
the
damper
piston
,
to
begin
control
of
movable
contact
dynamics
.
Manual
Spring
Charging
-
Manual
charging
of
the
closing
springs
is
accomplished
using
a
lever
in
lieu
of
the
spring
charging
motor
.
Figure
20
shows
the
principal
components
of
the
manual
spring
charging
mechanism
.
The
manual
spring
charging
lever
is
inserted
into
a
rectangular
socket
in
the
hand
operator
.
This
socket
is
accessible
through
the
front
panel
of
the
circuit
breaker
.
Moving
the
lever
up
and
down
in
a
cranking
or
pumping
motion
causes
rotation
of
the
internal
spring
charging
components
.
Closing
and
Opening
Springs
-
The
stored
energy
assembly
consists
of
two
dual
closing
springs
and
a
single
opening
spring
.
Figure
19
shows
the
three
springs
and
their
linkages
to
the
charging
devices
.
The
two
closing
springs
are
con
-
nected
to
crank
arms
mounted
on
the
rotating
main
cam
shaft
.
The
closing
springs
are
extended
,
and
charged
,
by
rotation
of
the
crank
arms
connected
to
the
movable
ends
of
the
springs
.
The
fixed
ends
of
these
springs
are
attached
to
a
support
arm
,
which
in
turn
is
bolted
to
the
structure
of
the
circuit
breaker
.
The
opening
spring
is
connected
to
the
jack
shaft
.
When
the
circuit
breaker
closes
,
rotation
of
the
jack
shaft
causes
the
opening
spring
push
rod
to
compress
and
charge
the
opening
spring
.
Consequently
,
the
opening
spring
is
automatically
charged
whenever
breaker
contacts
are
closed
.
Trip
Free
Operation
-
The
GMI
circuit
breaker
is
mechanically
and
electrically
trip
free
.
This
important
function
enables
the
breaker
to
be
tripped
before
,
after
or
during
a
closing
opera
-
tion
.
Whenever
the
circuit
breaker
trip
shaft
is
moved
as
the
result
of
manual
or
electrical
signals
or
mechanical
interlocks
,
a
)
a
closed
breaker
will
open
,
b
)
a
breaker
in
the
process
of
closing
will
not
complete
the
close
operation
and
will
remain
open
,
or
c
)
an
open
breaker
will
not
be
able
to
be
closed
.
Damper
-
GMI
circuit
breakers
are
equipped
with
a
sealed
,
oil
-
filled
,
viscous
damper
,
or
shock
absorber
(
Figure
19
)
.
The
purpose
of
this
damper
is
to
limit
overtravel
and
rebound
of
the
vacuum
interrupters
'
movable
contacts
during
the
conclusion
of
an
opening
operation
.
The
damper
action
affects
only
the
end
of
an
opening
operation
.
Note
:
Manual
spring
charging
components
will
be
damaged
by
overcharging
.
Manual
charging
action
must
be
suspended
when
the
operator
sees
the
’
Charged
"
status
indicator
appear
on
the
front
panel
of
the
circuit
breaker
and
hears
the
sound
of
impact
against
the
internal
closing
latch
.
Figure
20
:
Manual
Charging
of
the
Closing
Springs
.
Figure
19
:
Closing
and
Opening
Springs
,
Spring
Charging
Motor
and
Damper
.
14
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