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4 3
of
the
left
hand chassis side plate
.
This
sliding plate is
operated by
a
round folding
rod with
a
"
T
"
handle
,
extending from the
L
.
H
.
upper
corner
of
the mechanism
panel
.
Above
this rod
is
the
secondary
contact
levering handle
.
The round rod
is
notched
so as to
normally be keyed
to
the
mechanism
panel
.
Thus
,
when the breaker is
in the
test
position
,
the secondary
contact
block
is normally disconnected and in the forward
position against the
rear
of
the chassis
.
This
is done by the
floor interlock
and
automatic tripping levers pointed
out
in
Figs
.
6
c
and 9
c
.
In
operation
,
the
rear
end
of this
lever is pushed upward by a
cell
floor
cam
on
the very
first
movement
of
the breaker
from the
test
position
toward
the
energized position
,
or from the ener
-
gized position toward
the
test
position
.
The lifting
of this lever
,
through its
connected linkage
,
lifts the tripping trigger
,
and the floor
cam
holds it in this
tripped
position
as
long
as
the breaker is
not
at
one
of its limits of travel
,
an
attempt to
close the breaker while it
is
not
completely
in the energized
or
test
position
,
the mechanism will make a
trip
free
operation
and the breaker
contacts
will
not
close
.
When you
wish
to operate
the breaker
electrically
while it is in the
test
position
the folding bar
is
lifted
to
the
horizontal
position enough
to
unhook it from the panel
,
and pushed
to
the
rear
until the
cross
-
pin
goes into the slots
in the levering handle
,
as shown
in Figs
.
4 a and b
,
which is then
pressed down
to
make final
engagement of
the secondary
contacts
.
If there
is
AUTOMATIC FLOOR TRIPPING AND
CLOSING SPRING RELEASE
For further operating details
see
BASIC
OPERATING INSTRUCTIONS
.
On breakers with stored
energy mech
-
anisms
,
the floor interlock and automatic
tripping lever
also
acts to
lift the tripping
trigger
as
the
breaker
is withdrawn
from
the cell from the
test
position
.
This
,
to
-
gether with the
automatic
floor closing
spring release
,
acts
to
discharge the closing
spring and
open
the breaker
as
it
comes
from the cell
so
that it is completely dead
mechanically
.
The closing spring release
trigger is lifted
so
that
,
if
the closing
spring
is
charged , it will discharge the
spring by closing the breaker
if it
is
open
,
or by a trip free
operation
.
The floor trip
-
ping lever will then
open
the breaker if it
is
closed
,
as described
above
.
RAIL LATCH
The purpose
of
the rail latch is
as
follows
.
1
.
It prevents
accidental
damage
to
the
cell levering
-
in
device
screw or
the
nut
on
the breaker
,
latch
,
the
screw
and
possibly
nut
would be
damaged
if
the
breaker where pushed
into
the
cell
so as to
bump
the
nut
hard against
the end
of
the
screw
.
Without this rail
2
.
It holds the breaker
in the
test
position
.
The rail latch has
two
catching dogs
,
one
on each side of the
pivot
,
which
can
engage
notches on the guide rail
.
A
spring
normally holds the front dog down against
the rail
so
that
as
the breaker is pushed
into the cell
,
the front dog will
drop into
the
rear
notch and
prevent further move
-
ment
.
If
an attempt
is made
to
override
the latch
by
pressing down
on
it
as
the
breaker
is
rolled
in
,
the rear
dog
will
Thus
,
as
the breaker is withdrawn from
the
test
position
,
2 mechanical noises may
be heard
,
the closing
of the breaker and the
opening of the breaker
.
SECONDARY
CONTACTS
The
15
point secondary
contact
block
is
mounted
on
a
slidable plate on the inside
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