5.3 M ECHANISM OPERATION
Figures 1 OA, 1 OB and 1 OC show the mechaniSm com ..
ponents in the Closed, Trip ped and Reset positions. The
closing spring is in the charged position for all of these
details.
Closed Position -
As shown i n Fig. 1 0A, the movable
contacts are pushed against the stationary contacts by
the toggle linkage. The toggle linkage is held in position
through the engagement of its cam rol lers, item no. 5, with
the prop, item no. 2 and the secondary latch/roller item #6
·
and secondary latch #1 4 and trip latch #1 1 .
Tripped Position
-
The mechanism goes from the
Closed position to the Tripped position, shown i n Fig.
1 08, when the trip shaft, item no. 1 0, is rotated by either
the manual trip button or one of the other trip devices.
The trip latch, item no. 1 1 is assembled to the trip shaft.
When the trip shaft rotates, the trip latch disengages
from the secondary latch rol ler. The secondary latch
pivots, resu lting i n the col lapse of the toggle l i n kage.
This col l apse along with the opening spring, item no. 1 5,
shown in Fig . 1 0 C, causes the br;eaker contacts to open.
Reset Position
- The mechanism is shown in Fig.
1 OC. The closing cam, item no. 3, which is assembled to
the cam shaft, item no. 4, is rotated by the charging motor,
manual operating handle, or maintenance handle. The
cam engages the cam roller and partially extends the
toggle linkage. This allows the secondary latch item 1 4 to
pivot against the front frame as shown leaving a gap
between the trip latch and secondary latch roller. The
secondary latch is now in a position to engage with both
the trip latch and cam roller.
The breaker closes when the closing spring discharges
and rotates the cam item #3 against the cam roller item #5.
The toggle l i n kage is fully extended, pivoti ng the secon
dary latch from the front frame and engaging it with the
trip l atch and cam rol ler as shown in Fig. 1 0A.
When the breaker is closed and the closing spring
discharged , the upper cam roller item #5 is supported by
the cam rather than the prop. This is the position the
mechanism must be in to check contact adjustment, refer
to Section 8.
11
14
6
FIG. 1
OA
CLOSED
1 2
13 s
2 4
3
I
Jr
r I
d;
10 1 1
14 s
2. Prop
FIG. 108 TRIPPED
1 5
1 4
5
4
3
FIG. 1 0C RESET
1 1 . Tri p Latch
3. Cam
1 2. I nsu lated Coupling
4. Camshaft
5. Cam Rol ler
6.
Secondary Latch Roller
1 0. Tri p Shaft
13. Main Shaft
1 4. Secondary Latch
1 5. Opening Spring
5.4 CHARGING USING THE MAINTENANCE
HANDLE
The closing spring on electrically operated breakers can
be manually charged by using the maintenance handle
(5688386G 1 ) as shown in Fig. 1 1 . The triangular socket in
the maintenance handle mates with the mechanism cam
shaft extension on the front right side of the breaker.
Using the knob on the handle, it will be necessary to align
this socket to fit on the end of the shaft when the handle
is positioned
as
shown.
FIG.
1 1
- MAINTENANCE HANDLE
I NSTALLED ON CAMSHAFT EXTENSION
13
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