Opening (Tripping) Mechanism - Eaton DSII Series Instructions For Installation, Operation And Maintenance

Instructional Book IB694C694-03
Figure 4-8 Emergency Spring-Charge on Power Operated Mechanism
The angular position of the close cam in Figure 4-7 corre-
sponds to the angular position of the drive plates and closing
spring crank arms shown in Figure 4-6. The trip latch is in
the tripped position and it will reset to the latched position
at the end of the spring charging stroke. The closing springs
are charged by counterclockwise rotation of the ratchet and
drive plates until the close cam stop roller meets the spring
release latch, as shown in Figure 4-7b.
Note in Figure 4-7b also that the lower end of the main drive
link with the main roller has swung upward and toward the
left, pushing the trip latch constraining link so as to rotate
the trip latch back to the reset position. This occurs at the
same time that the spring charge is complete and just
before the close cam stop roller strikes the spring release
latch. The position of the cam in Figure 4-7b corresponds to
the position of the drive plates in Figure 4-6a spring charged,
breaker open.
The breaker is now ready to be closed. Closing is started by
counterclockwise rotation of the spring release latch (Figure
4-7b). This removes the hold on the close cam stop roller,
and allows the force of the closing springs to rotate the
close cam counterclockwise and close the breaker. The link-
age is then in the position shown in Figure 4-7c. The close
cam has rotated approximately 180 degrees.
Ratchet Wheel
Hold Pawl
Stop Bracket
Emergency Charge Device
Emergency Charge Pawl
Emergency Charge Handle
The spring release latch can be rotated by two methods:
1. Spring Release Device (Paragraph 3-10.2, Figures 4-4 and
4-14)
2. Close Bar (through linkage shown in Figure 4-14b)

4-4 Opening (Tripping) Mechanism

The breaker is tripped open by counterclockwise rotation of
the trip shaft (Figure 4-7c). The trip shaft extends across the
left hand part of the breaker, from the left hand mechanism
side sheet to the left hand breaker side sheet.
Rotation of the trip shaft accomplishes breaker opening as
follows (Figure 4-7c): The main contacts (not shown) produce
a clockwise twisting force or torque on the pole shaft. This
is transmitted by the center pole lever downward through
the main drive link to the main roller. The main drive link at
the main roller is connected to the trip latch by the roller
constraining link. This force tends to
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