14
Interrupter/Operator Description
At the beginning of the charging cycle, ratchet pin (16) is at
the 6 o’clock position. The ratchet pin is connected to the
ratchet wheel. Upon being advanced by ratchet action to
the 12 o’clock position, this pin engages the drive arms (8)
which are keyed to the main cam shaft. Consequently,
counterclockwise rotation of the ratchet wheel causes the
ratchet pin to drive the main cam shaft counterclockwise.
When the ratchet pin reaches the 6 o’clock position, the
closing springs are fully charged. Driving pawl (24-1) is
disengaged, the spring condition indicator cam (18) has
rotated allowing the spring charged flag (132) to drop into
the lower (charged) position, which also operates the motor
cutoff switch (LS1) and spring charged switch (LS2) (258)
(see
Figures 17b
and
27
). The closing springs are restrained
fully charged by close hatchet (22) against close shaft (72).
Closing Mode (Figure 17b)
Energizing the close solenoid (265) pulls the solenoid
armature against the closing shaft actuator (75) and causes
the close shaft (72) to rotate approximately 15°. If the
closing springs are charged, the close hatchet (22) will be
released by this rotation allowing the main cam shaft (3) to
be driven by the closing springs. Depressing the manual
close button on the operator panel causes the rotation of
the close shaft (72) by the lower end of the close shaft
actuator (75). Rotation of the main cam shaft (3) in a
manual closing operation is identical to that of an electrical
closing operation. As the main cam shaft (3) rotates, the
cam follower (115) is driven by drive cam (20), and the
main link (120) is forced outwards, and rotation of the jack
shaft assembly (217) occurs. There are three drive links
attached to Point “A” of each of the three jack shaft drive
plates. Each drive link is connected to the movable contact
of one vacuum interrupter. Closing rotation (counterclock-
wise) of the jack shaft assembly closes the contacts of the
three vacuum interrupters. During closing operation,
rotation of jack shaft assembly (217) forces the opening
(i.e., tripping) spring into its charged position.
Trip Free Mode
If at any time during circuit breaker closing, the trip shaft
(79)
(Figure 14b)
operates as a result of either an electrical
or mechanical trip, trip hatchet (99) is free to rotate. When
the trip hatchet (99) rotates, cam follower (115) is
displaced by drive cam (20) without motion of the jack
shaft (217). Mechanical trip free operation is provided by
manual tripping, electrical tripping and/or the mechanical
interlocks.
Figure 14b:
Circuit Breaker Open—Closing Springs
Discharged.
Figure 15b:
Circuit Breaker Open—Closing Springs
Charged.
