Stored-Energy Manual Mechanism; Closing The Breaker; Inserting The Safety Pin; Replacement Of Mechanism Parts - GE AK-2-50 Maintenance Manual

Fig. 14C
Release Shaft Stop and Switchette - Fig. 14C
Adjust screw "E" to 1/32" clearance between
screw and lever with clearance on release arm
ta.ken up by pressing lever lightly forward. ·
Adjust switchette operation by adding washers
"F" under · cotter pin, · so that contact is made
when armature is adjusted as shown above.
The control relay or
(X)
relay is located on
the left side of the front frame channel. It may
be removed by disconnecting the wiring, loosening
the (3) two mounting screws and lifting it slightly
to admit the top mounting screw through the
keyhole mounting, in general, the entire -relay
should be replaced rather than changing coils
and contacts.
The anti-pump relay is located on the left
side of the front channel above the control relay.
The connections to this relay are soldered. Re-
mo~al of . the relay is straight forward. When
re-mstallmg use extreme care to avoid shorting
contact points of different voltage potential with
solder of
flux.
The closing · control relay consists of a strong
box solenoid with sufficient linkages to operate
the remotely located D switches.
Stored-Energy Manual Mechanism (Fig. 15) ·
AK-50-75-100
This breaker is equipped with a spring-charged
stored-energy mechanism similar to the mechanism
Low Voltage Power Circuit Breakers GEK-7303
used on theAK-50, -75 and-100 electrical breakers.
The closing springs (5) are charged by operating
·· the manual closing handle (22) on the front of the
breaker, instead of the closing motor as is the
case with the electrical breaker. Closing this
breaker is accomplished by pumping the operating
handle
!mu
complete cycles, first counterclockwise
through 120 degrees from its normal vertical
position and then clockwise back through 120
degrees from its normal vertical position and
then clockwise back through 120 degrees. When
approximately 70 degrees of the fourth clockwise
stroke have been completed, the closing springs,
which have been charged during the previous
strokes ot the closing handle, are driven over-
center and the breaker closes.
This mechanism consists basically of a closing
spring assembly, ratchet wheel and output crank
assembly, handle shaft and pawl assembly, and
the closing handle.
Closing the Breaker
(Fig. 15)
The first stroke of the closing handle causes
the ratchet pawls (21) attached to the handle shaft
(23), to engage the first tooth of the ratchet wheel
(17), thus beginning to charge the closing springs .
The subsequent closing handle strokes perform the
same function as the pawls (21) engage the teeth
in the ratchet wheel (17), thus rotating the ratchet
wheel and output crank (32) and completely charging
th_ e closing springs . This rotation of the ratchet
wheel and output crank is in a counterclockwise
direction from the lower· position, through slightly
more than- 180 degrees, to a position just beyond
dead center. In this position the closing springs
are free to release their energy, closing the breaker
at a high speed. · .
Inserting the Safety Pin
(fig_. 15}
1f
it is desired to slowly close the breaker
contacts to check contact wiEe- and sequence,·
operate the closing handle 3 1/2 complete cycles
as described above. At the end of the fourth
counterclockwise stroke and before performing
the fourth clockwise stroke, insert the safety
pin (3) into the hole (4) in the guide rod (6),
thus preventing the closing springs (5) from
releasing their energy to close the bre~er contacts.
Replacement
(Fig.
15)
1f
it 'is necessary to replace any of the mech-
anism parts, the following total procedure is
recommended. This procedure may be . halted
at the step required to replace any particular
part:
1. ·
Install the safety pin (3) as described.
above.
2. Separate the front and rear frames as
described under "SEPARATION OF FRONT AND
REAR FRAMES" "in the "MAINTENANCE" sect.ion
of these instructions.
.17