Auxiliary Switch; Ak Breakers; Adjusting Center-Pole Open Contact Gap; Contact Replacement - GE AK-2-50 Maintenance Manual

1. With outside poles open, loosen adjus tment
plate (10) of center pole on crossbar (9) by
freeing- .;bolt locking tab and loosening bolts (11).
_2. . If center-pole wipe or overlap is to be
increased, move the adjustment plate to the left;
if
it is to be decreased, move it to the right.
3. After proper adjustment is made, tighten
adjus tment plate bolts until plate is snug. Then
tap adjustment plate in such a way as to bring
lower edge of slot in plate to bear against bolt.
Tighten bolt until lockwasher is fully compressed.
Then form locking tabs over bolt heads so that
bolts are securely held in place.
NOTE:
If
the above adjustment has been made,
it is necessary to-recheck the outer-pole wipe.
If
this is outside the prescribed limits, correct
as described in POLE UNIT ASSEMBLY.
4.
If
proper wipe cannot be obtained within
the range of the adjus tment described above, it
will
be necessary to obtain further adjustment by
_means of the vertical -shims (14) provided for the
purpose. In order to accomplish this, proceed
as follows: ·
a. Separate the front -frame from the back
frame (see
SEPARATION OF FRONT AND REAR
FRAMES).
· b. Loosen -screw (13) and remove bolt (15).
c. Remove vertical shims (14) to decrease .
wipe; add to increase •.
d. Replace bolt
(i5)
and· tighten screw
(13).
e. Reassemble front and back frame.
Adiusting Center-pole Open
Contact G_ap
(Fig. 17}
Improper open contact gap of the center pole
may be adjusted by -the following procedur e.
1. Loosen screw (13) and bolt (15).
2. If gap i s
to
be increased, horizontal shims -
(14) should be remove· d , . If it is
to
be decreased,
they should be added. Shims may be removed by
sliding them to the front of the breaker. They
are ·slotted for easy r_ e moval. (Effect of this ad-
j1.:1stmen~ on contact wipe and overlap is negligible.)
3. Tighten hardware.
Contact Replacement ·
- Stationary Contacts
(Fig.
17)
-
.
1: Remove arc quencher (see ARC QUENCHER).
2. Remove s crew (5) from braid.
3. Drift out pin (4) and remove contacts.
4. Reassemble
in
reverse order with new
Low Voltage Power Circuit Breakers GEK-7303
contacts.
5. Check contact overlap anc;l wipe, and re-
adjust
if
necessary (see above).
Movable Contacts
(Fig.
17)
1. Remove arc quencher (see ARC _ QUEN-
CHER).
2. Remove tru-arc r etainers on right side of
pins (7) and (16).
3.
Drift pins
(7)
and (16) to the.left far enough
to free movable contacts.
4 .
Reassemble in reverse order with new
contacts.
5.
Check contact overlap and wipe and re-
adjust
if
necessary (see above}.
,---- -- - - 9
,-------a
- - - -- 7
,--- - -- 6
r---- - - 5
,---- 4
Fig.
18
(0133C9020) Auxiliary . switc~ linkag-e
· -standard breaker -
AUXILIARY SWITCH
AK BREAKERS
(Fig, 18)
The auxiliary switch is used to make and break
various control circuits as the circuit breaker is
opened and closed, The auxiliary switch
is
mounted
on the left side of thefrontframe. As the crossbar
(4)
moves, with the contacts, to the open or closed
position it operates a triangular link (6) through
an operating rod·
(5).
The triangular
link
rotates
the operating shaft
(8)
of the auxiliary switch, which,
through cams located on this shaft, opens and closes
the auxiliary switch contacts. The_ top terminals
of
the switch are "a"- contacts (open
when
the
breaker
is
open) and the bottom terminals are "b"
contacts (closed when U1e
broako;r
is open).
Repl~mmenl
(Fig. 18)
1. Disconnect all leads to auxiliary switch.
21