GE AKR-30 Series Maintenance Manual page 200

SECTION 7 -Breaker Maintenance (Cont.)
7.5.1 R EPLACEMENT
Figs. 22, 23, 24, and 25 show the primary disconnect
assembly breakdown . Refer to these ill ustrations when
replacing the disconnects. Note the following details:
Fig. 25 - The position of the spacer i n the breaker stud.
The hole in the spacer must be positioned as
shown so it will align with the holes in the clip.
Fig . 24 - The engagement of the fi ngers with the re­
tainer. Also the location of the 'bowtie' spacers in
the fingers, both upper and lower.
&
Fig . 22 23 - The position of the upper and lower
retainers and, agai n , the 'bowtie' spacers.
7.5.2 ADJ USTMENT
The primary disconnect assembly is factory adjusted to
apply a force of 85-1 05 pounds on a 1 /2 thick copper bar
inserted between the upper and lower fi ngers . After instal­
lation of the disconnect assembly this force range is ob­
tained by tightening the locknuts to set the di mension
shown in Fig. 26 . 766" to .797" Note that this di mension
is measured between the top of the retainer and the
underside of the washer. Also note that no bar is inserted
between the fingers when setting this dimension.
FIG. 26 - PRIMARY FING E R ADJ USTMENT
7.6 AUXILIARY SWITCH
All electrically operated breakers and manual breakers
having shunt trips are supplied with auxili ary switches.
Depending upon the requi rements of the breaker's applica­
tion, the switch may contain from two to six stages. Usually,
each stage has one "A" contact and one "B" contact. "A"
contacts are opened or closed as the breaker is opened or
closed. "B" contacts are the reverse of this.
The auxil iary switch is mounted on the upper side of the
mechanism frame as shown in Fig. 27. A crank on the main
shaft operates the switch through an adjustable link which
connects it to the switch crank. The switch can be a G E
type "SB- 1 2 " or Electro Switch Type "1 01 " .
22
FIG. 27 - AUXILIARY SWITCH LIN KAG E
7.6.1 REPLACEM ENT
Either switch type may be d ismounted by removing the
two bolt screws which fasten it to the mechanism frame.
The GE SB-1 2 replacement switch should have its
cran k shaft set so that the arrow head on the end of the
shaft points as shown in Fig. 28A when the breaker is
open.
The Electro Switch replacement should have its crank
shaft set so that the horizontal line on the end of the shaft
is as shown in Fig. 288 when the breaker is open.
ARROW HEAD
FIG. 28A - GE SB-1 2
CRANK SHAFT POSITION
If a switch is added to a breaker having none, the ad­
j usting link will also have to be installed. This is connected
to the pin on the crank which is attached to the main shaft.
It is secured by means of a cotter pin.
7.6.2 ADJUSTM ENT
GE SB- 1 2
I f a new adjustable l i n k i s i nstalled , its length should b e
set, before installing, a t 6.375 i nches, between p i n centers.
After install ing a new switch, its operation should
checked. Viewing the switch from above, the contacts
toward the front of the breaker are normally the "B" con­
tacts. Even if a special switch is used, it is always the case
that the fi rst two stages nearest the crank have the "B"
contacts to the front, and the "A" contacts towards the
back. "A" contacts are closed when the breaker i s closed.
" "
B contacts are c losed when the breaker is open.
FIG. 288 - ELECTRO
SWITCH C RA N K S HAFT
be