Contact Adjustment - GE AKR-30 Series Maintenance Manual

8.4 CONTACT ADJUSTMENT­
AKRT 50/SOH
The contact structure shown in Fig. 48 is used by all
AKRT 50 breaker types. This structure is similar to the AKR
50 structure. There are two movable contact arms, each
acting against single stationary arcing and intermediate
contacts and four stationary mains.
There are two designs used to co nnect the movable
contact arms to the insulated link. This results in two con­
tact adj ustment procedures depending on which design
the breaker has .
In the origi nal design the two movable contact arms are
pi n-coupled to a metal driving link whose opposite end is
th readed and screws directly into the insulating link. This
arrangement om its the wrench-operated wipe adj ustment
stud provided on the AKR-30 and -50 frames. I nstead , wipe
is adj usted by detaching the driving link from the movable
contact arms and then rotating it with respect to the insu lat­
ing link.
On the AK RT-50 the proper amount of contact wipe
exists if, on a closed breaker, all of the stationary main
contacts have moved away from their stops. This condition
can be checked visually by removing the arc que nchers,
closing the breaker and verifying that all eight stationary
main contacts are " l ifted off" their stops. Should wipe ad­
j ustment appear necessary, proceed as follows:
FIG. 48 - 2000 AMP CONTACT STR U CTU R E
1 . Open the breaker.
2. Arrange the breaker for slow-closing.
3 . Selecting one pole, drift out the co upling pin and
detach the driving link from the movable contact arms.
4 . Screw the driving link completely into the insulating
link.
5. Back out the driving link two and one-half turns. Ex­
ceed this by whatever amount is necessary to properly
position the link with in the movable contact arms.
6. I nstall the cou pling pin and retainer rings.
7. U s i n g the m a i ntenance hand l e , slow-close the
breaker and observe that all eight stationary main contacts
move away from their stops. If this condition is not
achieved , ope n the breaker, again remove the cou pling pin
and back out the driving link an additional half turn .
8. Reassemble, reclose the breaker and recheck wipe.
9. Repeat the above procedure on the other two poles.
In the existing desig n , the metal driving l i nk uses the
same adj ustment as the AKR 50. To perform the wipe
adjustment on this design follow the procedure for the AKR
50, Section 8 . 3 .
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