GE AKR-30 Series Maintenance Manual page 214

SECTION 8-Contact Maintenance (Cont.)
8.3 CONTACT ADJUSTM ENT ­
AKR
50/SOH
The contact structure shown in Fig. 47 is used by all
AKR50 breaker types. This structure uses two movable
contact arms. Each arm acts against a stationary arcing, a
stationary i ntermediate and three stationary mains.
The following procedure is used to perform the wipe ad-
j ustment.
1 . O pen the breaker, remove arc quenchers .
2 . Arrange the breaker for slow-closing.
3. Select one pole of the breaker and place a th in sheet
or strip of tough insulating material , such as mylar, over the
stationary arcing and intermediate contacts. This stri p
should be about two inches wide and must prevent the
arcing and intermediate contacts from making contact
when the breaker is closed.
4. Using the ratcheting_maintenance handle, slow-close
the breaker with the insulation held in place. Examine the
i nsu lation to ma k e sure it "over-hangs" below the in­
termediate contacts, but not enough to cover the main con­
tacts.
36
&
50
AKRU
FIG. 47
1 600
-
5. Attach a conti nuity checker (bell-set, light, or ohm­
meter) between the upper and lower stud. The checker
shou ld indicate continuity exists.
6. Facing the breaker, turn the wipe adj ustment stud
shown in Fig. 47 clockwise until the checker i ndicates that
the main contacts are separated.
7. Turn the stud counter-clockwise unti l the main con­
tacts just touch.
8. From this point, advance the stud counter-clockwise
270 degrees. This will be 4-1/2 flats.
9. Once the adj ustment is complete, verify that the torque
required to j ust turn the adjustment nut is greater than 40
in-lbs. If less torque is requ i red , carefully add LOCTITE 220
or 290 to the adjustment nut threads. Wipe off any excess
LOCTITE. Once the LOCTITE is set, recheck the torque
valve.
1 0. Trip the breaker, remove the insulating strips.
1 1 . Repeat the above procedure on the other two poles.
AMP CONTACT STR UCTU R E