SECTION 8-Contact Maintenance (Cont.)
8.2
CONTACT ADJUSTMENT -
AKR 30/30H & AKRU
30
The contact structure of the AKR 30 and the AKRU 30
breakers is slightly different from the AKR 30H. Referring to
Fig. 44 A & B, both structures use one moveable contact
arm, and two stationary arcing contacts. However, the
AKR/AKRU 30 uses three stationary main contacts and the
AKR 30H uses four.
The following wipe adjustment procedure is applicable
to all AKR-30/30H & AKRU-30.
1 . Open the breaker, remove arc quenchers.
ADJUST GAP AT
MEASU R E M ENT
POINT TO
.060
±
.020 "
2. Slow-close the breaker. The cam roller must be sup-
t
ported by the cam and not the prop. Refer to section 5.3.
3. Select one pole and, using a flat or wire feeler gage,
measure the gap between the top contact and its pivot stud
as shown in Fig.
45.
As necessary, adjust the gap to 0.060
±
0.020 inch by turning the wipe adjustment nut shown in
Fig. 45 & 46.
4. Once the gap dimension is set, verify that the torque
required to just turn the adjustment nut is greater than 40
in-lbs. If less torque is required, carefully add LOCTITE
220 or 290 to the adjustment nut threads. Wipe off any
excess LOCTITE. Once the LOCTITE is set, recheck the
torque (value u p to 40 in.-lbs.) but d o not break loose.
5. Repeat above procedure on the other pole units.
6. Trip the breaker.
PIVOT
STUD
0.250 " M EASU R E M E N T POI NT
FIG. 45 - WIPE ADJUSTMENT 800A EXCEPT
AKR 30L AMP CONTACT STRUCTURE
FIG. 46
-
WIPE ADJUSTMENT NUT-800 AMP CONTACT STRUCTU R E
34
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