SECTION 8-Contact Maintenance (Cont.)
8.2
CONTACT ADJUSTMENT
AKR 30130H & 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
AKRJAKRU 30 uses three stationary main contacts and the
AKR 30H uses four.
The following wipe adjustment procedure is applicable
to all AKR-30 types:
1 .
Open the breaker, remove arc quenchers.
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.
46.
4.
Once the gap dimension is set, verify that the torque
required to just tum the adjustment nut is greater than
40
in-lbs. If less torque is required, carefully add LOCTITE
220
to the adjustment nut threads. Wipe off any excess LOC
TITE. Once the LOCTITE is set, recheck the torque valve.
5.
Repeat above procedure on the other pole units.
6.
Trip the breaker.
PIVOT
STUD
0.250•
MEASUREMENT POINT
FIG.
45
-
WIPE ADJUSTMENT 800 AMP
CONTACT STRUCTURE
FIG. 46 - WIPE ADJUSTMENT NUT-800 AMP CONTACT STRUCTUR E
34
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