SECTION 7-Breaker Maintenance (Cont.}
The areas requiri ng l u brication are:
1 . Contacts Pivots - A t h i n fi lm on t he stat ionary
and movable contact assembly pivot surfaces. Refer
to Section 8. Do not lubricate the contact tips.
2. Racking Mechanism - The drive threa
?
s, jam b
nut/trunnion i nterface, thrust washer/col l ar mterface,
and the shaft support bearings. Refer to Section
7.13.
3. Manual Operating Handle - Lubricate the two pivot
areas associated with the adjustment l i n kage. Also,
t he hand le, mounting shaft/su pport bushi ng i nter
face. Refer to Section 7.2.
4. Flux Shifter - Lubricate pivoting and slidi ng sur
faces of the reset l i n kage. Refer to Sect ion 1 0.3.
5. Switchette - Lubricate the activator lever surface
that contacts the switchette button.
6. Mechanism - All accessible bearing and sliding sur
faces t hat have been factory l u bricated.
7. Pri mary Disconnects - Lubricate the finger contact
surface just prior to i nstal l i ng in switchgear or
l ubricate and t hen cover the d isconnect assembly to
protect from d ust, dirt, etc. Refer to Section 7.5
Before lubricating, remove any h ardened grease or d i rt
from the l atch and bearing surfaces. After l u bricating,
remove all excess lubricant to stop accumulation of dirt or
d ust. The use of cotton waste to wipe bearing surfaces
should be avoided. The cotton ravelings may become
entangled under the bearing surfaces and destroy the
surface of the bearing.
7.2 MANUAL HANDLE ADJUSTMENT
The adjustment linkage connects the handle assembly to
the chain drive mechanism which turns the cam shaft. The
length of this linkage provides the handle adjustment.
If the link is too long, the handle stroke cannot extend the
closing spring enough for it to go over center. In this event,
use the maintenance handle to complete the spring charg
ing. The breaker can then be closed and opened prepara
tory to further shortening of the link.
If the link is too short, charging is not possible.
The orig inal linkage design used a double-ended stud in
the l inkage center. A hex section in this stud allowed adjust
ing with an open-end wrench . When looking down on .the
breaker, turning the wrench clockwise lengthens the hnk.
The opposite motion shor.tens it. The range of adjustment
is 300 degrees. In the conf ined space available, each
wrench stroke imparts 1 5 degrees movement. The best
setting is approximately mid-range.
The present design is shown in Fig. 20. This linkage is
assembled together on a threaded stud. Adjustment is
accomplished by removing the upper linkage assembly
from the handle assembly and changing the linkage length
by turning the upper linkage up or down the threaded stud.
FIG . 20 - MANUAL HANDLE ADJUSTMENT
19
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