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Inspect arc chute sides for cracks or erosion and
replace if damaged. Use a flashlight to examine the
arcing contacts inside the arc chute. If contacts are
found to be burned or pitted over half of their surface, or
if the contacts are out of alignment, the arc chute
should be replaced.
CAUTION!
Slow closing or slow opening the switch using the
maintenance hub may result in bodily injury if care
is not taken to hold the operating handle firmly.
Be sure to hold the handle firmly while performing slow
closing or slow opening operations.
5.1.3 Flicker Blade Engagement Check
First, close the switch.
handle in the pipe-like maintenance hub welded to the
switch shaft (see Fig. 7) and slowly open the switch.
The flicker blades should remain engaged in their
contact fingers while the main blades open. When the
main blades clear the break jaws, they will hit a stop on
the flicker blade brackets and start the flicker blades out
of their contact fingers. The flicker blades will then snap
open from the forces in their charged torsion springs.
Inspect the tightness of the bolts securing the flicker
blades to their mounting brackets. Inspect the flicker
blade mounting bracket to insure that does not pivot up
and down on its mounting bolt.
pivoting is observed. Do not overtighten. To verify that
the mounting bracket bolt has not been overtightened,
push the flicker blade to the rear. It should rebound
smoothly.
Maintenance
Hub
Fig. 7
Use of Maintenance Hub
5.1.4 Interphase Barrier Inspection
Next, insert the removable
Tighten the bolt if
Check interphase barriers for carbon or metallic
deposits. Replace if deposits are present.
5.1.5 Cleanliness check
Wipe away any dust or dirt that may have accumulated
on the switch parts, paying close attention to insulators
and insulating material.
5.1.6 Mechanical Operation Check
Close and open the de-energized switch at least three
times to check the performance of the operating
mechanism.
5.2 Alignment Procedures
Check each of the following items for adjustment and
alignment. If out of adjustment and alignment, follow
the instructions given.
Failure to completely disconnect the switch from all
power sources prior to inspection may result in
severe injury or death.
The switch must be completely disconnected from all
power sources before performing inspection.
5.2.1 Override of Door / Switch Mechanism
Interlock
To close the switch with the door open, the interlock
must be disengaged. To close the switch, insert the
handle into the handle casting and push upward, at the
same time push the latch that is accessible through a
slot in the handle cover inward until the handle casting
clears the interlocking bolt. (See Fig. 8) To open the
switch, reverse this procedure, making sure that the
door interlock is fully depressed.
Fig. 8
Override of Switch Interlock Safety Latch
Page 7
WARNING!
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