e. o
vertrAvel
A
djuStInG
B
oltS
Six adjustable bolts (Figure 7, l) are threaded
into the horizontal connecting bar to provide
stops for each pole to prevent overstroking
the Power/Vac
®
interrupters. Each of these
bolts should be backed out of the horizontal
connecting bar two turns prior to performing
adjustments to the pull rod or to the trip latch
setting. To adjust the overtravel stop bolts,
back off locking nut (Figure 7, n) and turn
each of the six bolts (Figure 7, l) in toward the
opening stop block (Figure 7, k) until the bolt
touches the stop ring (ground and test device
is open for this adjustment). Back off ¼ to ½
turn and tighten the locking nuts (Figure 7, n)
to 20 to 25 ft-lbs.
f. W
Ipe
And
G
Ap
A
djuStMent
1) General
Wipe is the additional compression of the
preloaded wipe spring (Figure 7, i) which is
used to apply force to the closed vacuum
interrupter contacts. Proper adjustment
of the wipe springs is necessary to assure
that the vacuum interrupter contact will
stay closed against the forces which tend
to open them due to fault currents and to
supply the propelling energy required to
attain the correct opening speed needed
for a clean interruption of the current.
Gap is the distance between the two
vacuum interrupter contacts when the
ground and test device is open. Correct
adjustment of the gap assures that the
minimum required distance for current
interruption is achieved and that the
distance is not so great that mechanical
damage to the vacuum interrupter occurs.
Wipe and gap are related in such a way
that decreasing the wipe increases the gap
and increasing the wipe decreases the gap.
Therefore, these two adjustments must
be coordinated to bring both to within
required settings simultaneously.
Figure 7
Primary Contact Gap and Erosion
Indication
a
b
c
d
e
f
g
h
i
j
k
l
m
n
a. Interrupter Moveable Contact
b. Coupling Clamp
c. Socket Head Cap Screws
d. Operating Rod
e. Reference Arm
f. Hex Extension
g. Erosion Indicator Disc
h. Locknut for Operating Rod
i. Wipe Spring
j. Bell Crank
k. Opening Stop Block
l. Overtravel Adjusting Bolt
m. Horizontal Connecting Bar
n. Locknut for Overtravel
Adjustment Bolt
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18
Mechanical Checks and Adjustments
Power/Vac® Electrical Ground and Test Devices
Equipped with ML-17 Mechansim
01.4IB.50100
