GE Industrial Solutions PowerVac 5kV VL PV VL 4.16-250-0 - Manual (Page 27)

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With the breaker closed and
charged and the closing spring
gagged for safety (Chapter 7-3),
verify that each phase has suf-
ficient spring wipe. If more
then two red lines are showing
the breaker wipe is sufficient.
The minimum wipe, 0.050”, has
been reached when the white
space between the second and
third line is no longer visible
above the wipe plate. Adjust-
ment is not required until wipe
is 0.050 inch or less.
If adjustment is required see
WIPE ADJUSTMENT in ME-
CHANICAL ADJUSTMENTS
Chapter 11-2.
8-3 Contact Gap
The method of measuring the contact gap is as
follows: First with the breaker in the open posi-
tion, the closing springs charged, and the clos-
ing spring gag tool installed for safety (Chapter
7-3), apply a piece of masking tape to the sur-
face of the operating rod insulator as shown in
Figure 24. Using a reference block, make a mark
on the tape near the top on all three poles. The
reference block should be 6 23/32” long, if the
breaker mechanism has been removed from the
breaker truck, or X” if verifying the gap with the
element installed in the truck. It is also advis-
able to put a reference mark on the tape to iden-
tify to which pole the tape is applied.
Remove the closing spring gag tool and close
the breaker. Using the same procedure as above,
re-mark the tape. This new mark will be near
the bottom of the tape. Trip the breaker, remove
the tapes and re-apply them to a flat surface.
Measure the distance between the two lines. A
caliper will give an accurate reading of the con-
tact gap.
Dimension B: The gaps must be between 0.480”
PowerVac ® 5kV Vertical Lift
Chapter 8. Dimensional Checks
1 Operating rod insulator
2 Operating rod nut
3 Wipe indicator
and 0.600” for all three phases.
A properly adjusted breaker will generally have
less gap and wipe on the center pole than on
the outside poles. Due to the fact that the outer
phases are directly driven by the secondary drive
cranks by the primary cross shaft and the cen-
ter phase is driven by the secondary drive cranks
by the secondary cross shaft, the center phase
tends to lag the outer phase during opening and
closing. See Chapter 5-4 and 5-5 for a thorough
description on opening and closing. It is im-
portant that the three phases do not open or
close more than two milliseconds apart from
each other. In general the center phase will need
a gap of 0.020” less than the outer phases to
prevent any phase stagger. If the center phase
measures 0.550” nominally then the outer phase
should be approximately 0.570”.
3
4
5
1
2
Figure 25. Wipe indicator check and wipe measurement -
rear view.
4 Wipe Indicator adjustment nut
5 Actual Wipe measurement