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52
PowlVac® CDR 27kV & 38kV Vacuum Circuit Breaker
IB-65020A
Recommended Renewal Parts and Replacement Procedures
ae. Replace the temporary bolt with
the original hardware when the
vacuum interrupter (3) is pulled
far enough to align the bolt
holes.
af. Torque the original bolts to
50 ft.-lbs.
vi. Grasp the bell portion of the
operating pushrod (4) and tighten
it by hand onto the vacuum
interrupter (3). Hold the high
voltage regulator disc (13) with
channel lock pliers and tighten the
hex head nuts (46).
vii. Install the button head cap screws
(36).
viii. Install the bottom bus support
(7) onto the high voltage housing
(11) and align the bus support
and housing to the pencil marks.
If shims were found during
disassembly
step ix
, replace the
shims in the original positions.
Apply Lock-Tite 243 to the button
head cap screws (20) and install
them.
ix. Apply Lock-Tite 243 to the hex head
screws (23) and install and torque
the screws to 30 ft.-lbs.
x. Torque the hex nuts (39) and the hex
head cap screw (24) to 30 ft.-lbs.
xi. Install the electrostatic shield (16),
then the primary disconnecting
device (1) onto the lower bus
connector (2).
xii. Torque the primary disconnecting
device to 70 ft.-lbs. with the primary
disconnect removal tool
(Catalog # 43397H01) and reinstall
hex head cap screws (32).
xiii. Tighten the socket set screws (41).
Note:
Make certain the hardware is torqued
correctly and the parts are installed
in the same positions as they were
before being removed.
When any maintenance procedure requires
the opening or closing of the circuit breaker
or the charging of any of the stored energy
mechanism springs, exercise extreme caution
to make sure that all personnel, tools, and
other miscellaneous objects are kept well clear
of the moving parts or the charged springs.
Failure to do this may cause serious damage
or injury to the circuit breaker or personnel.
WARNING
WARNING
!
c. Verification
i. Charge and close the circuit breaker.
There should be a gap between the
flat washer (45) and the high voltage
pivot (50) of Figure 27 Vacuum
Interrupter Assembly Drawing,
Detail A.
ii. The gap between the flat washer
(45) and the high voltage pivot (50)
should be set between 0.150” and
0.188” on a new vacuum interrupter
with no operations. As the devices
are operated, the gap may decrease
over time due to erosion of the
primary contacts.
iii. If the gap needs to be increased,
hold the high voltage regulator
disc (13) with channel lock pliers,
loosen the hex head nut (46) and
turn the high voltage regulator disc
(13) counterclockwise. Retighten
the hex head nut (46) and measure
the gap again. Do not allow the
pushrod (4) to turn.
Note:
Make sure the circuit breaker is in
the open position and all springs are
discharged.
