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PowlVac® CDR 27kV &38kV Vacuum Circuit Breaker
IB-65020A
Maintenance
CAUTION
CAUTION
!
Do NOT allow the secondary trip prop
adjusting screw to turn while loosening the
locking nut. Failure to observe this caution
will severely damage the mechanism.
4. Manually charge the circuit breaker
main spring.
5. Manually CLOSE the circuit breaker.
6. Slowly turn the secondary trip prop
adjusting screw (Figure 26, c)
clockwise in 1/8 turn (45˚)
increments until the breaker trips
OPENS. Carefully note the rotational
position of the tool used to turn the
adjusting screw at the moment the
breaker operates. Do NOT turn the
screw any further clockwise after the
breaker operates.
7. Turn the secondary trip prop
adjusting screw (Figure 7,b)
counter-clockwise 1½ full turns from
the position noted in step 6.
8. While holding the secondary trip
prop adjusting screw from turning,
securely tighten the secondary trip
prop adjusting screw locking nut.
9. Manually charge the main closing
spring using the manual charge
handle per
Ch 4 Installation
,
d. p
lAcInG
the
c
IrcuIt
B
reAker
I
nto
S
ervIce
,
4) Mechanical Operation
Check.
10. Manually CLOSE the circuit breaker.
11. Using leaf type feeler gauges with
a total of 0.090” thickness selected,
position the feeler gauge as shown
in Figure 22.
Figure 22 Feeler Gauge
a. Trip Coil Armature
b. Feeler Gauge
a
b
12. Slowly depress the trip coil
armature (Figure 22, a) using
the manual charge handle or
screwdriver and position the tool
as shown in Figure 22. Depress the
handle until the armature contacts
the feeler gauges. The circuit
breaker should not trip.
Note:
Do NOT tilt the armature. Tilting the
armature by applying a load to the
right of the feeler gauges will produce
incorrect results.
13. Choose one of the following steps
according to the TRIP status:
i. If the circuit breaker TRIPPED
during the test performed
in step 12, increase the gap
between the trip coil armature
and the latch check operator
by bending the latch check
operator (Figure 23, d)
downwards slightly using
channel lock pliers or a small
