Powell 27PV25ASD, Manual

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40
PowlVac® ASD 27kV & 38kV Vacuum Circuit Breaker
IB-65100
Maintenance
c. Tripping System Adjustment
Prior to performing any adjustment or
maintenance procedure, all high voltage
components shall be deenergized,
disconnected by means of a visible break, and
securely grounded.
WARNING WARNING
!
To adjust the PowlVac ASD Tripping System
perform the following steps:
1. Prior to performing this adjustment
procedure, all high voltage components
shall be deenergized, disconnected by
means of visible break and securely
grounded, and ensure that the control
circuits are deenergized.
2. Remove the circuit breaker front cover.
3. Loosen the secondary trip prop
adjusting screw locking nut several full
turns.
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 22, c)
clockwise in 1/8 turn (45˚) increments
until the breaker trips OPENS. Carefully
note the rotational position of the too
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 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 .090” thickness selected,
position the feeler gauge as shown in
Figure 20.
Figure 21 Feeler Gauge
12. Slowly depress the trip coil armature
using the manual charge handle.
Position the handle as shown in
Figure 21. 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.