14
When the breaker is in the fully elevated and in
the connected position, releasing the motor
operating handle will return the positive inter-
lock roller into the upper Vee notch in the inter-
lock cam plate. The breaker positive interlock
switch will close and energize the motor charg-
ing circuit allowing the closing spring to
charge. The breaker may now be closed.
In order to lower the breaker from the connected
position, the breaker should be opened. If the
breaker has not been opened, operating the
motor elevating clutch will open the contacts
and discharge the springs.
4-5 Primary Contact Penetration
After completing the Positive Interlock and trip
free functional checks, lower the break and with-
draw it from the cell. Inspect the contact sur-
faces of both the breaker studs and the station-
ary disconnecting devices. The primary discon-
nect devices utilize silver to silver contacts to
insure against reduction of current carrying ca-
pacity due to oxidation of the contact surfaces.
These contacts are of the high pressure line
contact tube and socket design, the tube being
backed up by heavy garter springs.
1.
Each segment of the stationary discon-
necting device should make a heavy im-
pression in the contact lubricant on the
breaker studs as shown in Figure 9. Con-
tact wipe should start not less than .125"
from the top of the contact ball, although
each contact need not start at the same
location.
2.
The penetration of the breaker stud in-
side the stationary disconnecting device,
as indicated by the contact lubricant,
should be 3/4” to 7/8” as shown in Fig-
ure 9. This indicates that the breaker studs
contacted at the full pressure center of
the silver band on the stationary discon-
necting device correctly.
3.
Should the inspection of the contacts
show that the breaker is not being raised
to the proper position, readjust the up-
per stop bolts and limit switches to raise
or lower the breaker to the proper loca-
tion (See Figure 6 and 53). Lock the stop
bolts in the new position.
4.
If proper contacting cannot be attained
by the above methods, additional adjust-
ments may be necessary.
Contact the local GE Sales Office for factory
assistance.
Figure 8. Primary Contact Insertion
PowerVac
®
5kV Vertical Lift
Chapter 4. Installation
