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PowerVac
5kV Vertical Lift
®
Appendix A
B. CHECKING FOR PROPER INTERLOCK AND
TRIP-FREE FUNCTIONS BEFORE LOWERING
THE BREAKER FROM THE ELEVATED POSITION.
1. STANDARD OPERATION: When the breaker
is in the fully elevated and connected position,
releasing the motor operating handle will re-
turn the positive interlock roller into the upper
"Vee" notch in the interlock switches and ener-
gizing the circuit that will charge the springs.
The breaker may now be closed.
In order to lower the breaker from the connected
position, the breaker must be opened. If the
breaker is not open, the operator can not, and
should not be able to engage the clutch or acti-
vate the motor circuit. The positive interlock
roller will remain locked and will not allow the
interlock cam plate to move vertically far enough
to activate the elevating motor.
2. MODIFICATION KIT CHECK: To test the
function of the positive interlock system and trip-
free function, the following checks should be
made:
a. With the breaker closed and in the el-
evated position, the positive interlock
roller on the breaker must remain locked
and not allow the motor handle to be
moved far enough to engage the clutch
and close the clutch switch contacts that
energize the motor circuit. There should
be 1/16" clearance between the clutch
and motor coupler, when the motor
handle is pulled forward.
b. Disconnect the elevating motor plug
from its socket.
c. Trip the breaker to the open position.
Courtesy of NationalSwitchgear.com
d. Using the manual charging, charge the
closing springs in the breaker until the
semaphore shows charged.
e. Pull back the elevating handle on the
motor so that the interlock roll is at the
dimension shown in Figure 1A. Hold it
in this position while pressing the
manual close push button on the
breaker. The main power springs must
discharge and the breaker must remain
open, as indicated by the semaphores
on the front of the breaker. This indi-
cates that the breaker contacts will not
close during raising or lowering the
breaker.
62
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