S&C Instruction Sheet 761-505
25
Installation
STEP 24.
Open and close the switch
slowly
several times.
CAUTION
The switch should be opened and closed
slowly only when checking for alignment
and complete closure.
When opening or closing the switch in
service,
do not
slow down or stop part way.
Arcing can occur if the switch is partially
open or partially closed.
Check the operation of each switch pole. The
following conditions must be met:
(a) As the blade assembly moves in the
closing
direction, each blade-closing cam must make
positive engagement with its respective inter-
rupter closing lever. See Figure 32.
(b) With the blade assembly in the fully
Closed
position, verify the minimum clearance between
each blade shunt contact and its respective
interrupter housing. See Figure 33. The shunt
contacts may be bent as required to provide this
clearance.
(c) Also, when the blade is in the fully
Closed
position, each blade-closing cam must overlap
its respective interrupter closing lever to pre vent
inadvertent opening of the interrupter, and
clearance between the blade closing cam and its
respective interrupter closing lever must be
within the limit shown.
Figure 33. The blade assembly in the fully Closed position.
Figure 32. The blade assembly moving in the closing direction.
Blade shunt
contact
Interrupter
housing
⅜
-inch (10-mm)
minimum
1⁄16
-inch (2-mm) min,
5⁄16
-inch (8-mm) max
Positive
engagement
Blade-closing cam
Interrupter closing lever
Overlap
