S&C Instruction Sheet 761-505 21
Installation
Checking Operation
STEP 23. Open and close the switch slowly through its
full travel.
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 that the following condi tions exist:
(a) With the operating handle as far as it will go in
the closing direction, both main contacts of each
switch pole are fully closed with the blade within
⅛-inch (3 mm) of the stop on the termi nal base
casting. See Figure 25.
(b) Each switch-pole toggle mechanism should lie
against its closed stop. See Figure26.
(c) If none of the switch poles are fully closed, the
effective length of the vertical operating pipe
may need to be increased.
Loosen the vertical operating-pipe clamp bolt
on the lowest rod guide (or bell-crank) coupling.
See Figure 27.
Move the operating handle approximately
20 degrees from the Closed position and then
torque the rod guide (or bell-crank) clamp bolt.
Then, move the operating handle to the fully
Closed position and recheck for adherence to
the conditions described above.
Figure 25. Check that the blade is fully closed and within ⅛-inch
(3 mm) of the stop on the terminal base casting
Figure 26. Verifying the toggle mechanism lies against the
closed stop.
≤
⅛-inches
(3 mm)
Main contacts fully closed
Closed stop
Figure 27. Increasing the effective length of the vertical
operating pipe.
Lowest section of
vertical operating pipe
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