10
Replacement is the reverse of procedure 3.3. Note that the crank arm must be positioned
flush with the end of the motor shaft, and the set screw opposite the flat surface on the
shaft.
3:4 MECHANICAL LIMIT SWITCH ADJUSTMENT
The limit switches controlling the normal and emergency positions of the main
switches, have been factory set to a clearance of 0.020” between the face of the
switch and the limit switch cam, to ensure continued reliable operation. Should it
become necessary to adjust this gap, in the event of replacing a limit switch for
example, the following procedure is recommended (see diagram page 12):
a) Electrically isolate the transfer switch from all power sources. Loosen the
pivot screw and clamp screw to enable the limit switch to rotate about the
pivot screw.
b) Open the cover on the operating arm and remove the pin slider to allow the
limit switch cam to be rotated manually.
c) Insert a 0.020” feeler gauge between the face of the limit switch cam and
the operating plunger of the switch. Rotate the limit switch about the pivot
screw to establish the 0.020” clearance. Tighten the clamp screw and pivot
screw.
d) Rotate the limit switch cam by hand to check the switch operation and
readjust if necessary
e) Replace the pin slider and close the cover.
Manual for AST3225
Automatic
Transfer Switch
