S&C Instruction Sheet 719-500 19
Adjusting the Switch Operator
Adjusting the Travel-Limit Discs
The
Travel Limit
switch (coupled to the motor) that
governs the extent of output-shaft rotation in the opening
and closing directions includes six contacts operated by
cam-actuated rollers. Positioning the cams to properly
engage the rollers is facilitated by the travel-limit discs
(the upper one is the opening stroke travel-limit disc; the
lower one is the closing-stroke travel-limit disc.
Complete the following steps to adjust the travel-limit discs:
STEP 1�
Adjustment of the opening-stroke travel-limit
disc (and therefore the associated cams) is
accomplished as follows:
(a) Remove the motor-circuit fuseholder. See
Figure 3 on page 9.
(b) Place the selector handle in the
Coupled
position and manually crank the circuit-
switcher to the
Open
position.
(c) For the circuit-switcher style installed and
its number of interrupting gaps per pole-
unit, determine from Table 1 on page 18 the
indicator plate number to which the open-
ing-stroke travel-limit disc is to be rotated.
Select the indicator plate number from the
“Opening-Stroke Adjustment-Clockwise to
Open” column if the disc and output shaft
rotate in the clockwise direction to open
the circuit-switcher, or from the “Opening-
Stroke Adjustment-Counterclockwise to
Open” column if the disc and output shaft
rotate in the counterclockwise direction to
open the circuit-switcher.
(d) Grasp the handwheel and turn it to the extent
possible in a direction opposite to the direc-
tion the output shaft rotates to open the
circuit-switcher. See Figure 10 on page 18.
(e) With the handwheel held in the position
indicated above, raise the opening-stroke
travel-limit disc approximately
3/16
of an
inch (5 mm) and rotate the disc until the
arrow on its outer ring is in line with the
number on the indicator plate as specified
in Table 1. Lower the disc, make sure it is
engaged, and release the handwheel. See
Figure 10 on page 18.
STEP 2�
Adjustment of the closing-stroke travel-limit disc
(and therefore the associated cams) is accom-
plished as follows:
(a) Manually crank the circuit-switcher to the
fully
Closed
position.
(b) Grasp the handwheel and turn it to the extent
possible in a direction opposite to the direc-
tion the output shaft rotates to close the
circuit-switcher. See Figure 10 on page 18.
(c) With the handwheel held in the position
indicated above, lower the closing-stroke
travel-limit disc approximately
3/16
of an inch
(5 mm) and rotate the disc until the arrow on
the outer ring is in line with the number 5 on
the indicator plate. Raise the disc, make sure
it is engaged, and release the handwheel.
STEP 3�
After adjusting the travel-limit discs, check the
following:
(a) Place the selector handle in the
Decoupled
position.
(b) Return the manual operating handle to its
Storage
position.
(c) Reinsert the motor-circuit fuseholder.
(d) Operate the switch operator electrically to
open and to close as described in Step 4(c)
on page 17. Verify the rotation direction of
the travel-limit discs for opening and closing
corresponds with the rotation direction of
the output shaft and these directions agree
with the direction displayed in the cutaway
section on the outer ring of the travel-limit
discs.
Note:
When electrical operation is performed
under the
Decoupled
or “no load” condition,
the travel limit discs do not stop at the indicator
plate positions for which they were previously
set in Steps 1 and 2. This may be disregarded.
STEP 4�
There should always be a certain amount of
“unwind” or relaxation of the output shaft (in
