15
Limit switch
Limit switch trigger
Limit switch plate
mounted on the chain
Figure 16. Limit switch assembly on a chain
installation
Watch the status LEDs. The point where the FCA LED
on the control panel goes out is the triggering point of
the limit switch. You need to continue moving the limit
switch plate 1-3/4 in. (45 mm) farther in the gate’s
opening direction in order to allow for braking distance.
Spot-weld or mount the limit switch plate in this
position to test the mounting.
Repeat this same procedure for the limit switch for the
gate’s closing travel using the other end of the gate leaf.
Put the gate in the closed position and use the FCC LED
as the trigger indicator. Note that each limit switch
plate must be located 1-3/4 in. (45 mm) in advance of
the limit switch trigger point to allow for smooth
braking.
To check whether the limit switches are correctly
positioned, disengage the motor with the Manual
Release lever and select the E operating mode by setting
both DIP switches 1 and 2 to
on
.
Then to test the mountings of the limit switch plates,
turn on the power and generate an input signal. The
motor will turn in the opening direction but the gate will
not move because the motor is disengaged. The motor
will run (for about 2 minutes) until the control panel
senses the limit switch plate in your test.
Note
: If the motor completes its maximum motor
run time before you test a limit switch, you will
have to reset the control panel. To reset, either
press the Reset button on the 746 MPS control
panel, or cycle the main power off and then on. The
operator will then run normally.
Move the gate by hand in the opening direction and
listen to the motor as the limit switch plate moves by the
limit switch. The motor should turn off when the gate is
2 in. from the fully opened position.
Run the same sort of test of the limit switch plate
mounting for the closing direction. If necessary, adjust
the position of either limit switch plate and test the new
mounting by manually moving the gate.
If the limit switches are functioning properly when you
manually operate the gate, engage the motor of the 746
Operator with the Manual Release lever and signal the
gate to operate in the opening and closing directions. If
it operates properly, weld the limit switches into place.
Adjusting the
Clutch Torque
A torque adjustment is incorporated in the 746
Operator. FAAC recommends that the gate should stop
when it meets with a force of approximately 33 lb (15
kg). To adjust the torque pressure, turn off the main
power. Next, hold the drive shaft (with the old-style
Manual Release lever or with a 13-mm open-end
wrench) and, using a flat-blade screwdriver, turn the
clutch adjustment screw clockwise to increase the
torque and counterclockwise to lessen the torque (see
Fig. 17). Increased torque means more force is required
to stop the gate.
Figure 17. Adjust the clutch screw to change
the torque of the 746 operator
Caution:
Do not over tighten the clutch adjustment
screw or you may damage the clutch pin.
Summary of Contents for 746 ER CAT
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