LiftMaster J door operator - Manual (Page 24)

24
ADJUSTMENT
CLUTCH ADJUSTMENT
(BELT DRIVE MODEL OPERATORS)
Remove the cotter pin from the clutch nut on the clutch shaft.
Turn the clutch nut to release tension.
Re-tighten the clutch nut until there is just enough tension to
permit smooth operation of the door and to allow the clutch
to slip if the door is obstructed.
Secure the clutch nut with the cotter pin.
1
1
2
2
3
3
4
4
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4
2
3
Adjustment - Clutch adjustment
To avoid SERIOUS personal INJURY or DEATH from
electrocution:
• Disconnect electric power BEFORE performing ANY
adjustments or maintenance.
ATTENTION
AVERTISSEMENT AVERTISSEMENT
AVERTISSEMENT
WARNING
CAUTION
WARNING
WARNING WARNING
PRECAUCIÓN ADVERTENCIA
ADVERTENCIA ADVERTENCIA
AUXILIARY REVERSAL SYSTEM / RPM SENSOR
The Auxiliary Reversal System is designed to protect the door
and motorized operator. It is NOT a substitute for a safety sensing
device.
Feature: This feature utilizes the RPM sensor connected to the logic
board to detect when the clutch slips and reverses the door (clutch
must be properly adjusted). In addition, the RPM eliminates the
need for a centrifugal switch on single phase motors.
Benefit: The Auxiliary Reversal System reverses the operator upon
hitting an obstruction, preventing excessive door and operator
damage. We require the use of safety devices for primary safety
protection. By removing the centrifugal switch on single phase
motors, the leading cause of motor failures is eliminated. (Auxiliary
Reversal System not applicable on models GH and GT.)
NOTE: This feature is automatically learned and does not require
programming.
LOSE OPEN
RPM Sensor
Logic Board
1
2
3
Loosen set screws on clutch nut.
Back off clutch nut until there is very little tension on the
clutch spring.
Tighten clutch nut gradually until there is just enough tension
to permit the operator to move the door smoothly but to allow
the clutch to slip if the door is obstructed. When the clutch is
properly adjusted, it should generally be possible to stop the
door by hand during travel.
Loosen set screws of torque adjustment nut on the gear
reducer.
Back off torque nut until there is very little tension on the
belleville washers.
Tighten torque nut gradually until there is just enough tension
to permit the operator to move the door smoothly through a
complete open/close cycle, but to allow the reducer to slip if
the door is obstructed.
Re-tighten the set screw that is directly over the fl at portion
of the shaft.
(3) Set Screws
Set Screws
Torque Nut
ADJUST TORQUE LIMITER CLUTCH (MODEL GT)
MODEL GH (OPTIONAL MODIFICATION)