Chamberlain 248735S 3/4 HP Garage Door Opener User Manual


 
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ADJUSTMENT STEP 2
Adjust the Force
Force adjustment controls are located on the right panel
of the motor unit. Force adjustment settings regulate the
amount of power required to open and close the door.
If the forces are set too light, door travel may be
interrupted by nuisance reversals in the down direction
and stops in the up direction. Weather conditions can
affect the door movement, so occasional adjustment may
be needed.
The maximum force adjustment range is about 3/4 of a
complete turn. Do not force controls beyond that point.
Turn force adjustment controls with a screwdriver.
NOTE: If anything interferes with the door’s upward travel,
it will stop. If anything interferes with the door’s downward
travel (including binding or unbalanced doors), it will
reverse.
HOW AND WHEN TO ADJUST THE FORCES
1. Test the DOWN (close) force
Grasp the door bottom when the door is about
halfway through DOWN (close) travel. The door
should reverse. Reversal halfway through down
travel does not guarantee reversal on a 1-1/2"
(3.8 cm) obstruction. See Adjustment Step 3,
page 29. If the door is hard to hold or doesn't
reverse, DECREASE the DOWN (close) force by
turning the control counterclockwise. Make small
adjustments until the door reverses normally.
After each adjustment, run the opener through a
complete cycle.
If the door reverses during the down (close) cycle
and the opener lights aren't fl ashing, INCREASE
DOWN (close) force by turning the control
clockwise. Make small adjustments until the door
completes a close cycle. After each adjustment, run
the opener through a complete travel cycle. Do not
increase the force beyond the minimum amount
required to close the door.
2. Test the UP (open) force
Grasp the door bottom when the door is about
halfway through UP (open) travel. The door should
stop. If the door is hard to hold or doesn't stop,
DECREASE UP (open) force by turning the control
counterclockwise. Make small adjustments until
the door stops easily and opens fully. After each
adjustment, run the opener through a complete
travel cycle.
If the door doesn’t open at least 5 feet (1.5 m),
INCREASE UP (open) force by turning the control
clockwise. Make small adjustments until door opens
completely. Readjust the UP limit if necessary.
After each adjustment, run the opener through a
complete travel cycle.
Without a properly installed safety reversal system,
persons (particularly small children) could be
SERIOUSLY INJURED or KILLED by a closing garage
door.
Too much force on garage door will interfere with
proper operation of safety reversal system.
NEVER increase force beyond minimum amount
required to close garage door.
NEVER use force adjustments to compensate for a
binding or sticking garage door.
If one control (force or travel limits) is adjusted, the
other control may also need adjustment.
After ANY adjustments are made, the safety
reversal system MUST be tested. Door MUST
reverse on contact with 1-1/2" high (3.8 cm) object
(or 2x4 laid fl at) on fl oor.
Force Adjustment Controls
Right Panel
FORCE ADJUSTMENT LABEL
Open Force Close Force