Adjustthe Force - Craftsman 139.536481DM Owner's Manual

ADJUSTMENT STEP 2
Adjustthe Force
Force adjustment controls are located on the back 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 adjustmentrange is about3/4 of a complete
turn, Do not force controlsbeyondthat point, Turnforce
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.
Without a properly installed safety reversal system, persons
(particularly small children) could be SERIOUSLYINJUREDor
KILLED by a closing garage door.
• Too much force on garage door will interfere with proper
operation of safety reversal system.
• NEVERincrease force beyond minimum amount required to
close garage door.
• NEVERuse 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"
(3.8 cm) high object (or 2x4 laid flat) on floor.
HOWANDWHENTO ADJUSTTHE FORCES
1. Testthe DOWN(c/ose) force
• Grasp the door bottom when the door is about halfway
through DOWN(close) travel. The door should reverse.
Reversalhalfway 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, decreasethe
DOWN(close) force by turning the control counterclockwise.
Make small adjustments until the door reverses normally.
After eachadjustment, run the opener through a complete
cycle.
• If the door reversesduring the down (close) cycleand the
opener lights aren't flashing, INCREASEDOWN(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. Testthe 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
hardto hold or doesn'tstop, 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'topen at least 5 feet (1.5 m), INCREASE
UP (open) force by turning the control clockwise. Make small
adjustments until door opens completely. Readjustthe UP
limit if necessary.After each adjustment, run the opener
through a complete travel cycle.
Force Adjustment
Controls
ADJUSTMENT LABEL
Open Force Close Force
28