Adjustment; Adjustthe Force - Craftsman 139.53903DM Owner's Manual

ADJUSTMENT STEP 2
Adjustthe Force
Force adjustment controls are located on either the right or back
panel of the motor unit. Force adjustment settings regulatethe
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 about3/4 of a
completeturn. Do not force controlsbeyondthat 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 WHENTO ADJUSTTHE FORCES
1. Testthe DOWN (close) 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. SeeAdjustment
Step 3, page 29. If the door is hardto hold or doesn't
reverse, DECREASE DOWN(close) force by turning
the control counterclockwise. Make small adjustments until
the door reversesnormally. After each adjustment, run the
opener through a complete cycle.
• If the door reverses duringthe down (close) cycle and the
opener lights aren't flashing, 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. 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
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.
olf 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 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" high (3.8 cm) object (or 2x4 laid flat) on floor.
Model 53901DM
LBaC i Panel
Force Adjustment
Controls
J
Models 53903DM
53905DM
Force Adjustment
Controls
Right Panel
_ 7'o 0 0
ADJUSTMENT LABEL
Open Force
Close Force
28