Adjustment - Craftsman 139.53920DM Owner's Manual

ADJUSTMENT STEP 1
Adjustthe UPand DOWN TravelLimits
Limit adjustment settings regulatethe points at which the door
will stop when moving up or down.
To operate the opener, press the Door Control push bar. Run the
opener through a complete travel cycle.
• Doesthe door open and close completely?
• Doesthe door stay closed and not reverse unintentionally when
fully closed?
If your door passes both of these tests, no limit adjustments are
necessary unless the reversing test fails (Adjustment Step 3,
page 29).
Adjustment procedures are outlined below. Readthe procedures
carefully before proceedingto Adjustment Step 2. Use a
screwdriver to make limit adjustments. Runthe opener througha
completetravel cycle after each adjustment.
NOTE:Repeatedoperation of the opener during adjustment
procedures may cause the motor to overheat and shut off. Simply
wait 15 minutes and try again.
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 ANDWHENTO ADJUSTTHE LIMITS
• If the door doesnot opencompletely but opensat least five
feet (1.5 m):
Increaseup travel. Turn the UP limit adjustment screw
clockwise. One turn equals 2" (5 cm) of travel.
NOTE: Toprevent the trofley from hitting the cover protection
bolt, keep a minimum distance of 2-4"(5 cm - 10 cm) between
the trolley and the bolt.
• If door does not openat least 5 feet (1.5 m):
Adjust the UP (open) force as explained in Adjustment Step 2.
• If the door doesnot close completely:
Increasedown travel. Turn the down limit adjustment screw
counterclockwise. One turn equals 2" (5 cm) of travel.
If door still won't close completely and the trolley bumps into
the pulley bracket (page 4), try lengthening the door arm
(page 25) and decreasing the down limit.
• If the opener reversesin fully closedposition:
Decreasedown travel. Turn the down limit adjustment screw
clockwise. One turn equals 2" (5 cm) of travel.
• If the doorreverses when closingand there is no visible
interferenceto travel cycle:
If the opener lights are flashing, the Safety ReversingSensors
are either not installed, misaligned, or obstructed. See
Troubleshooting, page 22.
Test the door for binding: Pull the emergency releasehandle.
Manually open and close the door. If the door is binding or
unbalanced, call for a trained door systems technician. If the
door is balancedand not binding, adjust the DOWN(close)
force. See Adjustment Step 2.
Without a properly installed safety reversal system, persons
(particularly small children) could be SERIOUSLYINJUREDor
KILLEDby a closing garage door.
• Incorrect adjustment of garage door travel limits will interfere
with proper operation of safety reversal system.
• 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.
To prevent damage to vehicles, be sure fully open door provides
adequateclearance.
o o'_.__
Limit Adjustment Screws
ADJUSTMENT LABEL
27