Craftsman 139.53975SRT - Manual (Page 28)

Adjustment Section: Pages 28 - 30
Adjustment Step 1
Adjust the UP and DOWN Limits
Do not make any limit adjustments until the
safety reversing sensors are completely
installed.
Limit adjustment settings regulate the points at
which the door will stop when moving up or down.
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.
To operate the opener, press the Door Control push
button. Run the opener through a complete travel
cycle.
• Does the door open and close completely?
• Does the 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
falls (See page 30).
Adjustment procedures are outlined below.
Read the procedures carefully before
proceeding to Adjustment Step 2. Use a
screwdriver to make limit adjustments. Run the
opener through a complete travel cycle after
each adjustment.
NOTE: Repeated operation of the opener during
adjustment procedures may cause the motor to
overheat and shut off. Simply wait 15 minutes and
try again.
Improper adjustment of the travel limits will
interfere with the proper operation of the
safety reverse system.
The door might not
reverse properly when required and could
seriously Injure or kill
someone under It Test
the safety reverse system after making all
travel and force adjustments. See page 30.
-?5-
15
2-4"
Toooy/
” Left Side Panel °
Cover
Protection
Bolt
Limit Adjustment
Screws
Adjustment Label
How and When to Adjust the Limits
• If the door does not open completely, but
opens at least iwe feet:
Increase up travel. Turn the UP limit adjustment
screw clockwise. One turn equals 2" of travel.
NOTE: To prevent the trolley from hitting the cover
protection bolt, keep a minimum distance of 2-4”
between the trolley and the bolt.
• If door does not open at least 5 feet:
Adjust the UP (open) force as explained in
Adjustment Step 2.
• If the door does not close completely:
Increase down travel. Turn the DOWN limit
adjustment screw counterclockwise. One turn
equals 2" of travel.
If the door still won't close completely and the trolley
bumps into the trolley stop bolt (see page 4 or 5), tty
lengthening the door arm (see page 26) and
decreasing the down limit.
• If the opener reverses in fully closed position:
Decrease down travel. Turn the DOWN limit
adjustment screw clockwise. One turn equals 2" of
travel.
• If the door reverses when closing and there is
no visible interference to travel cycle:
If the opener lights are flashing, the Safety Reversing
Sensors are either not installed, misaligned, or
obstructed. See Troubleshooting, page 23,
Test the door for binding: Pull the emergency release
handle. Manually open and close the door. If the door
is binding, call for garage door service. If the door is
not binding or unbalanced, adjust the DOWN (close)
force. See Adjustment Step 2.
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