Chamberlain 1120E-1/2HP Owner's Manual page 23

ADJUSTMENT STEP 1
Adjust UP and DOWN Limits
Limit adjustment settings regulate the points at
which the door will stop when moving up or down.
The door will stop in the up direction if anything
interferes with door travel. The door will reverse in
the down direction if anything interferes with the
door travel (including binding or unbalanced doors).
To operate the opener, press the Door Control push
bar or 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
fails (See page 25).
Adjustment procedures are outlined below. Run the
opener through a complete travel cycle after
each adjustment.
Repeated operation of the opener during adjustment
procedures may cause the motor to overheat and
shut off. Simply wait 15 minutes and try again.
Read the procedures carefully before proceeding to
Adjustment Step 2. Use a screwdriver to make limit
adjustments.
• If the door does not open completely , but
opens at least 1.5m:
Increase up travel. Turn the UP limit adjustment
screw clockwise. One turn equals 5cm of travel.
NOTE: To prevent the trolley from hitting the cover
protection bolt, keep a minimum distance of 5cm -
10cm between the trolley and the bolt.
• If door does not open at least 1.5m:
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 pulley bracket (see page 4 or 5), try
lengthening the door arm (see page 21).
Protection
How and When to Adjust the Limits
If you have adjusted the door arm to the maximum
length and the door still will not close completely,
lower the header bracket. See Installation Step 1,
pages 13 and 14.
• If the opener reverses in fully closed position:
Decrease down travel. Turn the DOWN limit
adjustment screw clockwise. One turn equals 5cm of
travel.
• If the door reverses when closing and there is
Test the door for binding: Pull the manual 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.
23
2-4"
Cover
Bolt
Left Side
Panel
INCREASE TRAVEL
DOWN
Adjustment Label
no visible interference to travel cycle:
INCREASE TRAVEL
DOWN
UP
Limit
Adjustment
Screws
UP