Adjustment Section: Pages; Travel Limit Adjustments - Chamberlain Security+ 4640 Owner's Manual

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.
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.
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 30).
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
five feet:
Increase up travel. Turn the UP limit adjustment screw
clockwise. One turn equals 2" of travel.
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 door still won't close completely, try lengthening the
door arm. (Page 26.)
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 12 and 13.
Adjustment Section: Pages 28 – 30
How and When to Adjust the Limits
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 monthly, and following all adjustments to
the travel limits. See page 30.
1 2
8
7
Right Side Panel
LIMIT ADJUSTMENT
LABEL
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 22.
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.
28
WARNING
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3
8
1 1
3 7 3
5
5
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Kg Kg
Travel Limit
Adjustment
Adjust UP Travel
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Adjust DOWN Travel
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Screws