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Adjustment, Adjust the up and down travel limits, Adjustment step 1 – Chamberlain 3575S User Manual

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Without a properly installed safety reversal system, persons
(particularly small children) could be SERIOUSLY INJURED or
KILLED by 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 adequate clearance.

ADJUSTMENT STEP 1

Adjust the UP and DOWN Travel Limits

Limit adjustment settings regulate the 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.

• 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
(Adjustment Step 3, page 25).

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. 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 WHEN TO ADJUST THE LIMITS

If the door does not open completely but opens at
least five feet (1.5 m):

Increase up travel. Turn the UP limit adjustment screw

clockwise. One turn equals 3" (7.5 cm) of travel.

NOTE: To prevent the trolley from hitting the cover

protection bolt, keep a minimum distance of 2-4"
(5-10 cm) between the trolley and the bolt.

If door does not open at least 5 feet (1.5 m):

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 3" (7.5 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 21) 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 3" (7.5 cm) 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 18.

Test the door for binding: Pull the emergency release

handle. Manually open and close the door. If the door is
binding or unbalanced, call for a trained door systems
technician. If the door is balanced and not binding,
adjust the DOWN (close) force. See Adjustment Step 2.

ADJUSTMENT LABEL

Left Side Panel

Cover
Protection
Bolt

2-4"
(5-10 cm)

Limit Adjustment Screws