Adjustment; Adjust The Up And Down Travel Limits - Chamberlain 1356M Owner's Manual

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 29).
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.
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 AND WHEN TO ADJUST THE LIMITS
• If the door does not open completely but opens at
least 5 feet (1.5 m):
Increase up travel. Turn the UP limit adjustment screw
clockwise. One turn equals 2" (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 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 reverses in fully closed position:
Decrease down travel. Turn the down limit adjustment
screw clockwise. One turn equals 2" (5 cm) of travel.
• If the door reverses when closing and there is no
visible interference to travel cycle:
If the opener lights are fl ashing, the Safety Reversing
Sensors are either not installed, misaligned, or
obstructed. See Troubleshooting, page 22.
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.
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
fl at) on fl oor.
To prevent damage to vehicles, be sure fully open
door provides adequate clearance.
Cover Protection Bolt
2-4"
(5-10 cm)
27
LEFT SIDE PANEL
Travel Limit
Adjustment Screws
ADJUSTMENT LABEL