Chamberlain 3255M 1/2 HP, 3255-2M 1/2 HP Adjustment Step, Adjust the UP and Down Travel Limits

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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 2" (5 cm) of travel.

NOTE: To prevent the trolley from hitting the cover protection bolt, keep a minimum distance of 2-4" (5 cm - 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.

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.

Cover Protection

Bolt

2-4" (5-10 cm)

Left Side Panel

Limit Adjustment Screws

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Adjustment Label

•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 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 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 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.

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Contents For Residential Use Only Garage Door OpenerIntroduction Table of ContentsOne-Piece Door Preparing your garage doorTools needed Sectional DoorONE-PIECE Door with Track Sectional Door InstallationPlanning ONE-PIECE Door Without TrackCarton Inventory Installation HardwareBolt previously removed from motor unit Assembly StepAttach the Rail to the Motor Unit Tighten the Chain InstallationDetermine the Header Bracket Location Installation StepCeiling Header Bracket Installation Install the Header BracketWall Header Bracket Installation Attach the Rail to the Header Bracket Sectional Door or ONE-PIECE Door with Track Position the OpenerHang the Opener Standard installation only Run bell wire up wall Install the Door ControlAttach the Emergency Release Rope and Handle Install the LightElectrical Requirements Facing the door from inside the garage Install The Protector SystemImportant Information about Safety Reversing Sensor Floor installation Figure Installing the BracketsGarage door track installation preferred Wall installationAligning the Safety Reversing Sensors Mounting and Wiring the Safety Reversing SensorsTroubleshooting the Safety Reversing Wood Doors Metal, insulated or light weight factory reinforced doorsFasten the Door Bracket Sectional DoorsONE-PIECE Doors Sectional Doors only Connect Door Arm to TrolleyConnect the door arm to the trolley Adjustment procedures, FigureALL ONE-PIECE Doors Assemble the door arm, FigureIf the door does not close completely Adjustment StepAdjust the UP and Down Travel Limits If door does not open at least 5 feet 1.5 mTest the UP open force Adjust the ForceHOW and When to Adjust the Forces Test the Down close forceTest The Protector System Test the Safety Reversal SystemAdjust Important Safety CheckActivate your opener with any of the following Using Your Garage Door OpenerOperation MULTI-FUNCTION Door Control Light featureLock feature Once a Year Care of Your OpenerOnce a Month Twice a YearHaving a PROBLEM? Symptom Motor unit doesn’t operate Safety reversing sensors wire open broken or disconnectedDoor control or wire shorted Symptom LED is not lit on door controlTo Erase All Codes From Motor Unit Memory To Add or Reprogram a Hand-held Remote ControlUsing the Learn Button Using the Door Control ProgrammingTo set a temporary PIN To Add, Reprogram or Change a Keyless Entry PINTo change an existing, known PIN Installation Parts Repair PartsRail Assembly Parts Complete with Logic board Motor Unit Assembly PartsComplete with Spring washer Accessories Liftmaster Service is On Call

3255M 1/2 HP, 3245M 1/3 HP, 3255-2M 1/2 HP specifications

The Chamberlain 3255-2M, 3245M, and 3255M garage door openers stand out in the market for their reliability and superior performance. Each model offers a unique combination of power and features, catering to different needs and preferences.

The Chamberlain 3255-2M is a robust 1/2 HP opener designed for heavy residential garage doors. Its powerful motor ensures smooth and efficient operation, making it ideal for doors weighing up to 7 feet high. This model incorporates the latest in opening technology, including a durable chain drive mechanism that provides strength and longevity. One of its significant features is the incorporated MyQ technology, enabling users to control their garage door remotely through a smartphone app. This innovative feature brings convenience and peace of mind, as homeowners can check the status of the door from anywhere.

Another excellent choice is the Chamberlain 3245M, a 1/3 HP model that offers a balance of performance and affordability. It is suitable for lighter doors, providing consistent and reliable opening and closing. The 3245M model also boasts a protective cover that enhances its durability against the elements. It operates quietly thanks to its direct drive system, making it an excellent option for garages attached to living spaces. Like the 3255-2M, this model is also equipped with MyQ technology, allowing users to monitor and control their garage door from their smartphones seamlessly.

Finally, the Chamberlain 3255M, another 1/2 HP opener, offers similar features to the 3255-2M but with a focus on belt drive technology. This model is built for quieter performance, making it ideal for homes where noise is a concern. The belt drive reduces vibrations and sound, ensuring a smoother user experience. This model also comes with a battery backup system, which provides added security during power outages.

All these models emphasize safety and security, featuring auto-reverse functionality that senses obstacles and prevents the door from closing on them. The Chamberlain garage door openers are also equipped with a rolling code technology that changes the access code each time the remote is used, enhancing security against unauthorized access.

In summary, the Chamberlain 3255-2M, 3245M, and 3255M garage door openers cater to a variety of needs with their powerful motors, innovative technologies, and user-friendly features. Their reliability and performance make them an excellent investment for any homeowner.
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