Summary of Contents for Chamberlain LiftMaster Professional 1255-2R
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GARAGE DOOR OPENER Models 1255-2R 1/2HP For Residential Use Only Owner’s Manual ■ Please read this manual and the enclosed safety materials carefully! ■ Fasten the manual near the garage door after installation. The door WILL NOT CLOSE unless the Protector System ■...
TABLE OF CONTENTS Introduction Safety symbol and signal word review...2 Preparing your garage door ...3 Tools needed ...3 Planning ...4 Carton inventory ...5 Hardware inventory ...5 Assembly Attach the rail to the motor unit...6 Attach the chain to the sprocket...6 Tighten the chain...7 Installation Installation safety instructions ...7...
Preparing your garage door Before you begin: • Disable locks. • Remove any ropes connected to garage door. • Complete the following test to make sure your garage door is balanced and is not sticking or binding: 1. Lift the door about halfway as shown. Release the door.
Planning Identify the type and height of your garage door. Survey your garage area to see if any of the conditions below apply to your installation. Additional materials may be required. You may find it helpful to refer back to this page and the accompanying illustrations as you proceed with the installation of your opener.
Carton Inventory Your garage door opener is packaged in two cartons which contain the motor unit and all parts illustrated below. Accessories will depend on the model Door Control Button SECURITY✚ Single Button Remote Control (1) Motor Unit with Light lens 2 Conductor Bell Wire White &...
ASSEMBLY STEP 1 Attach the Rail to the Motor Unit To avoid installation difficulties, do not run the garage door opener until instructed to do so. • Remove the two washered bolts mounted in top of motor unit. • Position rail at a 45˚ angle to opener so one hole in rail and motor unit line up.
ASSEMBLY STEP 3 Tighten the Chain • Spin the inner nut and lock washer down the trolley threaded shaft, away from the trolley. • To tighten the chain, turn outer nut in the direction shown (Figure 1). • When the chain is approximately 1/2" (13 mm) above the base of the rail at its midpoint, re-tighten the inner nut to secure the adjustment.
INSTALLATION STEP 1 Determine the Header Bracket Location WARNING To prevent possible SERIOUS INJURY or DEATH: • Header bracket MUST be RIGIDLY fastened to CAUTION structural support on header wall or ceiling, otherwise garage door might not reverse when required. DO NOT install header bracket over drywall.
INSTALLATION STEP 2 Install the Header Bracket You can attach the header bracket either to the wall above the garage door, or to the ceiling. Follow the instructions which will work best for your particular requirements. Do not install the header bracket over drywall.
INSTALLATION STEP 3 Attach the T-Rail to the Header Bracket • Position the opener on the garage floor below the header bracket. Use packing material as a protective base. NOTE: If the door spring is in the way you’ll need help. Have someone hold the opener securely on a temporary support to allow Header Wall the rail to clear the spring.
INSTALLATION STEP 4 Position the Opener Follow instructions which apply to your door type as illustrated. SECTIONAL DOOR OR ONE-PIECE DOOR WITH TRACK A 2x4 laid flat is convenient for setting an ideal door-to-rail distance. • Remove foam packaging. • Raise the opener onto a stepladder. You will need help at this point if the ladder is not tall enough.
INSTALLATION STEP 5 Hang the Opener Three representative installations are shown. Yours may be different. Hanging brackets should be angled (Figure 1) to provide rigid support. On finished ceilings (Figure 2 and Figure 3), attach a sturdy metal bracket to structural supports before installing the opener.
CAUTION INSTALLATION STEP 6 Install the Door Control Locate the door control within sight of the door at a minimum height of 5 feet (1.5 m) where small children cannot reach, and away from all moving parts of the door and door hardware. 1.
INSTALLATION STEP 7 Install the Light INSTALL THE LIGHT • Install a 75 watt maximum light bulb in the socket. The light will turn ON and remain lit for approximately 4-1/2 minutes when power is connected. Then the light will turn OFF. •...
WARNING INSTALLATION STEP 9 Electrical Requirements CAUTION To avoid installation difficulties, do not run the opener at this time. To reduce the risk of electric shock, your garage door opener has a grounding type plug with a third grounding pin. This plug will only fit into a grounding type outlet.
INSTALLATION STEP 10 Install The Protector System The safety reversing sensor must be connected and aligned correctly before the garage door opener will move in the down direction. IMPORTANT INFORMATION ABOUT THE SAFETY REVERSING SENSOR When properly connected and aligned, the sensor will detect an obstacle in the path of its electronic beam.
INSTALLING THE BRACKETS Be sure power to the opener is disconnected. Install and align the brackets so the sensors will face each other across the garage door, with the beam no higher than 6" (15 cm) above the floor. They may be installed in one of three ways, as follows.
MOUNTING AND WIRING THE SAFETY SENSORS • Slide a 1/4"-20x1/2" carriage bolt head into the slot on each sensor. Use wing nuts to fasten sensors to brackets, with lenses pointing toward each other across the door. Be sure the lens is not obstructed by a bracket extension (Figure 5).
INSTALLATION STEP 11 Fasten the Door Bracket Follow instructions which apply to your door type as illustrated below or on the following page. A horizontal reinforcement brace should be long enough to be secured to two or three vertical supports. A vertical reinforcement brace should cover the height of the top panel.
ONE-PIECE DOORS Please read and comply with the warnings and reinforcement instructions on the previous page. They apply to one-piece doors also. • Center the door bracket on the top of the door, in line with the header bracket as shown. Mark either the left and right, or the top and bottom holes.
INSTALLATION STEP 12 Connect Door Arm to Trolley Follow instructions which apply to your door type as illustrated below and on the following page. SECTIONAL DOORS ONLY • Make sure garage door is fully closed. Pull the emergency release handle to disconnect the outer trolley from the inner trolley.
ALL ONE-PIECE DOORS 1. Assemble the door arm, Figure 4: • Fasten the straight and curved door arm sections together to the longest possible length (with a 2 or 3 hole overlap). • With the door closed, connect the straight door arm section to the door bracket with the 5/16"x1-1/4"...
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. •...
ADJUSTMENT STEP 2 Adjust the Force Force adjustment controls are located on the back panel of the motor unit. Force adjustment settings regulate the amount of power required to open and close the door. If the forces are set too light, door travel may be interrupted by nuisance reversals in the down direction and stops in the up direction.
ADJUSTMENT STEP 3 Test the Safety Reversal System TEST • With the door fully open, place a 1-1/2" (3.8 cm) board (or a 2x4 laid flat) on the floor, centered under the garage door. • Operate the door in the down direction. The door must reverse on striking the obstruction.
OPERATION IMPORTANT SAFETY INSTRUCTIONS To reduce the risk of SEVERE INJURY or DEATH: 1. READ AND FOLLOW ALL WARNINGS AND INSTRUCTIONS. 2. ALWAYS keep remote controls out of reach of children. NEVER permit children to operate or play with garage door control push buttons or remote controls.
Using the Wall-Mounted Door Control Press the push button to open or close the door. Press again to reverse the door during the closing cycle or to stop the door while it's opening. To Open the Door Manually WARNING To prevent possible SERIOUS INJURY or DEATH from a falling garage door: CAUTION •...
CARE OF YOUR OPENER LIMIT AND FORCE ADJUSTMENTS: Weather conditions may FORCE CONTROLS cause some minor changes in door operation requiring some re-adjustments, particularly during the first year of operation. Pages 23 and 24 refer to the LIMIT CONTROLS limit and force adjustments. Only a screwdriver is required.
HAVING A PROBLEM? 1. My door will not close and the light bulbs blink on my motor unit: The safety reversing sensor must be connected and aligned correctly before the garage door opener will move in the down direction. • Verify the safety sensors are properly installed, aligned and free of any obstructions.
Bell Wire Diagnostics Located On Motor Unit Safety Sensor Diagnostic Chart 1 FLASH Safety sensors wire open (broken or disconnected). 2 FLASHES Safety sensors wire shorted or black/white wire reversed. 3 FLASHES Door control or wire shorted. 4 FLASHES Safety Sensors slightly misaligned (dim or flashing LED).
PROGRAMMING NOTICE: If this Security ✚ ® garage door opener is operated with a non-rolling code transmitter, the technical measure in the receiver of the garage door opener, which provides security against code-theft devices, will be circumvented. The owner of the copyright in the garage door opener does not authorize the purchaser or supplier of the non-rolling code transmitter to circumvent that technical measure.
To Add, Reprogram or Change a Keyless Entry PIN NOTE: Your new Keyless Entry must be programmed to operate your garage door opener. USING THE “LEARN” BUTTON 1. Press and release the “learn” button on motor unit. The learn indicator light will glow steadily for 30 seconds.
Motor Unit Assembly Parts PART DESCRIPTION 31D380 Sprocket cover 41C4220A Gear and sprocket assy. Complete with: Spring washer, thrust washer, retaining ring, bearing plate, roll pins (2), drive gear and worm gear, helical gear w/retainer and grease 41A2817 Drive/worm gear kit w/grease, Roll pins (2) 41B4245 Line cord 143D100 End panel w/all labels...
ACCESSORIES 1702LM Outside Quick Release: Required for a garage with NO access door. Enables homeowner to open garage door manually from outside by disengaging trolley. 1708LM 8 Foot Complete Rail: To allow an 8 foot door to open fully. 1710LM 10 Foot Complete Rail: To allow a 10 foot door to open fully.
LIFTMASTER ONE-YEAR LIMITED WARRANTY The Chamberlain Group, Inc. (“Seller”) warrants to the first retail purchaser of this product, for the residence in which this product is originally installed, that it is free from defect in materials and/or workmanship for a period of one year from the date of purchase and that the motor is free from defect in materials and/or workmanship for a period of four years from the date of purchase.
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