Chamberlain 1255-2R User Manual

The Chamberlain Group, Inc.845 Larch AvenueElmhurst, Illinois 60126-1196www.liftmaster.comGARAGE DOOR OPENERModels 1255-2R 1/2HPFor Residential Use On

Header BracketChain Pulley BracketTemporarySupportHeader WallGarageDoorClevis Pin5/16"x2-3/4"Ring FastenerHeader BracketChainPulleyBracketRa

RailDoor2x4 is used to determine the correct mounting height from ceiling.HeaderBracketTop of Door2x4 is used to determine the correct mounting height

MeasureDistanceLag Screws5/16"-18x1-7/8"Bolt 5/16"-18x7/8"Lock Washer 5/16" Nut 5/16"-18StructuralSupportsBracket(Not Pr

13To prevent possible SERIOUS INJURY or DEATH fromelectrocution:• Be sure power is not connected BEFORE installing doorcontrol.• Connect ONLY to 24 VO

14INSTALLATION STEP 8Attach the Emergency ReleaseRope and Handle• Thread one end of the rope through the hole in thetop of the red handle so “NOTICE”

15INSTALLATION STEP 9Electrical RequirementsTo avoid installation difficulties, do not run theopener at this time.To reduce the risk of electric shock

16Invisible Light BeamProtection AreaSensor Beam6" (15 cm) max.above floorSensor Beam6" (15 cm) max.above floorFacing the door from inside t

17DOOR TRACK MOUNT (RIGHT SIDE)IndicatorLightLensLip SensorBracketDoorTrackFLOOR MOUNT (RIGHT SIDE)WALL MOUNT (RIGHT SIDE)IndicatorLightSensorBracketL

18Carriage Bolt 1/4"-20x1/2"LensWing NutFigure 5Figure 6 MOUNTING AND WIRING THE SAFETY SENSORS• Slide a 1/4"-20x1/2" carriage bol

19Fiberglass, aluminum or lightweight steel garage doorsWILL REQUIRE reinforcement BEFORE installation ofdoor bracket. Contact your door manufacturer

2Introduction 2-5Safety symbol and signal word review...2Preparing your garage door ...3Tool

20Header WallVerticalCenterline ofGarage DoorFinished CeilingOptionalPlacementof DoorBracketHeaderBracketDoorBracket2x4 SupportFor a door with no expo

21INSTALLATION STEP 12Connect Door Arm to TrolleyFollow instructions which apply to your door type asillustrated below and on the following page.SECTI

22ALL ONE-PIECE DOORS1. Assemble the door arm, Figure 4:• Fasten the straight and curved door arm sectionstogether to the longest possible length (wit

23ADJUSTMENT STEP 1Adjust the UP and DOWN TravelLimitsLimit adjustment settings regulate the points at whichthe door will stop when moving up or down.

ADJUSTMENT STEP 2Adjust the ForceForce adjustment controls are located on the backpanel of the motor unit. Force adjustment settingsregulate the amoun

Without a properly installed safety reversal system,persons (particularly small children) could beSERIOUSLY INJURED or KILLED by a closing garagedoor.

OPERATION26IMPORTANT SAFETY INSTRUCTIONSTo reduce the risk of SEVERE INJURY or DEATH:Using Your Garage Door OpenerYour Security✚®opener and hand-held

To Open the Door ManuallyThe door should be fullyclosed if possible. Pull downon the emergency releasehandle and lift the doormanually. To reconnect t

CARE OF YOUR OPENERLIMIT AND FORCE ADJUSTMENTS:Weather conditions maycause some minor changesin door operation requiringsome re-adjustments,particular

29HAVING A PROBLEM?1. My door will not close and the light bulbs blinkon my motor unit: The safety reversing sensormust be connected and aligned corre

3To prevent damage to garage door and opener:• ALWAYS disable locks BEFORE installing and operatingthe opener. • ONLY operate garage door opener at 12

Bell WireSafety SensorKGKG13975139751231LED or Diagnostic LED"Learn" Button DiagnosticsLocated On Motor Unit30Installed Safety SensorYour g

*3-Button RemotesIf provided with your garage door opener, the largebutton is factory programmed to operate it. Additionalbuttons on anySecurity✚®3-Bu

1. Press and release the “learn”button on motor unit. The learnindicator light will glow steadily for30 seconds.2. Within 30 seconds, enter a fourdigi

1345 6233REPAIR PARTSRail Assembly PartsKEY PARTNO. NO. DESCRIPTION1 4A1008 Master link kit2 41A4813 Chain pulley bracket3 41A3489 Complete trolley as

342108131415161943DNUPBrownWire(Down)ContactLIMIT SWITCH ASSY.GreyWireYellowWire(Up)ContactCenter LimitContactDriveGear920161218111731567KEY PARTNO. N

35LOCKLIGHTCLOSEDOPENACCESSORIES 974LM970LM995LM1708LM41A52811702LMOutside Quick Release:Required for a garage with NOaccess door. Enables homeowner t

© 2004, The Chamberlain Group, Inc.114A2648D All Rights Reserved Printed in MexicoLIFTMASTER SERVICE ISON CALLOUR LARGE SERVICE ORGANIZATIONSPANS AMER

FINISHED CEILINGSupport bracket& fasteninghardware is required.See page 12.Slack in chain tensionis normal whengarage door is closed.HeaderWallSaf

5Your garage door opener is packaged in two cartonswhich contain the motor unit and all parts illustratedbelow. Accessories will depend on the modelpu

6ASSEMBLY STEP 1Attach the Rail to the Motor UnitTo avoid installation difficulties, do not run thegarage door opener until instructed to do so.• Remo

7LockWasherTo Tighten Outer NutInner NutTrolleyChainBase of Rail1/2" (13 mm)To TightenInner NutOuter NutMid Length of RailINSTALLATIONASSEMBLY ST

8INSTALLATION STEP 1Determine the Header BracketLocationInstallation procedures vary according to garage doortypes. Follow the instructions which appl

9INSTALLATION STEP 2Install the Header BracketYou can attach the header bracket either to the wallabove the garage door, or to the ceiling. Follow the