Chamberlain 3255-2M 1/2 HP owner manual Safety reversing sensors wire open broken or disconnected

Page 30

Bell Wire

Diagnostics

Located On

Motor Unit

 

LED or

 

Diagnostic

 

LED

 

"Learn"

Safety Reversing Sensor

Button

Installed

Safety Reversing

Sensor

Your garage door opener is programmed with self-diagnostic capabilities. The “Learn” button/diagnostic LED will flash a number of times then pause signifying it has found a potential issue. Consult Diagnostic Chart below.

Diagnostic Chart

1 FLASH

Safety reversing sensors wire open (broken or disconnected).

OR

2 FLASHES

Safety reversing sensors wire shorted or black/ white wire reversed.

3 FLASHES

Door control or wire shorted.

4 FLASHES

Safety reversing sensors slightly misaligned (dim or flashing LED).

5 FLASHES

Motor overheated or possible RPM sensor failure. Unplug to reset.

6 FLASHES

Motor Circuit Failure.

Replace Receiver

Logic Board.

Symptom: One or both of the Indicator lights on the safety reversing sensors do not glow steady.

•Inspect sensor wires for a short (staple in wire), correct wiring polarity (black/ white wires reversed), broken or disconnected wires, replace/attach

as needed.

•Disconnect all wires from back of motor unit.

•Remove sensors from brackets and shorten sensor wires to 1-2 ft. (30-60 cm) from back each of sensor.

•Reattach sending eye to motor unit using shortened wires. If sending eye indicator light glows steadily, attach the receiving eye.

•Align sensors, if the indicator lights glow replace the wires for the sensors. If the sensor indicator lights do not light, replace the safety reversing sensors.

Symptom: LED is not lit on door control.

•Inspect door control/wires for a short (staple in wire), replace as needed.

•Disconnect wires at door control, touch wires together. If motor unit activates, replace door control.

•If motor unit does not activate, disconnect door control wires from motor unit. Momentarily short across red and white terminals with jumper wire. If motor unit activates, replace door control wires.

Symptom: Sending indicator light glows steadily, receiving indicator light is dim or flashing.

•Realign receiving eye sensor, clean lens and secure brackets.

•Verify door track is firmly secured to wall and does not move.

Symptom: Motor has over heated; the motor unit does not operate or trolley is stuck on stop bolt = Motor unit hums briefly; RPM Sensor =

Short travel 6-8" (15-20 cm).

•Unplug unit to reset. Try to operate motor unit, check diagnostic code.

•If it is still flashing 5 times and motor unit moves 6-8" (15-20 cm), replace RPM sensor.

•If motor unit doesn’t operate, motor unit is overheated. Wait 30 minutes and retry. If motor unit still will not operate replace logic board.

Symptom: Motor unit doesn’t operate.

•Replace logic board because motor rarely fails.

30

Page 29 Page 31
Image 30
Page 29 Page 31
Contents Garage Door Opener For Residential Use OnlyTable of Contents IntroductionSectional Door Preparing your garage doorTools needed One-Piece DoorONE-PIECE Door Without Track Sectional Door InstallationPlanning ONE-PIECE Door with TrackInstallation Hardware Carton InventoryAssembly Step Attach the Rail to the Motor UnitBolt previously removed from motor unit Installation Tighten the ChainInstallation Step Determine the Header Bracket LocationInstall the Header Bracket Wall Header Bracket InstallationCeiling Header Bracket Installation Attach the Rail to the Header Bracket Position the Opener Sectional Door or ONE-PIECE Door with TrackHang the Opener Install the Door Control Standard installation only Run bell wire up wallInstall the Light Attach the Emergency Release Rope and HandleElectrical Requirements Install The Protector System Important Information about Safety Reversing SensorFacing the door from inside the garage Wall installation Installing the BracketsGarage door track installation preferred Floor installation FigureMounting and Wiring the Safety Reversing Sensors Troubleshooting the Safety ReversingAligning the Safety Reversing Sensors Sectional Doors Metal, insulated or light weight factory reinforced doorsFasten the Door Bracket Wood DoorsONE-PIECE Doors Connect Door Arm to Trolley Sectional Doors onlyAssemble the door arm, Figure Adjustment procedures, FigureALL ONE-PIECE Doors Connect the door arm to the trolleyIf door does not open at least 5 feet 1.5 m Adjustment StepAdjust the UP and Down Travel Limits If the door does not close completelyTest the Down close force Adjust the ForceHOW and When to Adjust the Forces Test the UP open forceImportant Safety Check Test the Safety Reversal SystemAdjust Test The Protector SystemUsing Your Garage Door Opener OperationActivate your opener with any of the following Light feature Lock feature MULTI-FUNCTION Door Control Twice a Year Care of Your OpenerOnce a Month Once a YearHaving a PROBLEM? Symptom LED is not lit on door control Safety reversing sensors wire open broken or disconnectedDoor control or wire shorted Symptom Motor unit doesn’t operateProgramming To Add or Reprogram a Hand-held Remote ControlUsing the Learn Button Using the Door Control To Erase All Codes From Motor Unit MemoryTo Add, Reprogram or Change a Keyless Entry PIN To change an existing, known PINTo set a temporary PIN Repair Parts Rail Assembly PartsInstallation Parts Motor Unit Assembly Parts Complete with Spring washerComplete with Logic board Accessories Liftmaster Service is On Call
Top Page Image Contents