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LiftMaster 3900 Support Question

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Question posted by lkelch on August 7th, 2011

Too Much Slack

I have installed many doors but not many jackshaft operators. I am having trouble with cable slack on the close cycle which engages the cable monitor and reverses the door. (which means it is doing what it should, I know) however after re-adjusting the cables there is now equal slack to both sides on closing which still triggers the monitor to reverse. I took a half wind out of both springs to make the door heavy thinking it would help but it does not. Any ideas?

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Related LiftMaster 3900 Manual Pages

3900PLD Manual - Page 1

... near the door after installation. ■ The door WILL NOT CLOSE unless The Protector System® and cable tension monitor are connected and properly aligned. ■ Periodic checks of the operator are required to ensure safe operation. ■ The model number label is located behind the hinged door of your operator. ■ Do NOT exceed 10 complete cycles of door operation per hour...

3900PLD Manual - Page 2

...) . . . 13 Install The Protector System 14-16 Adjustment 17-20 Program the travel limits 17 Set the force 18 Test the safety reversal system 19 Test The Protector System 19 Test cable tension monitor 20 To open door manually 20 Operation 21-25 Operation safety instructions 21 Using your door operator 21 Care of your garage door and/or the garage door operator if you...

3900PLD Manual - Page 3

... torsion bar while the door is no access door to the garage, as this page as you proceed with : • Doors that use a torsion bar, springs and a door no noticeable movement up to 180 sq. Motor unit Cable Tension Monitor Torsion Spring Drum Wall-mounted Single Access Door Button Control Station Safety Reversing Sensor Safety Reversing Gap between the side...

3900PLD Manual - Page 7

... mounted at a right angle to the torsion bar to prevent antenna from being entangled in door or operator mechanisms. 8. NEVER connect door operator to wall. 6. NEVER wear watches, rings or loose clothing while installing or servicing operator. It may not reverse when required and could be flush to power source until pilot holes align with 14-10x1...

3900PLD Manual - Page 8

...door could result in an open door falling rapidly and/or unexpectedly. • NEVER use emergency release handle to disengage door ONLY when door is CLOSED. Fasten power door lock to the outside of the garage door track with an overhand knot. Emergency Release Cable...staples to secure wire in several places. 6. INSTALLATION STEP 2 Attach the Emergency Release Rope and Handle •...

3900PLD Manual - Page 9

... for screws (pilot holes are not required for ANY slack that prevent the cable tension monitor or the cable itself from closing completely when slack is detected. 2. Attach the cable tension monitor to the drum as the operator. NOTE: Cable must be installed on the opposite side of door during normal operation. Position the cable tension monitor as required. Make sure that the roller is...

3900PLD Manual - Page 11

... of electric shock. 2. Clips slide in the outlet, reverse the plug. 4. See Programming Remote Light. This portable luminaire has a polarized plug (one way. 3. Light is required for ceiling mount and indoor applications ONLY. Light must be fully inserted. 6. NOTE: If installing remote light (operator light) on each side of an electrical outlet so...

3900PLD Manual - Page 12

... it fit outlet. To prevent possible SERIOUS INJURY or DEATH from unit. • Install a 90o conduit or flex cable adapter to the 7/8" hole. PERMANENT WIRING CONNECTION RIGHT WRONG If permanent wiring is grounded. Be sure the operator is required by your operator has a grounding type plug with ALL local electrical and building codes. •...

3900PLD Manual - Page 14

... the door is necessary to avoid drilling extra holes in masonry if repositioning is necessary. If installing in the down direction. The units must be installed inside the garage 14 Safety Reversing Sensor ... designed to full open position, and the operator lights will flash 10 times. This is closing, the door will stop and reverse to clip onto the track of the door as long as ...

3900PLD Manual - Page 16

...steadily after installation, check for an open , it receives the sender's beam. ALIGNING THE SAFETY REVERSING SENSORS &#...operator connections. • Incorrect wiring between safety reversing sensors and operator. • A broken wire. 2. If the door is closing, the door will not close. NOTE: When the invisible beam path is obstructed or misaligned while the door is already open...

3900PLD Manual - Page 17

Door MUST reverse on contact with proper operation of the door by a closing the door (Figure 3). 4. Push the door control or programmed remote control. This sets the UP (open ) position. Push and hold the black button until the door reaches the desired DOWN (closed) position. 6. This sets the DOWN (close ). Repair door first. • Incorrect adjustment of door travel limits ...

3900PLD Manual - Page 18

... with 1-1/2" high (3.8 cm) object (or 2x4 laid flat) on contact with proper operation of force required to open and close the door (DOWN). The LED will open and close (DOWN). 3. If the garage door opener cannot open (UP). 4. ADJUSTMENT STEP 2 Set the Force The force setting measures the amount of safety reversal system. • After ANY adjustments are made, the safety...

3900PLD Manual - Page 19

... TEST • With the door fully open the door. • Place the operator carton in the path of the operator. The door must reverse on the floor. 1-1/2" (3.8 cm) board (or a 2x4 laid flat) Without a properly installed safety reversing sensor, persons (particularly small children) could be SERIOUSLY INJURED or KILLED by a closing door. • Safety reversal system MUST be SERIOUSLY...

3900PLD Manual - Page 21

... can be seen clearly, it is activated (with the safety reversing sensor correctly installed and aligned) 1. NO ONE SHOULD GO UNDER A STOPPED, PARTIALLY OPENED DOOR. 6. After ANY adjustments are made by a trained door systems technician. 12. ALL repairs to disengage door ONLY when door is CLOSED. When the operator is properly adjusted and there are no effect in an...

3900PLD Manual - Page 23

... 5. The door opens and closes by itself: • Be sure that all remote control push buttons are controlled by its springs. Operator operates from the remote, but won 't work: • The door springs may be broken. The door reverses for no apparent reason: • Check the safety reversing sensor. Operate the door manually. Open and close : • Check cable tension monitor (see...

3900PLD Manual - Page 25

...6-8" (15-20 cm). • Unplug unit to reset. 9 FLASHES Cable tension monitor reversal. Installed Safety Reversing Sensor Your garage door operator is not lit on the safety reversing sensors do not light, replace the safety reversing sensors. Symptom: One or both of the Indicator lights on door control. • Inspect door control/wires for a short (staple in wire), replace as needed...

3900PLD Manual - Page 26

... authorize the purchaser or supplier of the non-rolling code transmitter to circumvent that may cause undesired operation. 26 THE REMOTE CONTROL BATTERY 3. If the safety reversing sensors are not installed or misaligned, the door will not close from a hand-held Remote Control (Not Provided) Below are instructions for up (+). To reduce risk of old...

3900PLD Manual - Page 27

...close the door even after it may authorize access by pressing the new PIN, then press Enter. The learn indicator light blinks and shuts off upon learning the remote control. If the optional remote light is known, it has expired. To change an existing, known PIN If the existing PIN is installed... your garage door operator. Press...open the door. To set a temporary PIN: 1. Press the ...

3900PLD Manual - Page 28

Press the "learn button" on . 28 Programming Remote Light (Not Provided) The garage door operator remote light will need to be programmed to program the light. 1. Activate the door using the Single Button Control Station (or hand-held remote control or keyless entry, if programmed). 3. It has learned the code and the light turns ...

3900PLD Manual - Page 30

...Brackets: (Optional) For safety reversing sensor installation onto the wall or floor. 475LM 377LM Keyless Entry with Security✚® : Enables end user to operate door operator from outside by entering a...; StandBy Power System: Provides backup power to the model 3900 door operator. Alternate Mounting Kit: This kit allows the operator to be limited to a programmable number of hours or ...