Chamberlain LJ8900W User manual

For Light Duty Commercial Use
Install On Sectional Doors With
Torsion Assemblies Only
NOT FOR RESIDENTIAL USE
Light-Duty Jackshaft Operator
for Sectional Doors
Model LJ8900W
LiftMaster
300 Windsor Drive
Oak Brook, IL 60523
• Please read this manual and the enclosed safety materials carefully!
• 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 is located on the front cover of the operator.
• DO NOT exceed 10 complete cycles of door operation per hour.
This product is to be installed and serviced by a trained door systems technician only.
This product may require adjustments to door springs and/or track configurations. This
product is not intended for use on low headroom tracks with outside pickup drum or
doors utilizing extension springs.
2 YEAR WARRANTY
After Installation, Please Leave with Customer
Register your door operator to receive updates and offers from LiftMaster
Take a photo of the
camera icon including
the points ( ).
Send it in by texting
the photo to 71403
(US) or visit
www.liftmaster.photo
(Global)
SM

2
Introduction
When you see these Safety Symbols and Signal Words on the following pages, they
will alert you to the possibility of serious injury or death if you do not comply with the
warnings that accompany them. The hazard may come from something mechanical or
from electric shock. Read the warnings carefully.
When you see this Signal Word on the following pages, it will alert you to the possibility
of damage to your door and/or the door operator if you do not comply with the cautionary
statements that accompany it. Read them carefully.
Mechanical
Electrical
Safety Symbol and Signal Word Review
This door operator has been designed and tested to offer safe service provided it is installed, operated, maintained and tested in strict
accordance with the instructions and warnings contained in this manual.
Table of Contents
Introduction 2
Safety Symbol and Signal Word Review ...2
Planning....................................................3
Preparing Your Door.................................4
Tools Needed............................................4
Carton Inventory .......................................5
Hardware ..................................................5
Additional Items You May Need................5
Assembly 6
Attach the Collar to the Door Operator......6
Attach Mounting Bracket to
Door Operator...........................................7
Installation 7
Position and Mount the Door Operator .....8
Attach the Emergency Release Rope
and Handle................................................9
Install the Automatic Door
Lock (Not Provided)..................................9
Attach the Cable Tension Monitor
(Required)...............................................10
Install the Single Button
Control Station........................................11
Install the Protector System....................12
Install the Light Curtain (Not Provided)...15
Connect Power........................................16
Install the Battery
Backup (Not Provided)............................18
Adjustments 19
Program the Travel .................................19
Test the Safety Reversal System.............20
Test the Protector System.......................20
Test Cable Tension Monitor ....................21
Test Automatic door lock........................21
To Open the Door Manually ....................21
Operation 22
Using Your Door Operator ......................23
Programming 24
Remote Control (Not Provided)...............24
To Erase the Memory..............................24
Maintenance 25
Care of Your Door Operator ....................25
Troubleshooting 26
Diagnostic Chart .....................................26
Additional Troubleshooting.....................27
Repair Parts 29
Installation Parts.....................................29
Door Operator Parts................................29
Accessories 30
Contact Information 30
WARNING: This product can expose you to chemicals including lead, which are known to the State of California to cause
cancer or birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov

3
Planning
Survey your area to see if any of the conditions below apply to your installation.
Depending on your requirements, additional materials may be required.
THIS DOOR OPERATOR IS COMPATIBLE WITH:
• Doors that use a torsion bar and springs. The torsion bar must be 1" (2.5 cm)
diameter. NOT compatible with reverse wound drums.
• 4-6" (10-15 cm) drums, not to be used on tapered drums over 6" (15 cm).
• High lift (up to 54" (137.2 cm) high) and standard lift sectional doors up to 14 ft.
(4.3 m) high.
• Doors up to 18 ft. (5.5 m) wide.
• Doors up to 180 sq. ft. (16.7 sq. m).
Review or inspect proposed installation area. The door operator can be installed on the left
or right side of door. Select the side that meets the requirements listed below.
a. Must have minimum of 2.5" (6.4 cm)
between the wall and the center of the
torsion bar.
b. Must have minimum of 3" (7.6 cm)
between the ceiling and the center of
torsion bar.
c. Must have minimum of 8.5" (21.6cm)
between the side wall (or obstruction)
and the end of torsion bar.
d. The torsion bar must extend at least
1.5" (3.81 cm) past the bearing.
This may vary depending on your
installation requirements.
e. An electric outlet is required within
6ft. (1.83 m) of the installation area.
If outlet does not exist, contact a
qualified electrician.
f. Depending upon building
construction, extension brackets or
wood blocks may be needed to install
safety reversing sensors and cable
tension monitor.
g. Alternate floor mounting of the
safety reversing sensors will require
hardware (not provided).
h. Any gap between the floor and the
bottom of the door must not exceed
1/4" (6 mm), otherwise the safety
reversing sensors may not work
properly.
Introduction
NOTE: Inspect the torsion bar while the
door is raised and lowered. It is important
that there is no noticeable movement up
and down or left and right. If the movement
is not corrected, the life of the door
operator will be greatly reduced.
a
b
h
c
d
e
f
g
Torsion
bar
2.5"
(6.4 cm)
3"
(7.6 cm)
Wall or
obstruction
Torsion bar
8.5"
(21.6cm)
Safety
reversing
sensor
MyQ®LED
Remote Light
(Not provided)
Automatic
door lock
(Not
provided)
Door spring

4
Introduction
Preparing Your Door
BEFORE YOU BEGIN:
• Disable locks.
• Remove any ropes connected to the
door.
Complete the following test to make sure
the door is balanced and is not sticking or
binding:
1. Lift the door halfway up. Release
the door. If balanced, it should stay
in place, supported entirely by its
springs.
2. Raise and lower the door to check for
binding or sticking.
3. Doors heavier than 650 lbs. should
NOT open or fall rapidly.
If your door binds, sticks, or is out of
balance, call a trained door systems
technician.
4. Verify equal cable tension on each
side of door. Cable tension should
remain equal during the entire travel
of the door.
To prevent damage to door and operator:
• ALWAYS disable locks BEFORE installing and operating the operator.
• ONLY operate door operator at 120V, 60Hz to avoid malfunction and damage.
• DO NOT exceed 10 complete cycles of door operation per hour.
To prevent possible SERIOUS INJURY or DEATH:
• ALWAYS call a trained door systems technician if door binds, sticks, or is out of
balance. An unbalanced door may NOT reverse when required.
• NEVER try to loosen, move or adjust door, door springs, cables, pulleys, brackets
or their hardware, ALL of which are under EXTREME tension.
• Disable ALL locks and remove ALL ropes connected to door BEFORE installing
and operating door operator to avoid entanglement.
Tools Needed
During assembly, installation and adjustment of the door operator, instructions will call for hand tools as illustrated below.
Sectional Door
SPECIFICATIONS
Volts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .120 Vac - 60 Hz, ONLY
Current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.5 AMP
Light Duty Commercial Use Rated Load . . . . . . . . . . . . . . . . . . . . . . . 385 in. lb./sec.
LED Light (Not Provided) Current. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.2 AMPS
Pliers
Wire Cutters
Claw Hammer
Screwdriver
Adjustable End Wrench
1/4", 5/16", and 3/8" Sockets
and Wrench with 6" Extension
Drill Tape Measure
Stepladder
Pencil
5/32", 3/16", 5/16"
and 3/4" Drill Bits
Level

5
Carton Inventory
Introduction
2 Conductor Bell
Wire White and
White/Red
Door Operator
Cable Tension Monitor
with 2-Conductor
Green/White Bell Wires
Mounting
Bracket
Collar with
Set Screws
Safety Reversing
Sensor Bracket (2)
The Protector System (2) Safety
Reversing Sensors (1 Sending
Sensor and 1 Receiving Sensor)
with 2-Conductor White and
White/Black Bell Wire attached
Safety Labels
and Literature
Hardware
Your door operator is packaged in one carton which contains the motor unit and the parts illustrated below. If anything is missing,
carefully check the packing material.
Single Button
Control Station
Screw #10-32 (2)
Screw 14-10x2" (4)
Handle
Rope
Screw 1/4"-20x1/2" (2)
Carriage Bolt 1/4"-20x1/2" (2)
Wing Nut 1/4"-20 (2)
Additional Items You May Need
Extension brackets (Model 041A5281-1)
or wood blocks: Depending upon building
construction, extension brackets or wood
blocks may be needed to install the safety
reversing sensor.
Fastening hardware: Alternate floor
mounting of the safety reversing sensor
will require hardware not provided.
90˚ connector for cable conduit or flex
cable adapter: Required for permanent
wiring.
Battery Backup (Model 485LM): Provides
backup power to the door operator.
Automatic door lock (Model 841LM): The
automatic door lock is used to prevent the
door from being manually opened once the
door is fully closed.

6
Set
Screws
Collar
Motor
Shaft
To avoid installation difficulties, do not run the door operator until instructed to
doso.
The door operator can be installed on either side of the door (see Planning section
page3). The illustrations shown are for installation on the left side.
1. Loosen the set screws.
2. Attach collar to the door operator motor shaft. The side of the collar with the larger
hole should be placed on the motor shaft. Ensure that the collar is seated all the way
on motor shaft until stop is reached.
3. Position the collar so the screws are facing out and are accessible when attached to
the torsion bar.
4. Securely tighten the 2 square head set screws closest to the motor shaft by turning
the screws 1/4 - 1/2 turn after making contact with the motor shaft.
Attach the Collar to the Door Operator
Assembly
1
To prevent possible SERIOUS INJURY
or DEATH, the collar MUST be properly
tightened. The door may NOT reverse
correctly or limits may be lost due to
collar slip.

7
Installation
IMPORTANT INSTALLATION INSTRUCTIONS
To reduce the risk of SEVERE INJURY or
DEATH:
1. READ AND FOLLOW ALL INSTALLATION WARNINGS
AND INSTRUCTIONS.
2. Install door operator ONLY on properly balanced and
lubricated door. An improperly balanced door may
NOT reverse when required and could result in SEVERE
INJURY or DEATH.
3. ALL repairs to cables, spring assemblies and other
hardware MUST be made by a trained door systems
technician BEFORE installing operator.
4. Disable ALL locks and remove ALL ropes connected to
door BEFORE installing operator to avoid entanglement.
5. Where possible, install the door operator 7 feet (2.13m)
or more above the floor.
6. Mount the emergency release within reach, but at least
6feet (1.83 m) above the floor and avoiding contact
with vehicles to avoid accidental release.
7. NEVER connect door operator to power source until
instructed to do so.
8. NEVER wear watches, rings or loose clothing while
installing or servicing operator. They could be caught in
door or operator mechanisms.
9. Install wall-mounted door control:
• within sight of the door.
• out of reach of small children at a minimum height
of 5 feet (1.5 m) above floors, landings, steps or
any other adjacent walking surface.
• away from ALL moving parts of the door.
10. Install the Emergency Release Marking. Attach the
marking on or next to the emergency release. Install the
Entrapment Warning Placard next to the door control in
a prominent location.
11. Place emergency release/safety reverse test label in plain
view on inside of door.
12. Upon completion of installation, test safety reversal
system. Door MUST reverse on contact with a 1-1/2"
(3.8 cm) high object (or a 2x4 laid flat) on the floor.
Attach Mounting Bracket to Door Operator
2
1. Loosely attach slotted side of mounting bracket to the same side of the door
operator as the collar, using screws provided.
NOTE: Do not tighten screws until instructed.
Socket Wrench
Assembly
HARDWARE
Screw
#10-32 (2)

8
Set screws
(Torsion bar)
Bearing
Plate
Collar
Torsion Bar
.25" (.6 cm) min.
space between
bearing and
collar
Mounting Bracket
Screws 14-10 x 2"
Installation
HARDWARE
Position and Mount the Door Operator
1
NOTE: For additional mounting options refer to the accessories page.
1. Close the door completely.
2. Slide the door operator onto the end of the torsion bar. If the torsion bar is too long
or damaged, you may need to cut the torsion bar.
Ensure the collar does NOT touch the bearing.
3. Use a level to position and vertically align the door operator. Verify the mounting
bracket is located on a solid surface such as wood, concrete or door/flag bracket. If
installing on drywall, the mounting bracket MUST be attached to a stud.
4. When the door operator is properly aligned, mark the mounting bracket holes. If
necessary, tighten collar screws on the torsion bar to hold door operator in place
while marking holes.
NOTE: The door operator does not have to be flush to wall.
5. Remove the door operator from torsion bar. Drill 3/16" pilot holes at the marked
locations. Drill through metal door rail plates if necessary.
6. Slide the door operator back onto the torsion bar until pilot holes align with bracket.
7. Tighten the 2 square head set screws on the torsion bar. For a hollow torsion bar,
tighten screws 3/4 - 1 full turn after making contact with the bar. For a solid shaft
torsion bar, tighten screws 1/4 - no more than 1/2 turn after making contact with
the shaft. If installing on a keyed torsion bar, DO NOT tighten the screws into the
keyway.
8. Secure the mounting bracket to the wall and to the door operator. Use the 14-10x2"
screws to secure the mounting bracket to the wall.
To prevent possible SERIOUS INJURY
or DEATH:
• Concrete anchors MUST be used if
mounting bracket into masonry.
• NEVER try to loosen, move or
adjust door, springs, cables,
pulleys, brackets or their hardware,
ALL of which are under EXTREME
tension.
• ALWAYS call a trained door
systems technician if door binds,
sticks or is out of balance. An
unbalanced door might NOT
reverse when required.
• Operator MUST be mounted at a
right angle to the torsion bar to
avoid premature wear on the collar.
Screw
14-10 x 2" (2)

9
10 feet (3.05 m)
max.
3" (7.6 cm)
Door Track
Roller
Lock
Template
Attach the Emergency Release Rope and Handle
Install the Automatic Door Lock (Not Provided)
2
3
1. Insert one end of the emergency release rope through the handle. Make sure that
“NOTICE” is right side up. Secure with an overhand knot at least 1" (2.5 cm) from
the end of the rope to prevent slipping.
2. Insert the other end of the emergency release rope through the hole in the trolley
release arm. Mount the emergency release within reach, but at least 6 feet (1.83 m)
above floor, avoiding contact with vehicles to prevent accidental release and secure
with an overhand knot.
NOTE: If it is necessary to cut the rope, heat seal the cut end with a match or lighter to
prevent unraveling.
NOTE: Older model 24 V door locks are
incompatible.
1. The lock must be mounted within
10 ft. (3.05m) of door operator If
possible, mount on same side as door
operator. The third roller from the
bottom is ideal for most installations.
2. Ensure rail surface is clean and attach
the lock template to the track so that
the bolt hole is approximately 3"
(7.6cm) from the center of a door
roller.
3. Drill holes as marked on the template.
4. Fasten automatic door lock to
the outside of the door track with
hardware provided.
5. Run bell wire up wall to door
operator. Use insulated staples to
secure wire in several places. Insert
wire through the bottom of the door
operator.
6. Plug the connector into either plug in
the door operator.
A secondary door lock can be installed on
the opposite side of the door following the
instructions above.
Installation
The automatic door lock (model 841LM) is used to prevent the door from being
manually opened once the door is fully closed, see Accessories page 30.
Door Operator
Emergency
Release Cable
Overhand
Knot
Overhand
Knot
Emergency
Release Handle
To prevent possible SERIOUS INJURY
or DEATH from a falling door:
• If possible, use emergency release
handle to disengage door ONLY when
door is CLOSED. Weak or broken
springs or unbalanced door could
result in an open door falling rapidly
and/or unexpectedly.
• NEVER use emergency release handle
unless doorway is clear of persons
and obstructions.
HARDWARE
Screw
1/4"-20x1/2" (2)
Rope
Handle
HARDWARE
1
2
3
4
5
6

10
HARDWARE
Attach the Cable Tension Monitor (Required)
4
NOTE: The cable tension monitor is shipped for left side installation. It is recommended
that the cable tension monitor be installed on the same side of the door as the door
operator. For right side installation, remove the snap-ring holding the roller in place and
reassemble it on the opposite side of the cable tension monitor.
1. Make sure the door cable is approximately 3/4" (19 mm) from the mounting surface.
Door adjustments or shimming may be required to achieve proper depth for the door
cable.
2. Position the cable tension monitor so the roller is 2"-6" from the drum and the roller
extends 1/8"-1/4" past the cable. Make sure cable tension monitor is located over a
wood support member and the roller is free from any obstructions.
NOTE: There must be no obstructions in the installation area that prevent the cable
tension monitor from closing completely when slack is detected.
3. Mark and drill 3/16" pilot holes for screws (pilot holes are not required for anchors).
4. Attach the cable tension monitor to the wall using the hardware provided. Make sure
that the roller is on top of the cable.
5. Run bell wire to door operator. Use insulated staples to secure wire.
6. Connect bell wire to the green quick-connect terminals on the door operator (polarity
is not important).
NOTE: Cable must have tension through entire door travel. Make sure there is no
slack in cable on opposite side of door during normal operation. If slack occurs
during door travel, adjust cables as required.
A second cable tension monitor may be installed for additional security. When two cable
tension monitors are installed, the door will not move in the down direction or will reverse
if one of the monitors detects slack or is disconnected.
If one of the cable tension monitors is removed, unplug both monitors from the operator.
Then plug in the monitor you wish to use and unplug and plug in the operator three times
to relearn the monitor to the operator.
Drum
Cable
To insert or
release wire,
push in tab with
screwdriver tip
(To cable tension monitor)
(To door operator)
WHT/
GRN
Wall
2"-6"
(5-15 cm)
Approx. 3/4" (19 mm)
Cable
Tension
Monitor
Cable Tension
Monitor Roller
1/8"-1/4"
(3-6 mm)
Installation
The cable tension monitor MUST be
connected and properly installed before
the door operator will move in the down
direction.
The cable tension monitor detects ANY
slack that may occur in the cables and
will reverse the door, eliminating service
calls.
SIDE VIEW
Screws
#8-32x1" (2)
Drum
Cable Tension
Monitor Roller
Screw
14-10x2" (2)

11
Install door control within sight of door, out of reach of small children at a
minimum height of 5 feet (1.5 m) above floors, landings, steps or any other
adjacent walking surface, and away from ALL moving parts of door.
1. Remove the control station cover.
2. Fasten the control station to the wall at least 5' (1.5 m) above the ground. The
installation surface must be smooth and flat.
3. Select appropriate knockout and run the wires to the operator.
4. Connect wires to the control station and replace the control station cover.
5. Fasten the warning placards to the wall next to the single button control station.
NOTE: DO NOT connect the power and operate the door operator at this time. The door
will travel to the full open position but will not return to the close position until the
safety reversing sensors are connected and properly aligned. See page 12.
Install the Single Button Control Station
5
Installation
To prevent possible SERIOUS INJURY or
DEATH from electrocution:
• Be sure power is NOT connected
BEFORE installing door control.
• Connect ONLY to 24VOLT low voltage
wires.
To prevent possible SERIOUS INJURY or
DEATH from a closing door:
• Install door control within sight of door,
out of reach of children at a minimum
height of 5 feet (1.5 m) and away from
ALL moving parts of door.
• NEVER permit children to operate or
play with door control push buttons or
remote controls.
• Activate door ONLY when it can be seen
clearly, is properly adjusted and there are
no obstructions to door travel.
• ALWAYS keep door in sight until
completely closed. NEVER permit anyone
to cross path of closing door.
Red White
WHT/RED
WHT
To insert or
release wire,
push in tab with
screwdriver tip
Single Button
Control Station
132A2112-2
DO NOT EXCEED 10 DOOR OPERATIONS
PER HOUR.
FASTEN LABEL ADJACENT TO DOOR.
NE PAS FAIRE FONCTIONNER LA PORTE
PLUS DE 10 FOIS PAR HEURE.
FIXER L’ÉTIQUETTE PRÈS DE LA
PORTE.

12
The safety reversing sensor must be connected and aligned correctly before the
door will move in the down direction. This is a required safety device and cannot
be disabled. The LiftMaster Light Curtain LC36A may be installed as an optional
secondary safety device, see page 15.
IMPORTANT INFORMATION ABOUT THE SAFETY REVERSING SENSORS
When properly connected and aligned, the safety reversing sensor will detect an obstacle
in the path of its electronic beam. The sending sensor (with an amber indicator light)
transmits an invisible light beam to the receiving sensor (with a green indicator light).
If an obstruction breaks the light beam while the door is closing the door will stop and
reverse to the full open position.
The sensors must be installed inside the building so that the sending and receiving
sensors face each other across the door, no more than 6" (15 cm) above the floor. Either
can be installed on the left or right of the door as long as the sun never shines directly into
the receiving sensor lens.
The mounting brackets are designed to clip onto the track of sectional doors without
additional hardware.
If it is necessary to mount the sensors on the wall, the brackets must be securely fastened
to a solid surface such as the wall framing. Extension brackets (see accessories) are
available if needed. If installing in masonry construction, add a piece of wood at each
location to avoid drilling extra holes in masonry if repositioning is necessary.
The invisible light beam path must be unobstructed. No part of the door (door tracks,
springs, hinges, rollers or other hardware) may interrupt the beam while the door is
closing.
Invisible Light Beam
Protection Area
Safety Reversing Sensor
6" (15 cm) max. above floor Safety Reversing Sensor
6" (15 cm) max. above floor
Be sure power is NOT connected to the
door operator BEFORE installing the
safety reversing sensor.
To prevent SERIOUS INJURY or
DEATH from a closing door:
• Correctly connect and align the
safety reversing sensor. This
required safety device MUST NOT
be disabled.
• Install the safety reversing sensor
so beam is NO HIGHER than 6"
(15cm) above floor.
Installation
Install the Protector System
6
Facing the door from inside the building.

13
OPTION C: FLOOR INSTALLATION
1. Use wood blocks or extension
brackets (see Accessories) to elevate
sensor brackets so the lenses will be
no higher than 6" (15 cm) above the
floor.
2. Carefully measure and place right and
left assemblies at the same distance
out from the wall. Be sure all door
hardware obstructions are cleared.
3. Fasten to the floor with concrete
anchors as shown.
Installation
Fasten Wood Block to Wall with
Lag Screws (not provided)
Attach with Concrete Anchors
(not provided)
OPTION A: TRACK INSTALLATION
1. Slip the curved arms over the
rounded edge of each door track,
with the curved arms facing the door.
Snap into place against the side of the
track. It should lie flush, with the lip
hugging the back edge of the track, as
shown.
If your door track will not support the
bracket securely, wall installation is
recommended.
OPTION B: WALL INSTALLATION
1. Place the bracket against the wall
with curved arms facing the door. Be
sure there is enough clearance for the
sensor beam to be unobstructed.
2. If additional depth is needed, an
extension bracket (see Accessories)
or wood blocks can be used.
3. Use bracket mounting holes as a
template to locate and drill (2) 3/16"
diameter pilot holes on the wall at
each side of the door, no higher than
6" (15 cm) above the floor.
4. Attach brackets to wall with
lagscrews (notprovided).
If using extension brackets or wood blocks,
adjust right and left assemblies to the same
distance out from the mounting surface.
Make sure all door hardware obstructions
are cleared.
INSTALLING THE BRACKETS
Be sure power to the operator is disconnected. Install and align the brackets so the safety reversing sensors will face each other across
the door, with the beam no higher than 6" (15 cm) above the floor. Choose one of the following installations.
Door Track
Safety Reversing Sensor
Bracket
Safety Reversing Sensor Bracket
Lag Screws (not provided)
Safety Reversing Sensor Bracket
(Provided with Extension Bracket)
Extension Bracket (See Accessories)
Safety Reversing Sensor
Bracket
(Provided with
Extension Bracket)

14
Installation
WIRE THE SAFETY REVERSING SENSORS
1. Run the wire from both sensors to the door operator. Attach the wire to the wall and
ceiling with the staples.
2. Strip 7/16" (11 mm) of insulation from each set of wires. Separate the wires. Twist
the white wires together. Twist the white/black wires together.
3. Insert the white wires into the white terminal on the door operator. Insert the white/
black wires into the grey terminal on the door operator. To insert or remove the
wires from the terminal, push in the tab with a screwdriver tip.
MOUNTING THE SAFETY REVERSING SENSORS
1. Slide a 1/4"-20x1/2" carriage bolt head into the slot on each sensor.
2. Use wing nuts to fasten safety reversing sensors to brackets, with lenses pointing
toward each other across the door. Be sure the lens is not obstructed by a bracket
extension.
3. Finger tighten the wing nuts.
HARDWARE
Carriage Bolt
Wing Nut
Wing Nut
1/4"-20 (2)
Carriage Bolt
1/4"-20x1/2" (2)
WHT/
BLK
WHT
Bell wire
7/16
(11mm)

15
Installation
Install the Light Curtain (Not Provided)
7
The following are general instructions for a typical installation, refer to the
complete instructions included with the Light Curtain.
The plug-in power supply accessory (model 100MAPS) is required to power the
Light Curtain. LiftMaster Light Curtain (Model LC-36A) is an ancillary entrapment
protection device designed with 8 optical sensors that form 22 total invisible light
beams which create a cross-pattern or netting effect for maximum protection against
entrapment. If an obstruction breaks any light beam while the door is closing, the
operator will stop and reverse to the full open position. The Light Curtain Transmitter
must be installed facing the Light Curtain Receiver across the entrapment zone, 12"
(30.5 cm) above the primary monitored entrapment protection device. The minimum
installation width is 3 ft. (.91 m) and the maximum width is 33 ft. (10 m).
NOTE: Ensure that no part of the door, door tracks, springs, hinges, rollers, cords or
other hardware interrupts the light beam while the door is closing.
INSTALLATION
1. Fasten the mounting brackets loosely to both Light Curtains with the screws
provided.
2. Measure a minimum of 12" above the safety reversing sensors. Mark this
location. The Light Curtain must be installed above this point.
3. Hold the Light Curtain up to the desired mounting location with the cable end
pointing upward. Secure the bottom mounting bracket to the mounting surface.
The mounting brackets must be securely fastened to a solid surface such as a
wall framing.
4. Make sure the Light Curtain is level and secure the upper mounting bracket to
the mounting surface.
5. Tighten the screws to secure the Light Curtain to the mounting bracket.
6. Secure the other Light Curtain to the opposite side of the door following steps
2 - 5, making sure they are aligned.
WIRING
Transmitting Light Curtain:
• White Wire to white terminal on door operator
• Black Wire to gray terminal on door operator
Transmitting and Receiving Light Curtains:
• Brown Wire (+) to White/Black on power supply
• Blue Wire (-) to Black on power supply
Black
White
12" (30.5 cm) minimum above
the safety reversing sensor
Brown (+)
Blue (-) Black
Black/White
Plug-In Power
Supply
Transmitting Light
Curtain Receiving Light
Curtain
Light
Curtain
Nylon
nut
Mounting
bracket
Screw with
nylon washer
To prevent possible SERIOUS INJURY or
DEATH from a closing door:
• Be sure to DISCONNECT POWER to
the operator BEFORE installing the
Light Curtain.
• The door MUST be in the fully opened
or closed position BEFORE installing
the Light Curtain.
• Correctly connect and align the Light
Curtain transmitter and receiver.
• The Light Curtain is for use with
LiftMaster Commercial Doors. Use
with ANY other product voids the
warranty.
• DO NOT use this product for the
protection of dangerous machinery
or in explosive atmospheres or
radioactive environments. Use ONLY
specific and approved types of devices
for such applications.
• The Light Curtain MUST be installed
ONLY by authorized and fully trained
personnel.
• LiftMaster Monitored Entrapment
Protection devices are required in
addition to the Light Curtain. The Light
Curtain may NOT be used as the sole
entrapment protection device for ANY
entrapment zone.

16
Green
Ground
Screw Ground Wire
Black Wire
Wire Nuts
(Not Provided
White Wire
Flexible
Conduit
90˚
Connector
(Not
Provided)
Green Wire White Wire
Black Wire
BACK VIEW
Connect Power
8
Installation
OPTION B: PERMANENT WIRING
CONNECTION
If permanent wiring is required by
your local code, refer to the following
procedure.
To make a permanent connection through
the 7/8" hole in the back of the door
operator (according to local code):
1. Be sure power is NOT connected to
the door operator, and disconnect
power to circuit.
2. Remove the door operator from the
torsion bar, remove cover screws and
set the cover aside.
3. Cut the line cord 6" (15.2 cm) above
the strain relief.
4. Squeeze the strain relief and push
into motor unit, then remove the
strain relief from the line cord.
5. Install a 90° conduit (not provided)
or flex cable adapter (not provided) to
the 7/8" hole. Reinstall door operator
to torsion bar.
6. Run wires through conduit, cut to
proper length and strip insulation.
7. Strip 1/2" (1.3 cm) of insulation from
the existing black, white and green
wires.
8. Connect the line to the black wire and
neutral to the white wire with wire
nuts (not provided). Connect ground
wire to the green ground screw.
9. Properly secure wires under plastic
ties so that they do not come into
contact with moving parts.
10. Reinstall cover.
To avoid installation difficulties, do not
run the door operator at this time.
To reduce the risk of electric shock, your
door operator has a grounding type plug
with a third grounding pin. This plug will
only fit into a grounding type outlet. If the
plug doesn’t fit into the outlet you have,
contact a qualified electrician to install the
proper outlet.
There are two options for connecting
power:
OPTION A: TYPICAL WIRING
1. Plug in the door operator into a
grounded outlet.
2. DO NOT run door operator at this
time.
To prevent possible SERIOUS INJURY or DEATH from electrocution or fire:
• Be sure power is NOT connected to the operator, and disconnect power to circuit
BEFORE removing cover to establish permanent wiring connection.
• Door installation and wiring MUST be in compliance with ALL local electrical and
building codes.
• NEVER use an extension cord, 2-wire adapter or change plug in ANY way to make it
fit outlet. Be sure the operator is grounded.
RIGHT
WRONG
WRONGRIGHT

17
Receiving Sensor
Green LED
Sending Sensor
Amber LED
Installation
IF THE AMBER LED ON THE SENDING SENSOR IS NOT GLOWING:
• Make sure there is power to the door operator.
• Make sure the sensor wire is not shorted/broken.
• Make sure the sensor has been wired correctly: white wires to white terminal and
white/black wires to grey terminal.
If the receiving sensor is in direct
sunlight, switch it with sending
sensor so it is on the opposite side
of the door.
(Invisible light beam)
ENSURE THE SAFETY REVERSING SENSORS ARE ALIGNED
The door will not close if the sensors have not been installed and aligned correctly.
When the light beam is obstructed or misaligned while the door is closing, the door
will reverse. If the door is already open, it will not close. The sensors can be aligned by
loosening the wing nuts, aligning the sensors, and tightening the wing nuts.
1. Check to make sure the LEDs in both sensors are glowing steadily. The LEDs in both
sensors will glow steadily if they are aligned and wired correctly.
WHITE
GREY
IF THE GREEN LED ON THE RECEIVING SENSOR IS NOT GLOWING:
• Make sure the sensor wire is not shorted/broken.
• Make sure the sensors are aligned.

18
Install the Battery Backup (Not Provided)
9
Installation
To reduce the risk of FIRE or INJURY
to persons:
• Disconnect ALL electric and battery
power BEFORE performing ANY
service or maintenance.
• Use ONLY LiftMaster part # 485LM
for replacement battery.
• DO NOT dispose of battery in fire.
Battery may explode. Check with local
codes for disposal instructions.
ALWAYS wear protective gloves and
eye protection when changing the
battery or working around the battery
compartment.
When in Battery Backup mode, MyQ®Smartphone Control and wireless MyQ devices
will be disabled.
1. Unplug the door operator.
2. Use a Phillips head screwdriver to remove the battery cover on the door operator.
3. Partially insert the battery into the battery compartment with the terminals facing
out.
4. Connect red (+) and black (-) wires from the door operator to the corresponding
terminals on the battery.
5. Replace the battery cover.
6. Plug in the door operator.
BATTERY STATUS LED
Green LED:
All systems are normal.
• A solid green LED light indicates the battery is fully charged.
• A flashing green LED indicates the battery is being charged.
Orange LED:
The door operator has lost power and is in battery backup mode.
• A solid orange LED with beep, sounding approximately every 2 seconds, indicates
the door operator is operating on battery power.
• A flashing orange LED with beep, sounding every 30 seconds, indicates the battery
is low.
Red LED:
The door operator's 12V battery needs to be replaced.
• A solid red LED with beep, sounding every 30 seconds, indicates the 12V battery will
no longer hold a charge and needs to be replaced. Replace the battery to maintain
the battery backup feature.
NOTE: Battery does not have to be fully charged to activate the door operator.
Red wire (+)
Battery Status LED
Black wire (-)

19
While programming, the UP and DOWN buttons can be used to move the door as needed.
1. Press and hold the Adjustment Button until the UP Button begins to flash and/or a
beep is heard.
2. Press and hold the UP Button until the door is in the desired UP position.
3. Once the door is in the desired UP position press and release the Adjustment Button.
The door operator will beep and the DOWN button will flash.
4. Press and hold the DOWN Button until the door is in the desired DOWN position.
5. Once the door is in the desired DOWN position press and release the Adjustment
Button. The door operator will beep and the UP button will flash.
6. Press and release the UP Button. When the door travels to the programmed UP
position, the DOWN Button will begin to flash.
7. Press and release the DOWN Button. The door will travel to the programmed DOWN
position. Programming is complete.
If you are unable to program the travel:
• Ensure the cable tension monitor is correctly installed (see page 10).
• Check to see if the safety reversing sensors are misaligned or obstructed (refer to
page 17). When the sensors are aligned and unobstructed, cycle the door through
a complete up and down cycle using the remote control or the UP and DOWN
buttons. If you are unable to operate the door up and down, repeat the steps above.
Travel limits regulate the points at which the door will stop when moving up or down.
Program the Travel
Adjustments
Without a properly installed safety
reversal system, persons (particularly
small children) could be SERIOUSLY
INJURED or KILLED by a closing door.
• Incorrect adjustment of door travel
limits will interfere with proper
operation of safety reversal system.
• 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.
1
1 2 3
5
4
6 7
PROGRAMMING BUTTONS
UP Button
Adjustment
Button
DOWN Button
To prevent damage to vehicles, be
sure fully open door provides adequate
clearance.

20
TEST
1. 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 door.
2. Operate the door in the down direction. The door MUST reverse when it makes
contact with the board.
ADJUST
If the door stops but does not reverse:
1. Review the installation instructions provided to insure all steps were followed;
2. Repeat Program the Travel (see Adjustment Step 1);
3. Repeat the Safety Reversal test. If the test continues to fail, call a trained door
systems technician.
IMPORTANT SAFETY CHECK:
Test the Safety Reverse System after:
• Each adjustment of limits.
• Any repair to or adjustment of the door (including springs and hardware).
• Any repair to or buckling of the floor.
• Any repair to or adjustment of the operator.
Test the Safety Reversal System
Test the Protector System
1. Press the control station button to open the door.
2. Place the operator carton in the path of the door.
3. Press the control station button to close the door. The door will not move more than
an inch (2.5 cm).
The door operator will not close from a control station if the indicator light in either sensor
is off (alerting you to the fact that the sensor is misalignedor obstructed).
If the door operator closes the door when the safety reversing sensor is obstructed,
do not operate the door. Call for a trained door systems technician.
Without a properly installed safety
reversal system, persons (particularly
small children) could be SERIOUSLY
INJURED or KILLED by a closing door.
• Safety reversal system MUST be
tested every month.
• After ANY adjustments are made,
the safety reversal system MUST
be tested. Door MUST reverse on
contact with 1-1/2" (3.8 cm) high
object (or 2x4 laid flat) on the floor.
Without a properly installed safety
reversing sensor, persons (particularly
small children) could be SERIOUSLY
INJURED or KILLED by a closing door.
2
3
Safety Reversing Sensor Safety Reversing Sensor
1-1/2" (3.8 cm) board
(or a 2x4 laid flat)
Adjustments