Chamberlain 8550 User manual

Serial Number:
Date of Purchase:
Belt Drive Garage Door Opener
The Chamberlain Group, Inc.
845 Larch Avenue
Elmhurst, Illinois 60126-1196
www.liftmaster.com
.
Write down the following information
for future reference:
NOTE: If you are installing the garage door opener on a one-piece door, visit
www.liftmaster.com for installation instructions.
Contents
Model 8550
FOR RESIDENTIAL USE ONLY
BELT DRIVE GARAGE DOOR OPENER.. 1
PREPARATION............................. 2
ASSEMBLY................................. 4
INSTALLATION ........................ 6-13
INSTALL THE DOOR CONTROL.....14-16
INSTALL THE
PROTECTOR SYSTEM®..............17-20
POWER ................................21-22
ADJUSTMENT.........................23-25
BATTERY BACKUP ...................26-27
OPERATION ...............................28
FEATURES.................................29
DOOR CONTROL .....................30-31
REMOTE CONTROLS.................32-33
TO ERASE THE MEMORY ...............33
TO OPEN THE DOOR MANUALLY ......34
MAINTENANCE ...........................34
TROUBLESHOOTING.................35-36
REPAIR PARTS .......................37-38
ACCESSORIES ............................39
WARRANTY ...............................40
■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®is connected and properly
aligned.
■Periodic checks of the garage door opener are required to ensure safe operation.
■The model number label is located on the left side panel of your garage door opener.
■This garage door opener is ONLY compatible with MyQ™and Security✚®2.0
accessories.
■DO NOT enable the Timer-To-Close feature if you are installing the garage door
opener on a one-piece door. The Timer -To-Close is to be used ONLY with
sectional doors.

2
Safety Symbol and Signal
Word Review
This garage door opener 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.
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.
Mechanical
Electrical
When you see this Signal Word on the following
pages,it will alert you to the possibility of damage
to your garage door and/or the garage door
opener if you do not comply with the cautionary
statements that accompany it. Read them
carefully.
Check the Door
1. Disable locks and remove any ropes
connected to the garage door.
2. Lift the door halfway up. Release the
door. If balanced, it should stay in
place, supported entirely by its springs.
3. Raise and lower the door to check for
binding or sticking. If your door binds,
sticks, or is out of balance, call a trained
door systems technician.
4. Check the seal on the bottom of the
door. Any gap between the floor and
the bottom of the door must not exceed
1/4 inch (6 mm). Otherwise, the safety
reversal system may not work properly.
5. The opener should be installed above
the center of the door. If there is a
torsion spring or center bearing plate
in the way of the header bracket, it may
be installed within 4 feet (1.2 m) to the
left or right of the door center. See
installing the Header Bracket section.
Torsion Spring Extension Spring
To prevent possible SERIOUSINJURYor
DEATH:
• ALWAYS call a trained door systems
technician if garage door binds, sticks, or is
out of balance. An unbalanced garage
door may not reverse when required.
• NEVER try to loosen, move or adjust
garage 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 garage door BEFORE
installation and operating garage door
opener to avoid entanglement.
To prevent damage to garage door and
opener:
• ALWAYS disable locks BEFORE installing
and operating the opener.
• ONLY operate garage door opener at
120 V, 60 Hz to avoid malfunction and
damage.
Tools Needed
2
1
3/16
7/16
1/2
5/32
5/16
5/8
9/16
1/4
7/16
Preparation

3
AB
C
J
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I
O
DE
F
H
GK
L
M
Overview/Carton Inventory
GARAGE DOOR OPENER ASSEMBLY
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B.Pulley and bracket
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G. Emergency release rope and handle
H.Rail
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NOTE: Accessories will vary depending on the garage door opener model purchased. Depending on your specific model, other accessories
may be included with your garage door opener. The instructions for these accessories will be attached to the accessory and are not included
in this manual. The images throughout this manuals are for reference and your product may look different.
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The Protector System®
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with white and white/black wire attached:
Sending Sensor (1) Receiving Sensor (1)
and Safety Sensor Brackets (2)
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Hardware
Assembly
H1 Hex Screw #8x3/8" (3)
[packed with the sprocket cover]
Installation
H2 Hex Bolt 5/16"-18 x 7/8" (4)
H3 Lag Screw 5/16"-9 x 1-5/8" (2)
H4 Lag Screw 5/16"-18 x 1-5/8" (2)
H5 Clevis Pin 5/16" x 2-3/4" (1)
H6 Clevis Pin 5/16" x 1-1/4" (1)
H7 Clevis Pin 5/16" x 1" (1)
H8 Nut 5/16"-18 (4)
H9 Lock Washer 5/16"-16 (4)
H10 Self-Threading Screw 1/4"-14 x 5/8" (2)
H11 Ring Fastener (3)
H12 Carriage Bolt 1/4"-20 x 1/2" (2)
H13 Wing Nut 1/4"-20 (2)
Door Control Hardware
H14 Screw 6AB x 1-1/4" (2)
H15 Screw 6-32 x 1" (2)
H16 Drywall Anchors (2)
H17 Insulated Staples (10)
895MAX
Remote Control
880LM
Smart Control
Panel®829LM
Garage Door
Monitor
MyQ™AND SECURITY✚®2.0
ACCESSORIES

4
To avoid possible SERIOUS INJURY to finger
from moving garage door opener:
• ALWAYS keep hand clear of sprocket while
operating opener.
• Securely attach sprocket cover BEFORE
operating.
To avoid SERIOUS damage to garage door
opener, use ONLY those bolts/fasteners
mounted in the top of the opener.
.
Mounted in the
garage door opener
HARDWARE
H1 (3)
Hex Screw
#8x3/8"
(Packed with the
sprocket cover)
NOTE: ONLY use the bolts removed from the
garage door opener.Place the garage door
opener on the packing material to prevent
scratching.
1.1 Remove the two bolts from the top of the
garage door opener.
1.2 Align the rail and the styrofoam over the
sprocket. Cut the tape from the rail, belt,
and styrofoam.
1.3 Fasten the rail with the previously removed
bolts.
1.4 Position the belt around the garage door
opener sprocket.
1.5 Attach the sprocket cover over the garage
door opener sprocket and attach with hex
screws (H1).
H1
Assembly
1Attach the rail to the garage door opener

5
2Tighten the Belt
2.1 By hand, thread the spring trolley nut on the threaded shaft until it is finger tight against
the trolley. Do not use any tools.
Spring Trolley Nut
(To motor unit)
2.2 Insert a flathead screwdriver tip into one of the nut ring slots and brace it firmly against the trolley.
Nut ring
slot
2.3 Tighten the spring trolley nut with an adjustable wrench or a 7/16” open end wrench about a quarter turn until the spring releases and snaps the nut ring against the trolley. This sets the spring to
optimum belt tension.
Nut Ring Nut Ring
AFTER RELEASE
1-1/4"
(3.18 cm)
BEFORE
1"
(2.5 cm)

6
IMPORTANT INSTALLATION INSTRUCTIONS
WARNING
To reduce the risk of SEVERE INJURY or DEATH:
1. READ AND FOLLOW ALL INSTALLATION WARNINGS AND INSTRUCTIONS.
2. Install garage door opener only on properly balanced and lubricated garage 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 opener.
4. Disable ALL locks and remove ALL ropes connected to garage door BEFORE installing
opener to avoid entanglement.
5. Install garage door opener 7 feet (2.13 m) or more above floor.
6. Mount the emergency release within reach, but at least6 feet (1.83 m) above the floor and
avoiding contact with vehicles to avoid accidental release.
7. NEVER connect garage door opener to power source until instructed to do so
8. NEVERwear watches, rings or loose clothing while installing or servicing opener. They could
be caught in garage door or opener mechanisms.
9. Install wall-mounted garage door control:
• within sight of the garage door.
• out of reach of children at minimum height of 5 feet (1.5 m).
• away from ALL moving parts of the door.
10. Place entrapment warning label on wall next to garage door control
11. Place manual release/safety reverse test label in plain view on inside of garage 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 fl at) on the floor.
13. To avoid SERIOUS PERSONAL INJURY or DEATH from electrocution, disconnectALL
electric and battery power BEFORE performing any service or maintenance.
14. DO NOT enable the Timer-to-Close functionality if operating either one-piece or swinging
garage doors. To be enabled ONLY when operating a sectional door.
NOTE:If you are installing the garage door opener on a one-piece door, visit www.liftmaster.com for installation instructions.
Installation

7
To prevent possible SERIOUS INJURY or
DEATH:
• Header bracket MUST be RIGIDLY
fastened to structural support on header
wall or ceiling, otherwise garage door might
NOT reverse when required. DO NOT
install header bracket over drywall.
• Concrete anchors MUST be used if
mounting header bracket or 2x4 into
masonry.
• NEVER try to loosen, move or adjust
garage door, springs, cables, pulleys,
brackets, or their hardware, ALL of which
are under EXTREME tension.
• ALWAYS call a trained door systems
technician if garage door binds, sticks, or is
out of balance. An unbalanced garage
door might NOT reverse when required.
• DO NOT enable the Timer-to-Close
functionality if operating either one-piece or
swinging garage doors. To be enabled
ONLY when operating a sectional door.
1Determine the header bracket location
NOTE: Ifyou are installing the garage door opener on a one-piece door, visit www.liftmaster.com for
installation instructions.
1.1 Close the door and mark the inside vertical centerline of the garage door.
1.2 Extend the line onto the header wall above the door.
You can fasten the header bracket within 4 feet (1.22 m) of the left or right of the door
center only if a torsion spring or center bearing plate is in the way; or you can attach it to
the ceiling when clearance is minimal. (It may be mounted on the wall upside down if
necessary, to gain approximately 1/2" (1 cm).
If you need to install the header bracket on a 2x4 (on wall or ceiling), use lag screws (not
provided) to securely fasten the 2x4 to structural supports.
1.3 Open your door to the highest point of travel as shown. Draw an intersecting horizontal line on
the header wall 2" (5 cm) above the high point.This height will provide travel clearance for the
top edge of the door.
NOTE: Ifthe total number of inches exceeds the height available in your garage, use the maximum
height possible, or refer to page 8 ceiling installation.
Sectional door with curved track
Header Wall
Track
2" (5 cm)
Highest Point
of Travel
Door
Header Wall
Unfinished Ceiling
Vertical Centerline
of Garage Door 2x4
2x4
Structural
Supports
Level
(Optional)
OPTIONAL
CEILING
MOUNT FOR
HEADER
BRACKET

8
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. If installing into
masonry, use concrete anchors (not provided).
HARDWARE
H3 (2)
Lag Screw
5/16"-9x1-5/8"
OPTION A WALL INSTALLATION
2.1A Center the bracket on the vertical
centerline with the bottom edge of the
bracket on the horizontal line as shown
(with the arrow pointing toward the
ceiling).
2.2A Mark the vertical set of bracket holes (do
not use the holes designated for ceiling
mount). Drill 3/16" pilot holes and fasten
the bracket securely to a structural
support with the hardware provided (H3).
OPTION B CEILING INSTALLATION
2.1B Extend the vertical centerline onto the
ceiling as shown.
2.2B Center the bracket on the vertical mark,
no more than 6" (15 cm) from the wall.
Make sure the arrow is pointing away
from the wall. The bracket can be
mounted flush against the ceiling when
clearance is minimal.
2.3B Mark the side holes. Drill 3/16" pilot holes
and fasten bracket securely to a structural
support with the hardware provided (H3).
UP
CEILING MOUNT ONLY
Wall Mount
Optional
Mounting
Holes
H3
Vertical
Centerline of
Garage Door
(Header Wall)
Header
Bracket
2x4 Structural
Support
Door Spring
(Garage Door)
Highest Point of
Garage Door
Travel
Horizontal
Line
The nail hole is for positioning
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UP
CEILING MOUNT ONLY
(Header Wall)
Ceiling Mounting Holes
(Finished Ceiling)
Vertical
Centerline of
Garage Door
Header
Bracket
6" (15 cm)
Maximum
Door Spring
(Garage Door)
H3
The nail hole is for positioning
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Installation
2 Install the Header Bracket

9
3.1 Align the rail with the header bracket.
Insert the clevis pin (H5) through the
holes in the header bracket and rail.
Secure with the ring fastener (H11).
NOTE: Use the packing material as a
protective base for the garage door opener.
H11
H5
HARDWARE
H5
Clevis Pin
5/16"x2-3/4"
H11
Ring Fastener
4Position the garage door opener
To prevent damage to garage door, rest garage
door opener rail on 2x4 placed on top section of
door.
4.1 Remove the packing material and lift the
garage door opener onto a ladder.
NOTE: A 2x4 is ideal for setting the distance
between the rail and the door. If the ladder is
not tall enough you will need help at this point.
4.2 Fully open the door and place a 2x4 (laid flat) under the rail.
NOTE: Ifthe door hits the trolley when it is raised, pull the trolley release arm down to
disconnect the inner and outer trolley. Slide the outer trolley toward the garage door opener.
The trolley can remain disconnected until instructed.
Connected Disconnected
3Attach the rail to the header bracket

10
To avoid possible SERIOUS INJURY from a
falling garage door opener, fasten it SECURELY to
structural supports of the garage. Concrete anchors MUST
be used if installing ANY brackets into masonry.
HARDWARE
H4 (2)
Lag Screw 5/16"- 18x1-5/8" H2 (2)
Hex Bolt 5/16"- 18x7/8"
H8 (2)
Nut 5/16"-18
H9 (2)
Lock Washer
5/16"-16
Hanging the garage door opener will vary
depending on your garage. Below are three
example installations. Your installation may be
different. For ALL installations the garage door
opener MUST be connected to structural
supports. The instructions illustrate one of the
examples below.
Finished Ceiling
Unfinished Ceiling
5.1 On finished ceilings, use the lag screws
(H3) to attach a support bracket (not
provided) to the structural supports
before installing the garage door opener.
Finished
Ceiling
H4
(not provided)
H4
5.2 Make sure the garage door opener is
aligned with the header bracket. Measure
the distance from each side of the garage
door opener to the support bracket.
5.3 Cut both pieces of the hanging bracket to
required lengths.
5.4 Attach the end of each hanging bracket to
the support bracket with appropriate
hardware (not provided).
(not provided)
5.5 Attach the garage door opener to the
hanging brackets with the bolts (H2), lock
washers (H9) and nuts (H8).
H2
H8
H9
5.6 Remove the 2x4 and manually close the
door. If the door hits the rail, raise the
header bracket.
Installation
5Hang the garage door opener