Chamberlain Security+ 3950 User manual

Owner’s Manual
■Please read this manual and the enclosed safety materials carefully!
■The door WILL NOT CLOSE unless The Protector System®is 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.
■DO NOT use with sectional type doors.
■This manual is to be left with the property owner.
DOOR OPERATOR
Model 3950
For Light Duty Commercial Use
The Chamberlain Group, Inc.
845 Larch Avenue
Elmhurst, Illinois 60126-1196
www.liftmaster.com
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Serial #
(Located on electrical box cover)
Installation Date
2 YEAR WARRANTY

2
INTRODUCTION
Safety Symbol Review and Signal Word Review
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.
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.
Mechanical
Electrical
Introduction 2-4
Safety symbol review and signal word review . . . . . . . . . . . . . . . 2
Preparing your door . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Carton inventory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Hardware inventory. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Assembly 5
Attach the drive sprocket . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Attach mounting brackets. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Installation 6-12
Installation safety instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Install the door sprocket. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Mount the operator. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Attach the emergency release rope and handle . . . . . . . . . . . . . . 8
Install the single button control station . . . . . . . . . . . . . . . . . . . . 8
Electrical requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Install The Protector System®. . . . . . . . . . . . . . . . . . . . . . . . 10-12
Adjustment 13-15
Program the travel limits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Set the force . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Test The Protector System®. . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
To open door manually. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Operation 16-18
Operation safety instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Using your operator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Care of your operator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Having a problem? (Troubleshooting) . . . . . . . . . . . . . . . . . . . . 17
Diagnostic chart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Programming 19-20
To add or reprogram a hand-held
remote control (not provided) . . . . . . . . . . . . . . . . . . . . . . . . . . 19
To erase all codes from motor unit memory . . . . . . . . . . . . . . . 19
To add, program or change a keyless entry
PIN (not provided) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Repair Parts 21
Installation parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Motor unit assembly parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Accessories 22
Notes 23
Repair Parts and Service Back Page
TABLE OF CONTENTS

3
Preparing Your Door
Before you begin:
• Remove any ropes connected to door.
• Raise and lower the door to ensure the door does not bind or
stick and is properly balanced. If your door binds, sticks or is
out of balance refer to the door manufacturer for more
information.
For live shaft type doors the drive shaft needs to extend 1-1/2"
beyond the door mount bracket.
• If the operator is mounted below 8 feet (2.5 m), a chain guard
must be installed to protect against possible injury. See
accessories page.
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.
• DO NOT run operator if the door is locked.
• Chain guard to be installed where the drive chain is exposed
lower than 8 feet (2.5 m).
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.
• DO NOT install operator below 6 feet (1.83 m).
Specifications
Volts . . . . . . . . . . . . . . . . . . . . . . . . .120 Vac - 60 Hz, ONLY
Current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.0 AMP
Rated Load . . . . . . . . . . . . . . . . . . . . . . . . . . . 325 in. lb/sec.
10 Cycles per Hour
Maximum Door Height . . . . . . . . . . . . . . . . . . . . . . . 12 feet
Maximum Door Size . . . . . . . . . . . . . . . . . . 14 feet x 12 feet
(not to exceed 168 sq./ft)

4
2-Conductor Bell Wire
White & White/Red
Safety Labels
and
Literature
Mounting Bracket (4)
Door Sprockets
The Protector System®
(2) Safety Reversing Sensors
(1 Sending Eye and 1 Receiving Eye)
with 2-Conductor White & White/Black
Bell Wire attached
Safety Reversing Sensor
Bracket (2)
Operator
Single Button Control
Station
12 Tooth Drive Sprocket
with Drive Chain
Carton Inventory
Your door operator is packaged in one carton which contains the
motor unit and the parts illustrated below.
Note that accessories will depend on the model purchased. If
anything is missing, carefully check the packing material.
Hardware Inventory
Installation Hardware
Tubular Spacer 1/2" (6)
Tubular Spacer 2" (3)
Cap Screw 1/4"-20 x 2" (1)
Nylock Lock Nut 1/4"-20 (1)
Hex Head Bolt 3/8"-16 x 4" (3)
Flat Washer 3/8" (3)
Serrated Flange Nut 5/16"-18 (3)
Carriage Head Bolt 1/4"-20 x 1/2" (2)
Self Taping Screw #10-32 (8)
Rope (1)
Handle (1)
Wing Nut 1/4"-20 (2)
Hex Drive Round Head Bolt 1/4"-20 x 1/2" (2)
Warning Tag for Release Handle (1)

5
Operator
Mounting Brackets
ASSEMBLY STEP 1
Attach the Drive Sprocket
The drive sprocket can be installed on the right or left side of the
operator depending on your installation. The drive sprocket has
three holes to aid in the alignment of the drive sprocket with the
door sprocket.
1. Insert the drive sprocket into the output shaft.
2. Align the center holes in the drive sprocket with the hole in the
output shaft.
3. Insert bolts into the output shaft and the drive sprocket.
4. Finger tighten the bolts.
ASSEMBLY STEP 2
Attach Mounting Brackets
The operator can be mounted to the wall with the mounting
brackets provided. An optional guide mounting bracket is
available for purchase (see accessories).
1. Position two mounting brackets on each side of the operator.
2. Fasten the mounting brackets to the operator using the
self-threading screws (8) provided.
Figure 1
Figure 2
Output Shaft
Drive Sprocket
Bolt
Bolt

6
INSTALLATION
IMPORTANT INSTALLATION INSTRUCTIONS
To reduce the risk of SEVERE INJURY or DEATH:
WARNING
WARNING
WARNINGWARNING
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 Mount emergency release handle no higher than 6 feet
(1.83 m) above floor.
6. NEVER connect door operator to power source until
instructed to do so.
7. NEVER wear watches, rings or loose clothing while installing
or servicing operator. They could be caught in door or
operator mechanisms.
8. Install wall-mounted door control:
• within sight of the door.
• out of reach of children at minimum height of 5 feet
(1.5 m).
• away from ALL moving parts of the door.
9. Install the Entrapment Warning Placard next to the control
station in a prominent location.
10. Place manual release/safety reverse test label in plain view
on inside of door.
11. Upon completion of installation, test safety reversal system.
12. Install the operator at least 8 feet (2.5 m) or more above the
floor if the operator has exposed moving parts.
INSTALLATION STEP 1
Install the Door Sprocket
The instructions below are general and we recommend you refer
to the door manufacturer for specific instructions for your door.
Live shaft type (Figure 1):
1. Slide the door sprocket onto the end of the door shaft.
2. Mark and drill a hole through the door shaft.
3. Attach the door sprocket to the door shaft with the through
bolt and nylock nut.
NOTE: Drive shaft must extend 1-1/2" beyond the door support
bracket.
Dead shaft type (Figure 2):
1. Slide the door sprocket onto the end of the door shaft.
2. Slide the through bolts with flat washers into the door sprocket
with tubular spacers and attach to the door drum.
3. Secure the sprocket to the drum as shown.
Door
Door
Door Shaft
Drum
Door Sprocket
Through Bolt
Nylock
Nut
Door
Sprocket
Figure 1
Figure 2
Flange Nut
Drum
Door
Sprocket
Door Bracket
Drum
Tubular
Spacer
Flat Washer
Door
Sprocket

7
INSTALLATION STEP 2
Mount the Operator
The operator can be mounted to the wall with the mounting
brackets provided.
An optional guide mounting bracket is available for purchase
(see accessories).
Fasten the operator to the mounting surface using appropriate
method and hardware (not provided).
Anchors must be fastened to structural members only. Use
concrete anchors for masonry construction.
NOTE: Mounting the operator to drywall is not recommended.
1. Raise the operator to approximate mounting position, make
sure the drive sprocket is aligned with the door sprocket.
NOTE: If the drive and the door sprockets are not aligned, the
drive sprocket can be laterally adjusted by removing the bolt
from the drive sprocket.
2. Wrap the chain around the door and drive sprockets.
3. Connect the ends of the chain using the master link (provided).
4. Raise or lower the operator until the chain is taut (not tight).
Make sure the operator output shaft is parallel to door shaft
and sprockets are aligned.
5. Secure the operator to wall using appropriate method.
6. Tighten the drive sprocket bolts using a 5/32" Allen wrench.
Live Shaft
Dead Shaft
Operator
Chain
Mounting
Hardware
(not provided)
Chain
Operator
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 door
shaft.
Mounting
Hardware
(not provided)

8
WHT/RED
WHT
Door Control
Connections
Single Button Control Station
INSTALLATION STEP 4
Install the Single Button Control Station
1. Remove the control station cover.
2. Fasten the control station to the wall at least 5 feet (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.
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.
Factory installed
jumper must be in
place for proper
operation. Operator
will not function
without the jumper.
NOTICE
Overhand
Knot
Emergency
Release Handle
Overhand
Knot
Rope
Motor Unit
Emergency
Release Cable
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.
INSTALLATION STEP 3
Attach the Emergency Release Rope and Handle
1. Thread one end of the rope through the hole in the top of the
red handle so “NOTICE” reads right side up as shown. Secure
with an overhand knot at least 1" (2.5 cm) from the end of the
rope to prevent slipping.
2. Thread the other end of the rope through the loop in the
emergency release cable.
3. Adjust rope length so the handle is no higher than 6 feet
(1.83 m) above the floor. 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.
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.
WARNING
Keep Door in Sight at all Times When Door is Moving
Moving Door Can Cause
Serious Injury or Death
Keep Clear! Door May Move at any Time
Without Prior Warning
Do Not Let Children Operate the Door or Play
in the Door Area

9
INSTALLATION STEP 5
Electrical Requirements
To avoid installation difficulties, do not run the operator at this
time.
To reduce the risk of electric shock, your 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.
RIGHT WRONG
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 operator (according to local code):
1. Remove cover screws and set the cover aside.
2. Remove the attached green ground terminal.
3. Cut black and white wires and strip away 1/2" (1.3 cm) of
insulation, 3" (7.6 cm) before spade terminals.
4. Remove the power cord from unit.
5. Install a 90º conduit or flex cable adapter to the 7/8" hole.
6. Run wires through conduit, cut to proper length and strip
insulation.
7. Attach with wire nuts.
8. Properly secure wire under plastic ties so that wire does not
come in contact with moving parts.
9. Reinstall the cover.
To avoid installation difficulties, do not run the operator at this
time.
Black Wire
From Power Cord
White Wire
From Power Cord
Ground Tab
Green
Ground
Screw
Ground Wire
Flexible Conduit
PERMANENT WIRING CONNECTION
90˚ Connector
Green Wire White Wire
Black Wire
PERMANENT WIRING CONNECTION
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.

10
Invisible Light Beam
Protection Area
Safety Reversing Sensor
6" (15 cm) max. above floor
Safety Reversing Sensor
6" (15 cm) max. above floor
Facing the door from inside.
INSTALLATION STEP 6
Install The Protector System®
The safety reversing sensor must be connected and aligned
correctly before the door operator will move in the down
direction. This is a required safety device and cannot be
disabled.
IMPORTANT INFORMATION ABOUT THE SAFETY REVERSING
SENSOR
When properly connected and aligned, the safety reversing sensor
will detect an obstacle in the path of its electronic beam. The
sending eye (with an amber indicator light) transmits an invisible
light beam to the receiving eye (with a green indicator light). If an
obstruction breaks the light beam while the door is closing, the
door will stop and reverse to full open position.
The units must be installed inside the building so that the sending
and receiving eyes 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 eye lens.
If it is necessary to mount the units 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.
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.