
Installation procedures are the
same for sectional and onepiece doors.
Without a properly working safety reversing
sensor, persons (particularly children) could
be killed by a closing garage door. Read and
follow all instructions.
To protect small children, install the Protector
System so that the beam will be no higher
than 4"-6" above the garage floor.
Disconnect power to the garage door opener
before installing the Protector System.
The Protector System
™
Safety Reversing Sensor Model Series 870CB
1
The brackets must be securely fastened to a solid
surface such as the studs on either side of the door,
or add a piece of wood at each location if installing in
masonry construction.
The invisible light beam path must be unobstructed.
No part of the garage door (or door tracks, springs,
hinges, rollers or other hardware) can interrupt the
beam while the door is closing. If it does, use a piece
of wood to build out each sensor mounting location to
the minimum depth required for light beam clearance.
Be sure power to the opener is disconnected.
The sending eye transmits an invisible light beam to
the receiving eye.The units can be installed on either
side of the garage door as long as the sun never
shines directly into the receiving eye lens.
Look at the label on the connector end of each case
to identify the sensors.
The brackets must be connected and fastened so that
the sending and receiving eyes face each other as
shown in Figure 1.
If an obstruction breaks the light beam while the
garage door is closing, the door will stop and reverse
to full open position; and the opener lights will flash
for 5 seconds.
FIGURE 1 Facing the door from inside the garage
WARNING
Sensor Beam
4-6" max.
above floor
Sensor Beam
4-6" max.
above floor
Invisible Light Beam
Protection Area

Figures 2 and 3 show assembly of brackets and "C"
wrap based on the recommended installation of the
sensors as shown on page 1. Figures 4 and 5 are
variations which may fit your installation requirements
better. Make sure the wraps and brackets are
aligned so the sensors will face each other across
the garage door.
• Fasten the "C" wraps to the mounting brackets
having square holes, using the hardware shown in
Figure 2.
• Connect each assembly to a slotted bracket, using
the hardware shown in Figure 3.
Note the alignment of the brackets for left and
right sides of the door.
• Finger tighten the lock nuts.
• Use bracket mounting holes as a template to locate
and drill (2) 3/16" diameter pilot holes on both sides
of the garage door, 4"-6" above the floor but not
exceeding 6".
• Attach bracket assemblies with 1/4"x1-1/2" lag
screws as shown in Figure 3.
• Adjust right and left side bracket assemblies to the
same distance out from the mounting surface. Make
sure all door hardware obstructions are cleared.
Tighten the nuts securely.
Mounting Bracket
With Square Holes
#10-32x3/8"
Screws
"C" Wrap
#10-32
Lock Nuts
Mounting Bracket
with Slot
1/4"-20
Lock Nuts
1/4x1-1/2"
Lag Screws
1/4-20x1/2" Carriage Bolts
(with square shoulder)
Inside
Garage
Wall
"C" Wrap
Mounting Bracket
with Square Holes
1/4 x 1-1/2"
Lag Screw
#10 - 32 x 3/8"
Screw
1/4" - 20
Lock Nut
#10 x 32
Lock Nut
Staples
1/4" - 20 x 1/2"
Carriage Bolts
Hardware Shown Actual Size
"C" Wrap
Inside
Garage
Wall
Mounting Bracket
with Square Holes
Garage
Floor
Mounting Bracket
with Slot
Alternate Wall Mount
Sensor
with wire
Indicator Light
Indicator Light
Inside
Garage
Wall
Alternate Floor Mount
Mounting Bracket
with Slot
Attach with
concrete anchors
(not provided)
Mounting Bracket
with Square Holes
"C" Wrap
Sensor with wire
Garage
Floor

Invisible Light Beam
Protection Area
Sensor
Sensor
Connect Wire to
Opener Terminals
Bell Wire
Bell Wire
Finished
Ceiling
RED-1
WHT-2
BLK-3
OPENER TERMINAL SCREWS
Sensor
Connections
Door Control
Connections
(dotted line)
• Center each sensor unit in a "C" wrap with lenses
pointing toward each other across the door.
• Secure sensors with the hardware shown in
Figure 6. Finger tighten the wing nut on the receiving
eye to allow for final adjustment. Securely tighten
the sending eye wing nut.
• Run wires from both sensors to the opener as
shown. Use insulated staples to secure the wire to
the wall and ceiling.
• Connect both sets of wires to the opener terminals
as shown (depending upon your model).
• Plug in the opener. If your opener has the Multi-
Function Door Control, make sure the Lock Feature
is off. Indicator lights in both the sending and
receiving eyes will glow steadily if wiring connections
and alignment are correct.
If the indicator light is off in the receiving eye (and the
invisible light beam path is not obstructed), alignment
is required.
• Loosen the receiving eye wing nut to allow slight
rotation of unit. Adjust sensor vertically and/or
horizontally until the indicator light glows with a
steady light.
• When indicator lights are glowing steadily in both
units, tighten the wing nut in the receiving eye unit.
Hardware Shown Actual Size
FIGURE 6
3
Indicator
Light
1/4-20 x 1-1/2"
Hex Bolt
1/4-20 x 1-1/2"
"C" Wrap
Hex Bolt
Wing
Nut
Sensor
with Wire
Wing Nut

Test the Protector System™
• Press the remote control push button to open the
door.
• Place the opener carton in the path of the door.
• Press the remote control push button to close the
door. The door will not move more than an inch, and
the opener light(s) will flash.
The garage door opener will not close from a
remote control if the indicator light in either
sensor is off, (alerting you to the fact that the
sensor is misaligned or obstructed).
The garage door can be closed by pressing and
holding the Door Control push button until down travel
is completed.
Without a properly working Protector System
™
persons (particularly children) could be
seriously injured or killed by a closing garage
door. Repeat this test once a month.
Professional service is required if the opener
closes the door when the Protector System is
obstructed.
Test the Safety Reverse System
TEST:
• Place a one-inch board (or a 2x4 laid flat) on the
floor, centered under the garage door.
• Operate the door in the down direction. The door
must reverse on striking the obstruction.
ADJUSTMENT:
If the door stops on the obstruction, it is not traveling
far enough in the down direction.
• Increase the DOWN limit by turning the DOWN limit
adjustment screw counterclockwise 1/4 turn.
• Repeat the test.
On a sectional door, make sure limit adjustments
do not force the door arm beyond a straight up
and down position.
• When the door reverses on the one-inch object,
remove the obstruction and run the opener through
3 or 4 complete travel cycles to test adjustment.
If the door will not reverse after repeated
adjustment attempts, call for professional door
service.
Failure to test and adjust the safety reverse
system may result in serious injury or death
from a closing garage door. Repeat this test
once a month and adjust as needed.
One-Inch board (or a 2x4 laid flat)
Trouble Shooting
1. If the sending eye indicator light does not glow
steadily after installation, check for:
• Electric power to the opener.
• A short in the white or black/white wires. These
can occur under staples or at screw terminal
connections.
• Incorrect wiring between sensors and opener.
• An open wire (wire break).
2. If the sending eye indicator light glows steadily but
the receiving eye indicator light doesn’t:
• Check alignment.
• Check for an open wire to the receiving eye.
114A1577F ©1995, The Chamberlain Group, Inc. Printed in Mexico
All Rights Reserved
Replacement Parts
Safety sensor hardware bag . . . . . . . . . . . . . . . . .41A4116
Safety Sensor Kit (receiving and sending eyes
with 3' 2-conductor bell wire attached) . . . . . . . .41A4373A
C-Wrap Bracket . . . . . . . . . . . . . . . . . . . . . . . . . . .12B483
Square Hole Bracket . . . . . . . . . . . . . . . . . . . . . . . .12B484
Slotted Bracket . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12B485
WARNING
WARNING