13
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. The LiftMaster Light Curtain LC36A may be installed as an optional
secondary safety device, see page 16.
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 full open position.
The sensors 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 sensor 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.
Install The Protector System
5
Installation
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.
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 the building.
NOTE:
If the LC36M/LC36M41 Monitored Light Curtain is used in place of Protector
System Safety Reversing Sensors, please use the Installation Instructions that are
provided with the LC36M/LC36M41.
