Craftsman 1/2 HP GARAGE DOOR OPENER 139.53978SRT - Manual (Page 21)

The Safety Reversing System
IMPORTANT INFORMATION ABOUT THE
SAFETY REVERSING SENSOR
The safety reversing sensor must\i& connected
and aligned correctly before the garage door
opener will move in the down direction. This is a
required safety device and cannot be disabled.
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
orange 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, and the opener light will flash
10 times.
The units must be installed inside the garage so
that the sending and receiving eyes face each other
across the door, between 4 - 6" 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.
The mounting brackets are designed to clip onto the
track of sectional garage doors without additional
hardware.
Without a proparly working safety reversing
sensor, persons (particuiariy chiidren) could
be injur^ or killed by a dosing garage door.
Read and follow all instructions.
To protect small children, install the safety
reversing sensor so that the beam will be
between 4 - 6" above the garage floor.
Disconnect power to the garage door opener
before installing the safety reversing sensor.
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 garage door (or door tracks, springs,
hinges, rollers or other hardware) may interrupt the
beam while the door is closing.
Figure 1 : Facing the door from inside the garage
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