Craftsman 1/2 HP GARAGE DOOR OPENER 139.53978SRT - Manual (Page 22)

Figure 2
door track mount (Right side)
INSTALLING THE BRACKETS
Be sure power to the opener is disconnected.
Install and align the brackets so the sensors will
face each other across the garage door, with the
beam from 4 - 6“ above the floor.
They may be installed in one of three ways, as
follows.
Garage door track installation (preferred):
• Slip the curved arms over the rounded edge of
each door track, with the curved arms facing the
door. Snap into place against the side of the track.
It should lie flush, with the lip hugging the back
edge of the track, as shown in Figure 2.
If your door track will not support the bracket
securely, wall installation is recommended.
Wall installation:
• Place the bracket against the wall with curved
arms facing the door. Be sure there is enough
clearance for the sensor beam to be unobstructed.
• If additional depth is needed, an extension bracket
(see Accessories) or wood blocks can be used.
• Use bracket mounting holes as a template to
locate and drill (2) 3/16" diameter pilot holes on the
wall at each side of the door, from 4-6" above the
floor. (See warning at beginning of Installation
Step 10.)
• Attach brackets to wall with lag screws (not
provided).
• If using extension brackets or wood blocks, adjust
right and left assemblies to the same distance out
from the mounting surface. Make sure all door
hardware obstructions are cleared.
Floor installation:
• Use wood blocks or extension brackets (see
Accessories) to elevate sensor brackets so the
lenses will be 4-6" above the floor.
• Carefully measure and place right and left
assemblies at the same distance out from the wall.
Be sure all door hardware obstructions are
cleared.
• Fasten to the floor with concrete anchors as
shown.
Figure 3
wall mount (Right side)
Figure 4
floor mount (Right side)
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