Chamberlain 1246R - 1/3HP Garage Door Opener User Manual


 
12
INSTALLATION STEP 1
Determine the Header Bracket
Location
Installation procedures vary according to garage door
types. Follow the instructions which apply to your
door.
SECTIONAL DOOR
AND ONE-PIECE DOOR WITH TRACK
1. Close the door and mark the inside vertical
centerline of the garage door.
2. Extend the line onto the header wall above the
door.
You can fasten the header bracket within 4 feet
(1.2 m) of the left or right of the door center
only if a torsion spring or center bearing plate
is in the way; or you can attach it to the ceiling
(see page 10) when clearance is minimal. (It
may be mounted on the wall upside down if
necessary, to gain approximately 1/2" (1 cm).)
If you need to install the header bracket on a 2x4
(on wall or ceiling), use lag screws (not provided)
to securely fasten the 2x4 to structural supports as
shown here and on page 13.
3. Open your door to the highest point of travel as
shown. Draw an intersecting horizontal line on the
header wall 2" (5 cm) above the high point. This
height will provide travel clearance for the top edge
of the door.
Proceed to Step 2, page 14.
One-piece
door with
horizontal
track
To prevent possible SERIOUS INJURY or DEATH:
• Header bracket MUST be RIGIDLY fastened to
structural support on header wall or ceiling, otherwise
garage door might not reverse when required. DO NOT
install header bracket over drywall.
• Concrete anchors MUST be used if mounting header
bracket or 2x4 into masonry.
• NEVER try to loosen, move or adjust garage door,
springs, cables, pulleys, brackets, or their hardware, all
of which are under EXTREME tension.
• ALWAYS call a trained door systems technician if
garage door binds, sticks, or is out of balance. An
unbalanced garage door might not reverse when
required.
Header Wall
Ceiling
Track
Highest Point
of Travel
Door
2" (5 cm)
Sectional door
with curved
track
Door
Track
Header Wall
Highest Point
of Travel
2" (5 cm)
Finished
Ceiling
Header
Wall
2x4
Structural
Supports
Vertical
Centerline
of Garage Door
WARNING
CAUTION
WARNING
WARNING