Chamberlain 3885C - Manuel (Page 8)

8
INSTALLATION STEP 1
Determine the Header Bracket
Location
Installation procedures vary according to garage door
types. Follow the instructions which apply to your
door.
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
(1.22 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 9) 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 9.
3. Open your door to the highest point of travel as
shown. Draw an intersecting horizontal line on the
header wall above the high point:
• 2" (5 cm) above the high point for sectional door
and one-piece door with track.
• 8" (20 cm) above the high point for one-piece
door without track.
This height will provide travel clearance for the top
edge of the door.
NOTE: If the total number of inches exceeds the
height available in your garage, use the maximum
height possible, or refer to page 9 for ceiling
installation.
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.
One-piece door with horizontal track
Door
Track Header Wall
Highest Point
of Travel
2" (5 cm)
Header Wall
Vertical Centerline
of Garage Door
Level
(optional)
2x4
2x4
Structural
Supports
OPTIONAL
CEILING
MOUNT
FOR
HEADER
BRACKET
Unfinished
Ceiling
WARNING
CAUTION WARNING
WARNING
Door
Jamb
Hardware
One-piece door without track:
jamb hardware
8" (20 cm)
Highest
Point
of Travel
Door
Pivot
8" (20 cm)
One-piece door without track:
pivot hardware
Highest
Point
of Travel
Header Wall
Header Wall
Header Wall
Sectional door with curved track
Highest Point
of Travel
Door
2" (5 cm) Track