LiftMaster SECURITY+ 3245CM 1/3 HP Manuel Du Propriétaire page 8

INSTALLATION STEP 1
Determine the Header Bracket Location
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.
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 inter secting 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.
Unfi nished Ceiling
Header Wall
Header Wall
2" (5 cm)
Highest
Point of
Travel
Door
Sectional door with
curved track
Header
Wall
8" (20 cm)
Door
Jamb
Hardware
Highest
Point of
Travel
One-piece door without track:
jamb hardware
8
2x4
Vertical Centerline
of Garage Door
2x4
Level
(optional)
Header Wall
Track
Door
One-piece door with
horizontal track
Header Wall
8" (20 cm)
Door
One-piece door without track:
pivot hardware
OPTIONAL
CEILING
MOUNT FOR
HEADER
BRACKET
Structural
Supports
2" (5 cm)
Track
Highest
Point of
Travel
Highest
Point of
Travel
Pivot