Chamberlain HD920EV Owner's Manual page 12

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 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.
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 :
2" (5 cm) above the high point for sectional door and one-piece door with track.
l
8" (20 cm) above the high point for one-piece door without track.
l
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 12 for
ceiling installation.
Header Wall
Vertical Centerline of Garage Door
Level
(Optional)
Header Wall
2" (5 cm)
Track
Highest Point
of Travel
Door
Sectional door with curved track
Header Wall
8" (20 cm)
Door
Highest
Point of
Travel
Jamb
Hardware
One-piece door without track:
jamb hardware
11
OPTIONAL CEILING MOUNT
FOR HEADER BRACKET
2x4
Structural
Supports
Unfinished
Ceiling
Header Wall
2" (5 cm)
Door
Highest
Point
of Travel
One-piece door with horizontal track
Header Wall
Door
One-piece door without track:
pivot hardware
2x4
Track
8" (20 cm)
Highest
Point of
Travel
Pivot