Chamberlain PD220 Manual De Instrucciones página 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,
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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.
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NEVER try to loosen, move or adjust garage door, springs, cables, pulleys, brackets, or their
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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.
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An unbalanced garage door might NOT reverse when required.
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.
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
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OPTIONAL CEILING MOUNT
FOR HEADER BRACKET
2x4
Structural
Supports
Unfinished
Ceiling
2x4