Chamberlain WHISPER DRIVE 248754 - Manual (Page 4)

4
Planning
Identify the type and height of your garage door. Survey
your garage area to see if any of the conditions below
apply to your installation. Additional materials may be
required. You may fi nd it helpful to refer back to this page
and the accompanying illustrations as you proceed with
the installation of your opener.
Depending on your requirements, there are several
installation steps which may call for materials or hardware
not included in the carton.
• Installation Step 1 – Look at the wall or ceiling above
the garage door. The header bracket must be securely
fastened to structural supports.
• Installation Step 5 – Do you have a fi nished ceiling in
your garage? If so, a support bracket and additional
fastening hardware may be required.
• Installation Step 11 – Depending upon garage
construction, extension brackets or wood blocks may
be needed to install sensors.
• Installation Step 11 – Alternate fl oor mounting of
the safety reversing sensor will require hardware not
provided.
• Do you have an access door in addition to the garage
door? If not, Model 7702CB Emergency Key Release is
required. See Accessories page.
• Look at the garage door where it meets the fl oor. Any
gap between the fl oor and the bottom of the door must
not exceed 1/4" (6 mm). Otherwise, the safety reversal
system may not work properly. See Adjustment Step 3.
Floor or door should be repaired.
SECTIONAL DOOR INSTALLATIONS
• Do you have a steel, aluminum, fi berglass or glass
panel door? If so, horizontal and vertical reinforce ment
is required (Installation Step 12).
• The opener should be installed above the center of the
door. If there is a torsion spring or center bearing plate
in the way of the header bracket, it may be installed
within 4 feet (1.2 m) to the left or right of the door
center. See Installation Steps 1 and 12.
• If your door is more than 7 feet (2.1 m) high, see rail
extension kits listed on Accessories page.
— — — — — — — —
SECTIONAL DOOR INSTALLATION
Header Wall
FINISHED CEILING
Horizontal and vertical reinforcement
is needed for lightweight garage
doors (fi berglass, steel, aluminum,
door with glass panels, etc.).
See page 25 for details.
Support bracket &
fastening hardware
is required.
See page 16.
Motor unit Extension
Spring
Vertical
Centerline
of Garage Door
Wall-
mounted
Door
Control
Straight
Door
Arm
Emergency
Release Rope
& Handle
Header
Wall
Belt
Trolley
Stop Bolt
Trolley
CLOSED POSITION
Garage
Door
Spring
Garage
Door
Door
Bracket Curved
Door Arm
Header
Bracket
Gap between fl oor
and bottom of door
must not exceed 1/4" (6 mm).
Torsion
Spring
OR
Access
Door
Safety
Reversing
Sensor
Safety Reversing
Sensor