Chamberlain WHISPER DRIVE HD900D - Manual (Page 4)

4
Safety Reversing Sensor
Header Wall
Access Door
— — — — — — — —
Safety
Reversing
Sensor
Gap between floor
and bottom of door
must not exceed 1/4" (6 mm).
Extension Spring
Horizontal and vertical reinforcement
is needed for lightweight garage doors
(fiberglass, steel, aluminum, door with
glass panels, etc.). See page 24 for details.
Support bracket &
fastening hardware
is required.
See page 16.
FINISHED CEILING
Motor unit
Wall-
mounted
Door
Control
OR
Torsion Spring
Vertical
Centerline
of Garage Door
SECTIONAL DOOR INSTALLATION
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 find 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 finished 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 floor mounting of the safety
reversing sensor will require hardware not provided.
CLOSED POSITION
Header
Wall
Garage
Door
Header
Bracket
Trolley
Straight
Door
Arm
Emergency Release
Rope & Handle
Door
Bracket
Curved
Door
Arm
Garage
Door
Spring
Belt
Trolley
Stop Bolt
• 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 floor. Any gap
between the floor 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, fiberglass 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.