Planning - Chamberlain LiftMaster 3275C Owner's Manual

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.
SECTIONAL DOOR INSTALLATION
Horizontal and vertical reinforcement
is needed for lightweight garage doors
(fiberglass, steel, aluminum, door with
glass panels, etc.). See page 19 for details.
Header Wall
Safety Reversing Sensor
ONE-PIECE DOOR WITHOUT TRACK
Header
Wall
Gap between floor and bottom of
door must not exceed 1/4" (6 mm)
Safety
Reversing Sensor
Torsion
Spring
Vertical
Centerline
of Garage Door
Safety
Reversing
Gap between floor
Sensor
and bottom of door
must not exceed 1/4" (6 mm)
Wall-
mounted
Door
Control
Safety
Reversing Sensor
You may find it helpful to refer back to this page and the
accompanying illustrations as you proceed with the installation of
your opener.
FINISHED CEILING
Support bracket &
fastening hardware
is required.
See page 12.
Slack in chain tension
is normal when
garage door is closed.
Extension Spring
OR
OR
One-Piece Door-Extension Spring
Header Wall
Track
Door
ONE-PIECE DOOR WITH TRACK
Access
Door
4
Motor Unit
Access
Door
Wall-
mounted
Door
Control
Motor Unit
Gap between floor
and bottom of door
Safety
must not exceed 1/4" (6 mm)
Reversing Sensor
Access
Door
Safety
Reversing Sensor