Chamberlain LiftMaster Security+ 3265CM Manuel D'instructions page 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.
SECTIONAL DOOR INSTALLATION
Horizontal and vertical reinforcement
is needed for lightweight garage doors
(fi berglass, steel, aluminum, door with
glass panels, etc.). See page 19 for details.
Safety Reversing Sensor
ONE-PIECE DOOR WITHOUT TRACK
Header Wall
Gap between fl oor and bottom of door
must not exceed 1/4" (6 mm)
Safety Reversing
Sensor
Header Wall
Vertical Centerline
of Garage Door
Gap between fl oor and bottom of
door must not exceed 1/4" (6 mm).
Slack in chain tension
is normal when garage
door is closed.
Wall-
mounted
Door
Control
Access
Door
Safety Reversing Sensor
FINISHED CEILING
Support bracket &
fastening hardware is
required. See page 11.
Slack in chain tension
is normal when garage
door is closed.
Extension Spring
OR
Torsion Spring
Safety Reversing Sensor
FINISHED CEILING
Support bracket &
fastening hardware is
required. See page 11.
ONE-PIECE DOOR WITH TRACK
Safety Reversing
Sensor
4
Wall-mounted
Door Control
Access Door
Motor Unit
Slack in chain tension is normal
when garage door is closed.
Safety Reversing Sensor
Gap between fl oor and bottom of
door must not exceed 1/4" (6 mm)
Motor Unit
Access
Door