Planning - Chamberlain LiftMaster Security+ 1245LMC-R-1/3HP 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. You may find 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
(fiberglass, steel, aluminum, door with
glass panels, etc.). See page 19 for details.
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
Header Wall
Torsion
Spring
Vertical
Centerline of
Garage Door
Safety
Gap between floor Reversing
and bottom of door Sensor
must not exceed 1/4" (6 mm)
Wall-mounted
Door Control
Access
Door
Safety Reversing
Sensor
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
Wall-
mounted
Access
Door Door
Control
Motor Unit
ONE-PIECE DOOR WITH TRACK
Safety
Reversing Sensor
4
Motor unit
Access
Door
Safety Reversing
Gap between floor
Sensor
and bottom of door
must not exceed 1/4" (6 mm).