Safety Information Regarding Garage Door Locks And Ropes; Testing Your Garage Door For Sticking, Binding And Balance - Chamberlain Lift-Master Professional 1270 Owner's Manual

Before you begin, survey your garage area to see whether any of the conditions below apply to your installation.
SECTIONAL Door or ONE-PIECE Door
with Track Installation
FINISHED CEILING
Support bracket &
fastening hardware
is required.
Horizontal and vertical reinforcement
See page 13.
is needed for lightweight garage doors
Slack in belt tension
(fiberglass, steel, aluminum, door with glass panels, etc.).
is normal when
See page 20 for details.
garage door is closed.
Header Wall
Extension Spring
OR
OR
One-Piece Door-Extension Spring
Torsion Spring
Header
Wall
Door Center
Access Door
Track
Door
Safety
Reversing
Sensor
Floor must be level
across width of door
Safety Reversing Sensor
ONE-PIECE Door Without Track Installation
Header
Wall
Access Door
Safety
Reversing
Sensor
Gap between floor and bottom of
door must not exceed 1/4".
Safety Reversing Sensor
You may find it helpful to refer back to this page as you proceed with the installation of your opener.
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