Chamberlain GARAGE DOOR OPENER CG40D 1/2 HP Owner's Manual page 5

Planning (Continued)
ONE-PIECE DOOR INSTALLATIONS
• Generally, a one-piece door does not require
reinforcement. If your door is lightweight, refer to the
information relating to sectional doors in Installation
Step 11.
• Depending on your door's construction, you may need
additional mounting hardware for the door bracket
(Step 11).
ONE-PIECE DOOR WITHOUT TRACK
Header Wall
Gap between floor
and bottom of door must not exceed 1/4" (6 mm).
Safety Reversing Sensor
ONE-PIECE DOOR WITH TRACK
Safety
Reversing Sensor
Rail
Slack in chain tension
is normal when garage
door is closed.
Wall-mounted
Door Control
Access
Door
Safety Reversing
Sensor
Access
Door
Safety
Reversing
Gap between floor
Sensor
and bottom of door
must not exceed 1/4" (6 mm).
Without a properly working safety reversal system, persons
(particularly small children) could be SERIOUSLY INJURED or
KILLED by a closing garage door.
• The gap between the bottom of the garage door and the floor
MUST NOT exceed 1/4" (6 mm). Otherwise, the safety
reversal system may not work properly.
• The floor or the garage door MUST be repaired to eliminate
the gap.
Motor Unit
Trolley Stop Bolt
Header
Bracket
Door Bracket
Header
Wall
CLOSED POSITION
Trolley Stop Bolt
Header
Wall
Curved
Header
Door Arm
Bracket
Door
Bracket
Garage
Door
5
CLOSED POSITION
Trolley
Cable
Rail
Straight
Curved
Door
Door
Arm
Arm
Garage Door
Chain
Cable
Rail
Emergency
Release
Straight
Rope &
Door
Handle
Arm
Emergency
Release
Rope & Handle