Chamberlain 547445 User Manual

5

•   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 12.

•   Depending on your door’s construction, you may need 

additional mounting hardware for the door bracket 
(Step 12).

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 fl oor MUST NOT exceed 1/4" (6 mm). Otherwise, 
the safety reversal system may NOT work properly.

•  The fl oor or the garage door MUST be repaired to 

eliminate the gap.

Straight
Door Arm

Emergency 
Release 
Rope & 
Handle

Header
Wall

Header Wall

Belt

Rail

Rail

Trolley Stop Bolt

Trolley 

Garage
Door

Door Bracket

Curved
Door
Arm

Header
Bracket

Straight
Door 
Arm

Emergency 
Release 
Rope & 
Handle

Header
Wall

Belt

Rail

Trolley Stop Bolt

Trolley 

Garage
Door

Door 
Bracket

Curved
Door Arm

Header
Bracket

Gap between fl oor 
and bottom of door
must not exceed 1/4" (6 mm).

Gap between fl oor and 
bottom of door must 
not exceed 1/4" (6 mm).

Safety
Reversing
Sensor

Safety Reversing Sensor

Safety 
Reversing
Sensor

Safety Reversing 
Sensor

Access 
Door

Access 
Door

FINISHED CEILING

Support bracket & 
fastening hardware
is required.
See page 16.

Motor unit

Wall-mounted
Door Control