Chamberlain 3240 1/2 HP ユーザーズマニュアル

4

Safety Reversing Sensor

FINISHED CEILING

Support bracket
& fastening
hardware is required.
See page 19.

Safety Reversing 
Sensor

Access
Door

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

Wall-mounted
Door Control

Header Wall

Motor
Unit

Rail

Safety Reversing Sensor 

Horizontal and vertical reinforcement 
is needed for lightweight garage doors 
(fiberglass, steel, aluminum, door with 
glass panels, etc.). See page 19 for details. 

Support bracket &  
fastening hardware 
is required. 
See page 15. 

 — — —        — — —        — — 

Header Wall 

Safety Reversing 
Sensor 

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

FINISHED CEILING 

Torsion 
 Spring 
 
 

Access Door 

Motor Unit

Wall- 
mounted 
Door  
Control 

Rail 

Extension 
 Spring 
 

OR  

Vertical 
Centerline 
of Garage 
Door 

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.

Safety 
Reversing Sensor

Safety 
Reversing Sensor

Access
Door

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

Header
Wall

15.