Chamberlain 459950 Manual De Usuario

11

•   Insert a screwdriver tip into one of the nut ring slots 

and brace it fi rmly against the trolley.

•   Place a 7/16" open end wrench on the square end. 

Rotate the nut about 1/4 turn until the spring releases 
and snaps the nut ring against the trolley.

This sets the spring to optimum belt tension.

1.   READ AND FOLLOW ALL INSTALLATION 

WARNINGS AND INSTRUCTIONS.

2.   Install garage door opener ONLY on properly 

balanced and lubricated garage door. An improperly 
balanced door may NOT reverse when required and 
could result in SEVERE INJURY or DEATH. 

3.   ALL repairs to cables, spring assemblies and other 

hardware MUST be made by a trained door systems 
technician BEFORE installing opener.

4.   Disable ALL locks and remove ALL ropes connected 

to garage door BEFORE installing opener to avoid 
entanglement.

5.   Install garage door opener 7 feet (2.1 m) or more

above fl oor.

6.   Mount the emergency release within reach, but at 

least 6 feet (1.8 m) above the fl oor and avoiding 
contact with vehicles to avoid accidental release.

7.   NEVER connect garage door opener to power source 

until instructed to do so. 

  8.   NEVER wear watches, rings or loose clothing 

while installing or servicing opener. They could be 
caught in garage door or opener mechanisms.

  9.  Install wall-mounted garage door control:  
 

• within sight of the garage door. 

 

•  out of reach of children at minimum height

of 5 feet (1.5 m).

 

• away from ALL moving parts of the door.

10.   Place entrapment warning label on wall next to 

garage door control.

11.   Place manual release/safety reverse test label in 

plain view on inside of garage door.

12.   Upon completion of installation, test safety reversal 

system. Door MUST reverse on contact with a 
1-1/2" (3.8 cm) high object (or a 2x4 laid fl at) on 
the fl oor.

13.   To avoid SERIOUS PERSONAL INJURY or DEATH 

from electrocution, disconnect ALL electric and 
battery power BEFORE performing ANY service or 
maintenance.

Nut Ring

Nut Ring

Trolley

Square 
End

Square 
End

BEFORE

1"

(2.5 cm)

AFTER RELEASE

1-1/4"

(3.18 cm)

Nut 
Ring 
Slot