Chamberlain 1240R - 1/4HP Garage Door Opener User Manual


 
11
ASSEMBLY STEP 5
Tighten the Chain
ALL MODELS
Spin the inner nut and lock washer down the
trolley threaded shaft, away from the trolley.
To tighten the chain, turn outer nut in the direction
shown. AS YOU TURN THE NUT, KEEP THE
CHAIN FROM TWISTING.
When the chain is approximately 1/2" (13 mm)
above the base of the rail at its midpoint, re-tighten
the inner nut to secure the adjustment.
Sprocket noise can result if chain is either too
loose or too tight.
NOTE: When installation is complete, you may
notice some chain droop with the door closed. This is
normal. If the chain returns to the position shown
when the door is open, do not re-adjust the chain.
NOTE: During future maintenance, ALWAYS pull the
emergency release handle to disconnect trolley
before adjusting chain.
You have now finished assembling your garage
door opener. Please read the following warnings
before proceeding to the installation section.
Lock
Washer
To Tighten Outer Nut
Inner Nut
Trolley
Chain
Base of Rail
1/2" (13 mm)
To Tighten
Inner Nut
Outer Nut
Mid Length of Rail
IMPORTANT INSTALLATION INSTRUCTIONS
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 (2.13 m) or more
above floor.
6. Mount emergency release handle 6 feet (1.83 m) above
floor.
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 flat) on
the floor.
To reduce the risk of SEVERE INJURY or DEATH:
WARNING
WARNING
WARNING
INSTALLATION