Set The Tension; Installation - Craftsman 139.53914 Owner's Manual

ASSEMBLY STEP 5
Set the Tension
• Insert a screwdriver tip into one of the nut ring
slots and brace it firmly 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.
You have now finished assembling your garage
door opener. Please read the following warnings
before proceeding to the installation section.
J
Nut Ring Slot
Trolley
Square
End Nut Ring
(2.5 cm) (3.18 cm)
Nut Ring,
INSTALLATION
IMPORTANT INSTALLATION INSTRUCTIONS
To reduce the risk of severe injury or death:
1. READAND FOLLOWALL 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
SEVEREINJURY 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 releasehandle 6 feet (1.83 m) above
floor.
7. NEVERconnect garage door opener to power source
until instructed to do so.
8. NEVERwear 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
(1.5m).
• away from all moving parts of the door.
10. Placeentrapment 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.
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