Set The Belt Tension; Installation; Installation Safety Instructions - Craftsman 139.53964SRT 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.
End
Trolley
Nut Ring
(2.5 cm)
Nut Ring Slot
! End
Nut Ring /
(3.18 cm)
INSTALLATION
IMPORTANT INSTALLATION INSTRUCTIONS
To reduce the risk of severe injury or death:
1. READAND FOLLOWALL INSTALLATION WARNINGS 8. NEVERwear watches, rings or loose clothing while
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
SEVEREINJURYor 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 powersource
until instructed to do so.
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
(1.52m)
• away from all moving parts of the door.
10. Placeentrapment warning label on wall next to garage
door control.
11. Placemanual release/safetyreverse 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 one-
inch (2.5 cm) high object (or a 2 x 4 laid flat) on the
floor.
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