Craftsman 315 SERIES 139.53939D - Manual (Page 11)

11
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.
Nut Ring Nut Ring
Trolley
1" 1-1/4"
BEFORE AFTER RELEASE
Nut Ring Slot
Square End
Square
End
(2.5 cm) (3.18 cm)
INSTALLATION
IMPORTANT INSTALLATION INSTRUCTIONS
To reduce the risk of SEVERE INJURY or DEATH:
WARNING
WARNING WARNING
WARNING
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
floor.
6. Mount emergency release handle 6 feet (1.8 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 control console:
• 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
control console.
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.
13. To avoid SERIOUS PERSONAL INJURY or DEATH from
electrocution, disconnect ALL electric and battery power
BEFORE performing ANY service or maintenance.