Chamberlain 1145-1/3HP Garage Door Opener User Manual


 
INSTALLATION STEP 4
Hang the Opener
THE OPENER MUST BE SECURELY
FASTENED TO A STRUCTURAL SUPPORT
OF THE GARAGE.
Three representative installations are shown. Yours may be different. Hanging brackets should
be angled (Fig.1) or crossed (Fig.2) to provide rigid support. On finished ceilings (Fig.3), attach a
sturdy metal bracket (not supplied) to ceiling joists before installing opener.
PROCEDURE: Measure the distance from EACH side of
the opener to the structural support.
Cut both pieces of the hanging bracket to required
lengths. Flatten one end of each bracket and bend or
twist to fit the fastening angles. Do not bend at the
bracket holes. Drill 3/16" pilot holes in structural
supports. Attach flattened ends of brackets to the
supports with 5/16"x1-7/8" lag screws.
Lift opener and fasten to hanging bracket as shown.
Check to make sure the T-rail is centered over
door. REMOVE the 2x4.
Operate the door manually. If door hits the rail, raise
header bracket.
Grease the top and underside of rail surface on
which trolley slides. A tube of grease is supplied.
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