Chamberlain LiftMaster PROFESSIONAL SECURITY+ 1280LMC-R Manuel Du Propriétaire page 13

INSTALLATION STEP 5
Hang the Opener
Two representative installations are shown. Yours
may be different. Hanging brackets should be angled
(Figure 1) to provide rigid support. On finished
ceilings (Figure 2), attach a sturdy metal bracket to
structural supports before installing the opener. This
bracket and fastening hardware are not provided.
1. Measure the distance from each side of the motor
unit to the structural support.
2. Cut both pieces of the hanging bracket to required
lengths.
3. Drill 3/16" pilot holes in the structural supports.
4. Attach one end of each bracket to a support with
5/16"-18x1-7/8" lag screws.
5. Fasten the opener to the hanging brackets with
5/16"-18x7/8" hex screws, lock washers and nuts.
6. Check to make sure the rail is centered over the
door (or in line with the header bracket if the
bracket is not centered above the door).
7. Remove the 2x4. Operate the door manually. If
the door hits the rail, raise the header bracket.
8. Grease the top and underside of the rail surface
where the trolley slides with rail grease.
HARDWARE SHOWN ACTUAL SIZE
Lag Screw 5/16"-18x1-7/8"
Hex Screw
5/16"-18x7/8"
Lock Washer 5/16"
Nut 5/16"-18
WARNING
To avoid possible SERIOUS INJURY from a falling
garage door opener, fasten it SECURELY to structural
CAUTION
supports of the garage. Concrete anchors MUST be used
if installing any brackets into masonry.
Figure 1
Measure
Distance
5/16"-18x7/8"
Hex Screws
5/16" Lock
Washers
5/16"-18 Nuts
Figure 2
— FINISHED CEILING —
Bracket
(Not provided)
5/16"-18x7/8" Screw
5/16" Lock Washer
5/16"-18 Nut
13
Structural
Supports
Lag Screws
5/16"-18x1-7/8"
Hidden
Support
Lag Screws
5/16"-18x1-7/8"
(Not provided)
5/16"-18x7/8" Screw
5/16" Lock Washer
5/16"-18 Nut