Chamberlain 3850 Garage Door Opener User Manual


 
12
INSTALLATION STEP 5
Hang the Opener
Three representative installations are shown. Yours may
be different. Hanging brackets should be angled
(Figure 1) to provide rigid support. On finished ceilings
(Figure 2 and Figure 3), attach a sturdy metal bracket to
structural supports before installing the opener. This
bracket and fastening hardware are not provided.
1.Remove foam packaging. 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 bolts, 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.
NOTE: DO NOT connect power to opener at this time.
To avoid possible SERIOUS INJURY from a falling garage
door opener, fasten it SECURELY to structural supports of
the garage. Concrete anchors MUST be used if installing ANY
brackets into masonry.
Hex Bolt
5/16"-18x7/8"
Nut 5/16"-18
Lock Washer 5/16"
Lag Screw 5/16"-9x1-5/8"
HARDWARE SHOWN ACTUAL SIZE
Measure
Distance
Lag Screws
5/16"-18x1-7/8"
Structural
Supports
Bracket
(Not Provided)
Lag Screws
5/16"-18x1-7/8"
(Not Provided)
Bolt 5/16"-18x7/8"
Lock Washer 5/16"
Nut 5/16"-18
— FINISHED CEILING —
Hidden
Support
Bolt 5/16"-18x7/8"
Lock Washer 5/16"
Nut 5/16"-18
Bolt 5/16"-18x7/8"
Lock Washer 5/16"
Nut 5/16"-18
Bolt 5/16"-18x7/8"
Lock Washer 5/16"
Nut 5/16"-18
Lag Screws
5/16"-18x1-7/8"
(Not Provided)
Bolt 5/16"-18x7/8"
Lock Washer 5/16"
Nut 5/16"-18
FINISHED CEILING
Figure 1
Figure 2
Figure 3
WARNING
CAUTION
WARNING
WARNING