Chamberlain 2000SDR 1/2 HP - Manual (Page 15)

Installation Step 5
Position the Opener
Follow instructions which apply to your door
type as illustrated. To prevent damage to steel, alumin um, fiberglass or
glass panel doors, do not rest the opener on the door
without using a 2x4.
SECTIONAL Door or
ONE-PIECE Door with Track
A 2x4 laid flat is convenient for setting an ideal door-
to-rail distance.
• Raise the opener onto a stepladder.
You will need help at this point if the ladder is not tall
enough.
• Open the door all the way and place a 2x4 laid flat on
the top section beneath the rail.
If the top panel hits the trolley when you raise the door,
pull down on the trolley release arm to disconnect the
inner and outer sections. The trolley can remain
disconnected until Step 12 is completed.
Rail 2x4
Door
Top of Opener
Header
Bracket
The Chamberlain Group, Inc.
Step 3 Position Opener Chassis
114A1794 Lift-Master One Piece Rail
5/9/94 - 6/1/94, 6/8/94 - 10/20/94
Top of Door
Foam
Packaging
Foam
Packaging
ONE-PIECE Door without Track
• With the door fully open and parallel to the floor,
measure the distance from the floor to the top of the
door.
• Using a stepladder as a support, raise the opener to the
same distance as the door from the floor (it will be at a
slight angle as shown).
• The top of the door should be level with the top of the
opener. Do not position the opener more than 3" above
this point.
Rail 2x4
Door
Top of Opener
Header
Bracket
The Chamberlain Group, Inc.
Step 3 Position Opener Chassis
114A1794 Lift-Master One Piece Rail
5/9/94 - 6/1/94, 6/8/94 - 10/20/94
Top of Door
Foam
Packaging
Foam
Packaging
15
WARNING
CAUTION
WARNING
The Chamberlain Group, Inc.
Manual Disconnect
Liftmaster Screw Drive #114A1794
6/2/94, 6/15
NOTICE
Manual
Release
Handle
(Pull at 45° angle)
Trolley
Trolley
Trolley
Release Arm
NOTICE
Trolley
ReleaseArm
(in Manual
Disconnect
Position)
Trolley
Trolley
Release Arm