Chamberlain Security+ 3900PLD - Manual

Owner’s Manual
■ Please read this manual and the enclosed safety materials carefully!
■ Fasten the manual near the door after installation.
■ The door WILL NOT CLOSE unless The Protector System ® and cable tension monitor are
connected and properly aligned.
■ Periodic checks of the operator are required to ensure safe operation.
■ The model number label is located behind the hinged door of your operator.
■ Do NOT exceed 10 complete cycles of door operation per hour.
DOOR OPERATOR
Model 3900PLD
For Light Duty Commercial Use Install On
Sectional Doors With Torsion Assemblies Only
The Chamberlain Group, Inc.
845 Larch Avenue
Elmhurst, Illinois 60126-1196
www.liftmaster.com
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Serial #
Installation Date
2 Y E A R W A R R A N T Y