Chamberlain WHISPER DRIVE HD900D - Manual (Page 3)

3
To prevent damage to garage door and opener:
• ALWAYS disable locks BEFORE installing and operating the
opener.
• ONLY operate garage door opener at 120V, 60 Hz to avoid
malfunction and damage.
To prevent possible SERIOUS INJURY or DEATH:
• ALWAYS call a trained door systems technician if garage
door binds, sticks, or is out of balance. An unbalanced
garage door may not reverse when required.
• NEVER try to loosen, move or adjust garage door, door
springs, cables, pulleys, brackets or their hardware, ALL of
which are under EXTREME tension.
• Disable ALL locks and remove ALL ropes connected to
garage door BEFORE installing and operating garage door
opener to avoid entanglement.
Preparing your garage door
Before you begin:
• Disable locks.
• Remove any ropes connected to garage door.
• Complete the following test to make sure your garage door is
balanced and is not sticking or binding:
1. Lift the door about halfway as shown. Release the door. If
balanced, it should stay in place, supported entirely by its
springs.
2. Raise and lower the door to see if there is any binding or
sticking.
If your door binds, sticks, or is out of balance, call a trained door
systems technician.
Tools needed
During assembly, installation and adjustment of the opener,
instructions will call for hand tools as illustrated below.
Pliers
Wire Cutters
Claw Hammer
Hack Saw
Screwdriver
Adjustable End Wrench
Sockets and Wrench
1/2", 5/8", 7/16", 9/16"
and 1/4"
Drill
Tape Measure
2 1
Stepladder
Pencil
Drill Bits
3/16", 5/16"
and 5/32"
Carpenter’s
Level (optional)
2 1
Sectional Door
One-Piece Door