Chamberlain Security+ 3900PLD - Manual (Page 6)

ASSEMBLY STEP 1
Attach the Collar to the Operator
To avoid installation difficulties, do not run the door
operator until instructed to do so.
• Loosen the collar screws.
• Attach collar to either the left or the right side of the
operator. Ensure that the collar is seated all the way on
motor shaft until stop is reached (Figure 1).
• Position the collar so that the screws are facing up
(accessible when attached to the torsion bar).
• Tighten both sides of collar screws equally to secure
collar to the motor unit (12-14 ft./lbs. of torque)
(Figure 2).
NOTE: For most installations the screws should be facing
up for easy access. Do not tighten set screws until
indicated.
6
Collar Screw
Collar Screw
Set Screw
ASSEMBLY STEP 2
Attach Mounting Bracket
to the Operator
• Loosely attach slotted side of mounting bracket to the
same side of the operator as the collar, using
self-threading screws provided.
NOTE: Do not tighten until instructed. Illustrations shown
are for left side installation.
Socket Wrench
Figure 1
RIGHT WRONG
Figure 2
Screw
#10-32
HARDWARE SHOWN ACTUAL SIZE
To prevent possible SERIOUS INJURY or DEATH, the collar
MUST be properly tightened. The door may not reverse
correctly or limits may be lost due to collar slip.