Adjustment; Program The Travel Limits - Chamberlain Liftmaster Security+ 3900PLD Owner's Manual

ADJUSTMENT STEP 1

Program the Travel Limits

Travel limits regulate the points at which the door will
stop when moving up or down.
Adjust the position of the door by using the black and
purple buttons. Black moves the door UP (open) and
purple moves the door DOWN (close).
LED
Figure 1
Purple
Button
Setting the UP position:
1. Press and hold the black button until the LED starts
flashing slowly, then release (Figure 2).
2. Push and hold the black button until the door reaches
the desired UP (open) position.
NOTE: Make sure the door opens high enough for your
vehicle.
3. Push the door control or programmed remote control.
This sets the UP (open) limit and begins closing the
door (Figure 3).
4. Immediately when the door begins to close, press and
release either the black or purple button. This will stop
the door.
Setting the DOWN position:
5. Push and hold the purple button until the door reaches
the desired DOWN (closed) position.
6. Once the door is closed, if there appears to be too
much pressure on the door, you may toggle the door
back and forth using the black and purple buttons to
reach the desired closed position.
7. Push the door control or programmed remote control.
This sets the DOWN (close) limit and the door should
open.
Proceed to Set the Force.
Black
Button
Without a properly installed safety reversal system, persons
(particularly small children) could be SERIOUSLY INJURED or
KILLED by a closing door.
• NEVER learn forces or limits when door is binding or
sticking. Repair door first.
• Incorrect adjustment of door travel limits will interfere with
proper operation of safety reversal system.
• After ANY adjustments are made, the safety reversal system
MUST be tested. Door MUST reverse on contact with 1-1/2"
high (3.8 cm) object (or 2x4 laid flat) on floor.
To prevent damage to vehicles, be sure fully open door
provides adequate clearance.
Figure 2
Push and hold
until the door
is at desired UP
position
Figure 3
Figure 4
BLACK
PURPLE
17
BLACK
PURPLE
Push either
button to stop
door at desired
DOWN position