Chamberlain 1200 - Manual (Page 29)

Adjustment Step 2
Adjust the Force
Too much force on the door will interfere with
the proper operation of the safety reverse
system.
The door might not reverse properly
when required and could seriously injure or
kill someone under it. Do not increase the
force beyond the minimum amount required to
close the door. Do not use the force
adjustments to compensate for a binding or
sticking garage door. Test the safety reverse
system following all adjustments to force
levels. See page 30.
Force adjustment controls are located on the back
panel of the opener. Force adjustment settings
regulate the amount of power required to open and
close the door.
The door will stop in the up direction if anything
interferes with its travel. The door will reverse in the
down direction if anything interferes with its travel
(including binding or unbalanced doors).
If the forces are set too light, door travel may be
interrupted by
nuisance reversals in the down
direction and stops in the up direction. Weather
conditions can affect the door movement, so
occasional adjustment may be needed.
The maximum force adjustment range is
260 degrees, about 3/4 of a complete turn. Do not
force controls beyond that point. Turn force
adjustment controls with a screwdriver.
Force
Adjustment
Controls
Back Panel
of Opener
KG KG
1
3
9
7 5
1
3
9
7 5
1 2 3
How and When to Adjust the Forces
Test the DOWN (close) force:
Grasp the door bottom when the door is about
halfway through DOWN (close) travel. The door
should reverse. (Reversal halfway through down
travel does not guarantee reversal on a two-inch
obstruction. See page 30.) If the door is hard to
hold or doesn't reverse, decrease the DOWN (close)
force by turning the control counterclockwise.
Make 10 degree turn adjustments until the door
reverses normally. After each adjustment, run the
opener through a complete cycle.
Test the UP (open) force:
Grasp the door bottom when the door is about
halfway through UP (open) travel. The door should
stop. If the door is hard to hold or doesn't stop,
decrease UP (open) force by turning the control
counterclockwise.
Make 10 degree turn adjustments until the door stops
easily. After each adjustment, run the opener through
a complete travel cycle.
If the door doesn't open at least 5 feet:
Increase UP (Open) force by turning the control
clockwise. Make 10 degree turn adjustments until
door opens completely. Re-adjust the UP limit if
necessary. After each adjustment, run the opener
through a complete travel cycle.
If the door reverses during the down (close) cycle
and the opener lights aren't flashing:
Increase DOWN (close) force by turning the control
clockwise. Make 10 degree turn adjustments until the
door completes a close cycle. After each adjustment,
run the opener through a complete travel cycle. Do
not increase the force beyond the minimum
amount required to close the door.
29
Adjustment Label
KG KG
1
3
9
7
5
1
3
9
7
5
WARNING