Adjust The Forces - Chamberlain Power Drive Assembly & Installation Manual

ADJUSTMENT STEP 2

ADJUST THE FORCES

Force adjustment controls are located on the back panel
of the motor unit. Force adjustment settings regulate the
amount of power required to open and close the door.
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 about 3/4 of a
complete turn. Do not force controls beyond that point.
Turn force adjustment controls with a screwdriver.
NOTE: If anything interferes with the door's upward travel,
it will stop. If anything interferes with the door's downward
travel (including binding or unbalanced doors), it will
reverse.
HOW AND WHEN TO ADJUST THE FORCES
1. 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 1-1/2
Adjustment Step 3, page 22. If the door is hard to
hold or doesn't reverse, decrease the DOWN (close)
force by turning the control counterclockwise. Make
small adjustments until the door reverses normally. After
each adjustment, run the opener through a complete
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
small 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.
2. 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 small adjustments until the door stops easily and
opens fully. After each adjustment, run the opener
through a complete travel cycle.
• If the door doesn't open at least 5 feet (1.5 m),
increase UP (open) force by turning the control
clockwise. Make small adjustments until door opens
completely. Readjust the UP limit if necessary. After
each adjustment, run the opener through a complete
travel cycle.
"
(3.8 cm) obstruction. See
Without a properly installed safety reversal system, persons
(particularly small children) could be SERIOUSLY INJURED or
KILLED by a closing garage door.
• Too much force on garage door will interfere with proper
operation of safety reversal system.
• NEVER increase force beyond minimum amount required to
close garage door.
• NEVER use force adjustments to compensate for a binding or
sticking garage door.
• If one control (force or travel limits) is adjusted, the other
control may also need adjustment.
• After ANY adjustments are made, the safety reversal system
must be tested. Door must reverse on contact with 1-1/2"
(3.8 cm) high object (or 2 x 4 laid flat) on floor.
FORCE ADJUSTMENT LABEL
9
7
Open Force
Force Settings:
1 = Lowest Force
9 = Maximum Force
21
WARNING
CAUTION
Force Adjustment
Controls
KG KG
Back Side Panel
9
1 1
3 7 3
5 5
KG
KG
Close Force