Chamberlain SECURITY 3275C - Manuel (Page 24)

24
ADJUSTMENT STEP 2
Adjust the Force
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" (3.8 cm) obstruction. See Adjustment Step 3, page 25.
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.
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" high (3.8 cm) object (or 2x4 laid flat) on floor.
FORCE ADJUSTMENT LABEL
KG KG
1
3
9
7
5
1
3
9
7
5
Antenna
Open Force Close Force
Back Panel
KG
KG
1
3 9
7 5
1
3 9
7 5
Force Adjustment Controls