Chamberlain LiftMaster PROFESSIONAL SECURITY+ 3255-2CM Manuel Du Propriétaire page 22

ALL ONE-PIECE DOORS
1. Assemble the door arm, Figure 4:
• Fasten the straight and curved door arm sections
together to the longest possible length (with a 2 or 3
hole overlap).
• With the door closed, connect the straight door arm
section to the door bracket with the 5/16"x1-1/4" clevis
pin.
• Secure with a ring fastener.
2. Adjustment procedures, Figure 5:
• On one-piece doors, before connecting the door arm
to the trolley, the travel limits must be adjusted. Limit
adjust ment screws are located on the left side panel
as shown on page 23. Follow adjustment procedures
below.
• Open door adjustment: decrease UP travel limit
- Turn the UP limit adjustment screw counter-clockwise
4 turns.
- Press the Door Control push button. The trolley will
travel to the fully open position.
- Manually raise the door to the open position (parallel
to the floor), and lift the door arm to the trolley. The
arm should touch the trolley just in back of the door
arm connector hole. Refer to the fully open trolley/
door arm positions in the illustration. If the arm does
not extend far enough, adjust the limit further. One
full turn equals 2" (5 cm) of trolley travel.
• Closed door adjustment: decrease DOWN travel
limit
- Turn the DOWN limit adjustment screw clockwise
4 complete turns.
Figure 5
Inner Trolley
Outer Trolley
Door Arm
Connector Hole
Door Arm
Closed
Door
Inner Trolley
Correct Angle
Open Door
Door
Bracket
Clevis Pin
Straight
5/16"x1-1/4"
Arm
Bolts
5/16"-18x7/8
Figure 4
- Press the Door Control push button. The trolley will
travel to the fully closed position.
- Manually close the door and lift the door arm to the
trolley. The arm should touch the trolley just ahead of
the door arm connector hole. Refer to the fully closed
trolley/door arm positions in the illustration. If the arm
is behind the connector hole, adjust the limit further.
One full turn equals 2" (5 cm) of trolley travel.
3. Connect the door arm to the trolley:
• Close the door and join the curved arm to the
connector hole in the trolley with the remaining clevis
pin. It may be necessary to lift the door slightly to make
the connection.
• Secure with a ring fastener.
• Run the opener through a complete travel cycle. If the
door has a slight "backward" slant in full open position
as shown in the illustration, decrease the UP limit until
the door is parallel to the floor.
NOTE: When setting the up limit on the following page, the
door should not have a "backward" slant when fully open
as illustrated below. A slight backward slant will cause
unnecessary bucking and/or jerking operation as the door
is being opened or closed from the fully open position.
Emergency Release Handle
Door Arm
Door with
Backward Slant (Incorrect)
22
Ring
Fastener
Nuts
Lock
5/16"-18
Washers
5/16"
Outer Trolley
Curved
Door Arm