Chamberlain 1120E-1/2HP Owner's Manual page 25

ADJUSTMENT STEP 3
Test Safety Reverse System
GARAGE DOOR INSTALLATION
Place a 25mm obstacle on the floor under the
garage door. Operate door in DOWN direction. The
door MUST reverse on the obstruction.
If the door stops on the obstruction, it is not traveling
far enough in the down direction. Increase the
DOWN limit by turning DOWN limit adjustment
screw counterclockwise 1/4 turn. Repeat test.
On a sectional door, make sure limit
adjustments do not force the door arm beyond a
straight up and down position. See the
illustration on Page 21.
When the door reverses on the 25mm obstacle,
remove the obstruction and run the opener through
3 or 4 complete travel cycles to test the adjustment.
Door MUST NOT reverse in closed position.
GATE INSTALLATION
1. The opener must reverse if the gate comes in
contact with an obstruction. A closing gate should
reverse with little effort, and open completely.
Refer to Adjustment Step 2 in Owners Manual
for instructions.
2. At completion of installation of opener and testing
of reversing feature in #1 above, the 25mm
reversal test must be completed. (Use 25mm
board laid flat against the wall or gate edge.)
a) On a sliding gate door, place a 25mm board
between the door and wall of a closing gate.
Gate must reverse on the board and open
completely. Repeat at opposite wall if two
openers are installed.
b) On a swing out gate, insert a 25mm board
between the closing gate sections. Gate
sections must reverse and swing open
completely.
c) If the gate stops on the obstruction, it is not
traveling far enough in the closing direction.
Increase the DOWN limit adjustment screw
counterclockwise 1/4 turn. Repeat test.
d) When the gate reverses on a 25mm board,
remove the obstruction and run the opener
through complete travel cycle to test
adjustment.
e) If the gate will not reverse after repeated
adjustment attempts, call for professional
gate service.
Failure to test and adjust the safety
reverse system may result in serious
injury or death to persons trapped by a
closing garage door. Repeat this test
once a month and adjust as needed.
Important safety check
Repeat Adjustment Steps 1, 2 and 3 after:
• Each adjustment of door arm length, force
controls or limit controls.
• Any repair to or adjustment of the garage door
(including springs and hardware).
• Any repair to or buckling of the garage floor.
• Any repair to or adjustment of the opener.
SECTIONAL DOOR
25mm Obstacle
SLIDING GATE
25mm
Obstacle
SWINGING GATE
25
ONE-PIECE DOOR
25mm Obstacle
25mm Obstacle