Master Lock ATS 211 - Manual (Page 23)

Adjustment Step 4
Test the Safety Reverse System
Test:
• Place a 2x4 laid flat on the floor, centered under
the garage door.
• Operate the door in the down direction. The door
must reverse on striking the obstruction.
Adjustment:
If the door stops on the obstruction, it is not traveling
far enough in the down direction.
• Increase the DOWN limit by turning the DOWN
limit adjustment screw counterclockwise 1/4 turn.
• Repeat the test.
Make sure limit adjustments do not force the
door arm beyond a straight up and down
position. See the illustration on page 20.
• When the door reverses on the 2x4, remove the
obstruction and run the opener through 3 or 4
complete travel cycles to test adjustment.
If the door will not reverse after repeated
adjustment attempts, call for professional
garage door service.
GARAGE DOOR
2x4 Laid Flat
Failure to test and adjust the safety reverse
system may result in serious injury or death
from a closing garage door. Repeat this test
once a month and adjust as needed.
23
Adjustment Step 3
Test The Safety Reversing Sensor
• Press the Door Control push button to open the
door.
• Place the opener carton in the path of the door.
• Press the Door Control push button to close the
door. The door will not move more than an inch,
and the opener light(s) will flash.
The garage door opener will not close from a
remote control transmitter if the indicator light
in either sensor is
off (alerting you to the fact
that the sensor is misaligned or obstructed).
The garage door can be closed by pressing and
holding the Door Control push button until down
travel is completed.
Professional service is required if the opener
closes the door when the safety reversing
sensor is obstructed.
Safety Reversing Sensor Safety Reversing Sensor
Without a properly working safety reversing
sensor, persons (particularly children) could
be seriously injured or killed by a closing
garage door. Repeat this test once a month.
Important safety check
Repeat Adjustment Steps 1, 2 and 4 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.
WARNING
WARNING