LiftMaster 8550W 8550W Users Guide Manual - Page 11

Adjustment Introduction Without a properly installed safety reversal system, persons (particularly small children) could be SERIOUSLY INJURED or KILLED by a closing garage door. • Incorrect adjustment of garage door travel limits will interfere with proper operation of safety reversal system. • 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 2x4 laid flat) on floor. Your garage door opener is designed with electronic controls to make setup and adjustments easy. The adjustments allow you to program where the door will stop in the open (UP) and close (DOWN) position. The electronic controls sense the amount of force required to open and close the door. NOTE: If anything interferes with the door's upward travel it will stop. If anything interferes with the door's downward travel, it will reverse. To prevent damage to vehicles, be sure fully open door provides adequate clearance. Programming Buttons The programming buttons are located on the left side panel of the garage door opener and are used to program the travel. UP Button Adjustment Button DOWN Button 11