LiftMaster 3800 3800 Manual - Page 19

ADJUSTMENT STEP 3 Test the Safety Reversal System TEST • With the door fully open, place a 1-1/2" (3.8 cm) board (or 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. Upon successful safety reversal test proceed to Adjustment Step 4. ADJUST • If the door stops on the obstruction, it is not traveling far enough in the down direction. Complete Adjustment Steps 1 and 2 Programming the Limits and Forces. • Repeat the test. • When the door reverses on the 1-1/2" (3.8 cm) board (or 2x4 laid flat), remove the obstruction and run the opener through 3 or 4 complete travel cycles to test adjustment. • If the unit continues to fail the Safety Reverse Test, call for a trained door systems technician. IMPORTANT SAFETY CHECK: Test the Safety Reverse System after: • Each adjustment of limits, or force 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. ADJUSTMENT STEP 4 Test The Protector System® • Press the remote control push button to open the door. • Place the opener carton in the path of the door. • Press the remote control push button to close the door. The door will not move more than an inch, and the opener lights will flash. The garage door opener will not close from a remote if the indicator light in either sensor is off (alerting you to the fact that the sensor is misaligned or obstructed). If the opener closes the door when the safety reversing sensor is obstructed, do not operate the door. Call for a trained door systems technician. WARNING Without a properly installed safety reversal system, persons CAUTION (particularly small children) could be SERIOUSLY INJURED or KILLED by a closing garage door. • Safety reversal system MUST be tested every month. • 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" (3.8 cm) high object (or 2x4 laid flat) on the floor. 1-1/2" (3.8 cm) board (or a 2x4 laid flat) WARNING Without a properly installed safety reversing sensor, persons CAUTION (particularly small children) could be SERIOUSLY INJURED or KILLED by a closing garage door. Safety Reversing Sensor Safety Reversing Sensor 19