LiftMaster 85503 8550W 8550WL 8550WLB 8550WLB-267 8557W 8587W WLED WLED-267 85 - Page 11

Operation The Protector System® (Safety Reversing Sensors) Be sure power is NOT connected to the garage door opener BEFORE installing the safety reversing sensor. To prevent SERIOUS INJURY or DEATH from closing garage door: l Correctly connect and align the safety reversing sensor. This required safety device MUST NOT be disabled. l Install the safety reversing sensor so beam is NO HIGHER than 6" (15 cm) above garage floor. The door will not close if the sensors have not been installed and aligned correctly. When the light beam is obstructed or misaligned while the door is closing, the door will reverse and the garage door opener lights will flash ten times. If the door is already open, it will not close. The sensors can be aligned by loosening the wing nuts, aligning the sensors, and tightening the wing nuts. Check to make sure the LEDs in both sensors are glowing steadily. The LEDs in both sensors will glow steadily if they are aligned and wired correctly. (invisible light beam) Wing Nut Amber LED SENDING SENSOR Safety Reversing Sensor 6" (15 cm) max. above floor Green LED RECEIVING SENSOR Wing Nut Safety Reversing Sensor 6" (15 cm) max. above floor If the amber LED on the sending sensor is not glowing: 1. Make sure there is power to the garage door opener. 2. Make sure the sensor wire is not shorted/broken. 3. Make sure the sensor has been wired correctly: White wires to white terminal and white/black wires to gray terminal. If the green LED on the receiving sensor is not glowing: 1. Make sure the sensor wire is not shorted/broken. 2. Make sure the sensors are aligned. 11