LiftMaster APT APT LOGIC 3 Manual - Page 10

ADJUSTMENT BRAKE ADJUSTMENT The solenoid brake is adjusted at the factory and should not need additional adjustment for the life of the brake assembly. Replace brake assembly when necessary. Refer to the illustration for identification of components for the solenoid type brake system. Solenoid Cotterpin Release Lever Brake Assembly Brake Plate Assembly CLUTCH ADJUSTMENT AND AUXILIARY REVERSAL SYSTEM The Auxiliary Reversal System is designed to protect the door and motorized operator. It is NOT a substitute for a safety sensing device. The Auxiliary Reversal System works in tandem with the adjustable clutch to detect if a closing door runs into or comes across an obstruction. If an obstruction is met and causes the clutch to slip, the Auxiliary Reversal System will return the door to the full open position when closing or stops the door when opening. 1. Remove cotterpin from nut on the clutch shaft. 2. Back off clutch nut until there is very little tension on the clutch spring. 3. Tighten clutch nut gradually until there is just enough tension to permit the operator to move the door smoothly but to allow the clutch to slip if the door is obstructed. When the clutch is properly adjusted, it should generally be possible to stop the door by hand during travel. 4. Reinstall cotterpin. WARNING To prevent possible SERIOUS INJURY or DEATH, install CAUTION reversing sensors when the 3-button control station is out of sight of the door or ANY other control (automatic or manual) is used. Reversing devices are recommended for ALL installations. Adjusting Nut Spring Clutch Pad Clutch Plate Cotterpin Washer Clutch Pulley 10