5IMPORTANT PRE-ASSEMBLY CHECKIf assembling a motor head unit from a factory sealed box skip this check.Every Power Head Unit is factory tested and shipped withthe limit switch adjustment in the door CLOSED position.If the Motor Power Head Unit has been powered up beforeassembly, perform the following steps to insure that thelimit switch adjustment is in the door CLOSED position.Connect Motor Head Unit to a power source and shortacross the screw terminals labeled “PB” and “COM” witha metal screw driver.Motor should start; run through a full OPEN cycle, and stop.This will leave Motor Power Head Unit in OPEN position.To get Motor Power Head Unit back to full CLOSE position,short and hold motor terminals again. Continue to shortterminals until Motor Power Head Unit stops in theCLOSED position. Disconnect from power source andproceed to assembly.Before you begin, complete the following two tests to insure that the door is balanced and working properly. A door thatbinds, sticks or is out of balance could cause severe injury. Do not attempt to compensate for an improperly adjusted doorby the installation of an opener. This will interfere with the proper operation of the opener mechanism and/or may damagethe door. Have a qualified service person make any needed adjustments or repairs to cables, spring assemblies and otherhardware before proceeding with installation.Door Test OneRaise and lower the door and check closely for anysticking or binding that occurs.Lift the door approximately half way open, as illustrated.When releasing the door, it should stay in position. Ifspring pressure pulls the door further open or doorweight pulls it further down, your door is not properlyadjusted.Door Test TwoWhen properly installed, a door should remain clear ofthe opening, when allowed to rest at its natural, full openposition.If “door drift” pulls door back into opening or spring ten-sion is not sufficient to pull door totally clear of opening,the door is not properly adjusted.Door Tests Before Starting