9.3Attach the curved door armto the door bracketusing the clevispin.Attach with the ring fastener. . The 8355W ½ HP Belt Drive Opener is the perfect choice if you want both quiet and smooth-running reliability, or simply have rooms positioned above your garage. . Incorrectadjustmentofgarage door travel limitswill interfere with proper operation of safetyreversal system. . 1.7 Remove the door control fromthe wall and drill a 5/32 inch (4 mm) hole for the top screw. . 1.2A DO NOT run garage door opener at this time. Position the beltaround the garage door opener sprocket. •Disable ALL locksand remove ALL ropes connected to garage door BEFORE installation and operating garage door opener to avoid entanglement. As more convenient features, this opener also is equipped with built-in MyQ® technology that lets you monitor and control your garage door and house lights remotely by using a computer or smartphone with the available LiftMaster Internet Gateway. NEVERpermitchildren to operate or playwith door control push buttonsor remote control transmitters. . Remove the packing material and liftthe garage door opener onto a ladder. Wheninstallingthe safety reversingsensors check the following: •Sensorsare installed inside the garage,one on either side ofthe door. Extend the line onto the header wall above the door. •ONLY operate garage door opener at 120 V,60 Hzto avoid malfunction and damage. ■ This garage door opener is ONLY compatible with MyQ® and Security 2.0™, ■ ONLY enable the Timer-to-Close* or MyQ® remote operation feature* when, the garage door opener is installed on a sectional door. . . 2.1Run the white and red/white wire fromthe door control to the garage door opener.Attach the wire to the wall and ceiling with the staples(notapplicable for gang boxor pre-wired installations).Do notpierce the wire with the staple asthismaycause a shortor an open circuit. . . 5.4Attach one end ofeach bracketto a supportwith 5/16"- 18x1-7/8" lag screws(notprovided). . The model LiftMaster 8355W door operator is manufactured by Chamberlain Group. . . 6.Mountthe emergencyrelease within reach,butatleast6 feet(1.83 m) above the floor and avoiding contactwith vehiclesto avoid accidental release. Remove the door control fromthe wall and drill a 5/32 inch (4 mm) hole for the top screw. ONLY enable the Timer-to-Close* or MyQ ® remote operation feature* when the garage door opener is installed on a sectional door. . . Liftthe door halfwayup.Release the door.Ifbalanced,itshould stayin place,supported entirelybyitssprings. . •NEVERuse handle to pull door open or closed.Ifrope knotbecomesuntied,you could fall. . . . Measure the distance fromeach side ofthe motor unitto the structural support. NEVERuse emergencyrelease handle unlessgarage doorwayisclear ofpersonsand obstructions. 3.ALL repairsto cables,spring assembliesand other hardware MUSTbe made bya trained door systemstechnician BEFORE installing opener. 26, Features . . Disable locksand remove anyropes connected to the garage door. Commercial & Industrial maintenance & repair services, < Go back to Residential garage door opener models. . Pull the emergencyrelease handle toward the garage door opener until the trolleyrelease armishorizontal.The trolleywill. • The Protector System® has safety sensors that project a light beam across the garage door opening, automatically reversing the door if anything interrupts the beam. (Not Provided) Lag Screws 5/16"- 18x1-7/8", Hex Bolt 5/16"- 18x7/8", Lock Washer 5/16", Nut 5/16"-18. . You can attach the header bracketeither to the wall above the garage door,or to the ceiling. Be sure power isNOTconnected to the garage door opener BEFORE installing the safety reversing sensor. . 12.Upon completion ofinstallation,testsafetyreversal system.Door MUSTreverse on contactwith a 1-1/2"(3.8 cm) high object(or a 2x4 laid flat) on the floor. The instructions for these accessories will be attached to the accessory and are not included in this manual. . . Do notuse LEDbulbsastheymayreduce the range or performance ofyour remote control(s). . Strip 7/16 inch (11 mm) ofinsulation from one end ofthe wire and separate the wires. . . When wiring the door control to the garage door opener make sure you use the same wiresthatare connected to the door control. To preventpossible SERIOUS INJURY or DEATH: •ALWAYS call a trained door systems technician ifgarage door binds,sticks,or is outofbalance.An unbalanced garage door mayNOTreverse when required. Activate door ONLY when itcan be seen clearly,isproperlyadjusted,and there are no obstructionsto door travel. . Instructionsbeloware for attaching the garage door opener directlyto structural supports. To avoid installation difficulties, do not activate the garage door opener at this time. Project an invisible light beam across the garage door opening and automatically reverse the door if anything interrupts the beam while the door is going down. . . 2.1A Center the bracketon the vertical centerline with the bottomedge ofthe bracketon the horizontal line asshown (with the arrowpointing toward the ceiling). •Concrete anchorsMUSTbe used if mounting header bracketor 2x4 into masonry. .