LiftMaster MJ MJ (BLACK LINE) Manual - Page 4

INSTALLATION Important NOTE: Before your operator is installed, be sure the door has been properly aligned and is working smoothly. The operator may be wall mounted or mounted on a bracket or shelf. If necessary, refer to the operator preparations on page 3. Refer to the illustration and instructions below that suits your application. 1a. Wall Mounting The operator should generally be installed below the door shaft, and as close to the door as possible. The optimum distance between the door shaft and operator drive shaft is between 12" - 15" (Figure 3). 1b. Bracket or Shelf Mounting The operator may be mounted either above or below the door shaft. The optimum distance between the door shaft and operator drive shaft is between 12" - 15" (Figure 4). OPTIONAL Mounting Bracket P/N 1008-90958 Optimum Distance 12 - 15" Optimum Distance 12 - 15" Typical Right Hand Wall Mounted Operator FIGURE 3 IMPORTANT: The shelf or bracket must provide adequate support, prevent play between operator and door shaft, and permit operator to be fastened securely and with the drive shaft parallel to the door shaft. FIGURE 4 1c. Place door sprocket on the door shaft. Do not insert the key at this time. 2. Place drive sprocket on the appropriate side of the operator. Do not insert the key at this time. 3. Wrap drive chain around door sprocket and join roller chain ends together with master link. 4. Raise operator to approximate mounting position and position chain over operator sprocket. 5. Raise or lower operator until the chain is taut (not tight). Make sure the operator output shaft is parallel to door shaft and sprockets are aligned. When in position, secure the operator to wall or mounting bracket. 6. Align sprockets and secure (Figure 5). 4 Be sure door sprocket is properly aligned with drive before securing to the shaft. Chain Retaining Bracket FIGURE 5