LiftMaster MJ MJ (BLACK LINE) Manual - Page 3

NING IMPORTANWT ASARFNEITNYGNOTES ION WARNING To prevent possible SERIOUS INJURY or DEATH: • DO NOT connect electric power until instructed to do so. • If the door lock needs to remain functional, install an interlock switch. • ALWAYS call a trained professional door serviceman if door binds, sticks or is out of balance. An unbalanced door may not reverse when required. • NEVER try to loosen, move or adjust doors, door springs, cables, pulleys, brackets or their hardware, ALL of which are under EXTREME tension and can cause SERIOUS PERSONAL INJURY. • Disable ALL locks and remove ALL ropes connected to door BEFORE installing and operating door operator to avoid entanglement. PREPARATION It is imperative that the wall or mounting surface provide adequate support for the operator. This surface must: a. Be rigid to prevent play between operator and door shaft. b. Provide a level base. c. Permit the operator to be fastened securely and with the drive shaft parallel to the door shaft. The safety and wear of the operator will be adversely affected if any of the above requirements are not met. For metal buildings, fasten 2" x 2" x 3/16" (or larger) angle iron frames to the building purlins. Retain 5-1/2" between frames (Figure 1). Shaft Support Bracket with Bearing (Not Provided) Door Sprocket 5-1/2" (13.97 cm) All MJ, MH, and HMJ series operators have dual output shafts and may be mounted on either the right (standard) or left side of door, and in either a vertical (standard) or horizontal mounting position. If you need to move the drive sprocket, loosen BOTH set screws, remove the sprocket and key, and place on the opposite side of the drive shaft. Be sure to tighten BOTH set screws securely Hand Chain Handing For MH and HMJ models with manual hoist hand chain systems, the handing of the operator must be determined at the time of order. The handing is indicated by last letter of the model name (R or L). The hand chain wheel can not be switched on site. If your installation causes the hand chain to hang in the door opening, hook the chain off to the side near the top of the door jamb. (2) Set Screws Output Shaft Key Drive Sprocket 3