The Model J is an industrial-duty jackshaft door opener, as manufactured by The Chamberlain Group, Inc. and is for use on vertical or high lift sectional doors, rolling doors and grilles. It is rated for 25 cycles per hour during peak periods. Up to 80-90 cycles/day.


  • Drive system : chain hoist
  • Voltage/phase :
    115/230 V 1 phase
    208/230/460 V 3 phase
    575 V 3 phase
  • Horse power : available in  ½, ¾ and 1 h.p.
  • Minimum sideroom required: 20″
  • Continuous-duty high-starting hoist operator with instant reverse.
  • Removable hinged electrical box cover.
  • 24V NEC Class 2 Circuit with 40 VA transformer
  • Capacitor start on single-phase.
  • Motor is removable without affecting limit switch settings.
  • All operators are factory preset to C2 wiring, providing momentary contact to open and stop, with constant contact to close. Monitored entrapment protection, using approved photo sensors CPS-U are standard. All other wiring types, B2, T, TS and FSTS, can be selected with the selection of a switch. LiftMaster CPS-UN4 and CPS-RPEN4 photo sensors or a monitored 4-wire sensing edge (via a CPS-EI Edge Interface Card) are optional. Logic 4.0 door openers can only accept UL-approved LiftMaster CPS-U, CPS-UN4, CPS-RPEN4 or CPS-EI monitored entrapment protection devices.
  • Universal mount frame design.
  • First-stage heavy-duty 5L V-Belt; second and third stages #48 chain; #50 drive chain.
  • Industrial ball bearings on 1″ output shaft; heavy-duty oil-filled iron bearings on reduction shafts.
  • Adjustable friction clutch helps protect against major damage to door and operator should the door meet an obstruction.
  • Provides emergency manual operation using an electrically interlocked floor level disconnect and chain hoist mechanism.
  • Motor overload protection.
  • NEMA 1 type electrical box, heavy-duty 11-gauge steel frame with durable powdercoat finish, all reduction sprockets drilled and pinned to shafts.
  • 1.5 second delay-on-reverse circuit to prevent premature door and opener wear.
  • The Timer-to-Close automatically closes the door – programmable in 1-second or 15-second increments.
  • The mid-stop stops the door at programmable mid-stop during open travel.
  • The Maximum Run Timer signals the door to reverse or stop if closing time exceeds maximum by more than 10 seconds.
  • Maintenance alert system (5 000 to 10 000 cycles).
  • UL and CSA listed.
  • 2-year warranty.

    Your security, our priority!

    CPS® Commercial Protector System®

    The presence of primary entrapment protection is standard CPS-U for all modes. Primary entrapment protection devices are monitored continuously to insure safe operation of the door and limit door opener functionality should an obstruction be detected or in the event of device failure. Optional LiftMaster Monitored Entrapment Protection devices,  CPS-UN4, CPS-RPEN4 and CPS-EI, are designed to work in conjunction with LiftMaster commercial door openers to provide enhanced door safety and a broad range of modes and features to end users. Either monitored photo-sensor or monitored 4-wire sensing edge (in conjunction with the CPS-EI Edge Interface) protection may be selected, but one must be detected by the LiftMaster Logic 4.0 or Medium-Duty Logic circuit board in order to unlock full functionality.

    PosiLoc® Mechanical Brake System

    Self-locking mechanical reduction system functions as a holding brake.



    Garage doors and garage door openers can be dangerous if not installed and verifed by a professionnal and not used properly . Chidlren must be supervised by an adult when they are inside or in proximity of the garage.

    Included with the LiftMaster J door opener

    • LiftMaster J door opener
    • Chain Tensioner
    • 3-Button Control Station
    • Receiver included (transmitter in option)
    • Hardware bag for installation (includes all necessary hardware for installation)