LiftMaster Model MJ
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MJ Medium-Duty Series Logic Jackshaft Operator
The MJ is a medium-duty logic jackshift operator featuring a compact design for use on industrial sectional doors with high or vertical lift and on small rolling doors and grilles.
- Programmable C2 or B2 wiring options (B2 requires installed Monitor Entrapment Protection Device) to meet business requirements for commercial door operator control.
- Powerful high-starting torque ½ HP, single-phase motor with internal automatic reset thermal overload is removable without affecting limit switch settings.
- Floor-level disconnect provides emergency manual operation.
- Adjustable friction clutch helps protect against major damage to door and operator should the door meet an obstruction.
- Drive Reduction, first stage heavy-duty 4L V-belt; second stage and third stages #48 chain.
- Integrated 90 second maximum run timer.
- Heavy-duty solenoid actuated brake standard.
- Heavy-duty oil-filled bushings.
- NEMA 1 type electrical box, heavy-duty 11-gauge steel frame with durable powder-coated finish, all reduction sprockets drilled and pinned to shafts.
- Easily field converted for right or left mounting.
- Operator/Motor Control: Solid-State Medium-Duty circuit board.
- 3-button station for OPEN/CLOSE/STOP functions is standard for all door operators.
- Warranty: 2 Years.
- Built-in-3-channel, 315 MHz radio receiver accepts up to (20) LiftMaster Security+ or unlimited DIP switch remote controls. 3-button remote controls can be programmed for OPEN/CLOSE/STOP operation.
- Integrated Timer-to-Close (TTC) for timed automatic door closure after the door reaches the full open position for added security and peace of mind. Programmable from 5-60 seconds in 5-second increments.
- LiftMaster Commercial Door Operators comply with UL 325 standards for Monitored Entrapment Protection.
- Control circuit: 24V NEC Class 2 control circuit
NOTE:
- The MJ Operator is not recommended for use in large or high rolling doors without chain hoist modification (see Model MH).
- On steel-insulated doors, a 24 ga. back panel is assumed.
RECOMMENDED CAPACITIES
Maximum recommended duty cycle: 12 cycles per hour.