Liftmaster MODEL LGJ Light-Duty Gear-Reduced Jackshaft Garage Door Opener

Light-Duty Gear-Reduced Jackshaft Operator for Rolling Grilles and Shutters

Applications:

The Model LGJ door operator is designed for use on rolling grilles and shutters, and small rolling doors. Maximum recommended duty cycle: 7 cycles per hour.

Standard Features:

Internal door lock sensing circuit

3-button control station

Solid state control and motor drive

High starting torque motor with overload protection

24VAC control circuit

Long-life dry type capacitor

Heavy-duty wormgear-in-oil-bath speed reducer

Prewired to accept sensing devices

Fully adjustable linear driven limit switch mechanism

Motor removable without affecting limit switches

NEMA 1 type electrical enclosure

Floor level disconnect for emergency manual operation

41B32 door sprocket and #41 drive chain included

Baked-on high-durability black powdercoat finish

Approximate shipping weight - 35 lbs.

2-year warranty

The Door Lock Sensing Circuit: The Model LGJ includes a speed sensor in the electrical enclosure and a sensing circuit which sends a signal to stop the motor if the door jams, such as would be caused by failure to release the lockbar of a rolling grille before starting the operator. In addition to stopping the motor, if the door or grille is in fully closed position, it will drive the motor in the opposite direction for approximately 1 inch of door travel. This releases the pressure on the lockbar thus allowing the lock to be easily opened.

This modification also contains logic that can be used to sense obstruction to door movement in mid-travel. The circuit is programmed to stop a door that is obstructed while opening and reverse a door that is obstructed closing. Warning: THIS FEATURE SHOULD NOT BE USED IN LIEU OF A BOTTOM BAR SENSING EDGE OR OTHER ENTRAPMENT PROTECTION DEVICE. THE CIRCUIT FUNCTIONS ONLY WHEN THE OPERATOR IS STALLED; THEREFORE, IN THE CLOSING MODE, A ROLLING DOOR OR GRILLE WILL "BUNCH UP" BEFORE THE CIRCUIT FUNCTIONS.