The Model MH Medium Duty Hoist Operator is designed for use on small rolling doors, grilles and industrial sectional doors with high or vertical lift. 115 volt 1 Ɵ. With Open/Close/Stop functions, the three push-button control station is standard for all operators. Controls with one, two and three buttons are available. Maintenance Alert System provides notifications when routine maintenance is required on your Commercial Door Operator. With a powder-coated finish, the NEMA Type 1 electrical box construction is durable enough for most applications. Heavy-duty, oil-filled bushings. Mounts on the left or right side of the door. No rails to hang—the Door Operator simply mounts on the wall and attaches to the door shaft through chain and sprocket. Door Operator electromechanical limit system enables ease of installation and adjustment to ensure accuracy, even after a power failure. Programmable in one-second or 15-second increments, Time-to-Close automatically closes the door. Ensure peace of mind with a LiftMaster two-year warranty It features an adjustable friction clutch, a standard solenoid brake, a high-starting torque motor, a compact design and an emergency chain hoist with an electric interlock. Electrical interlock for emergency manual door operation with Floor level chain hoist. 3-channel radio receiver on board. Linear-driven limit mechanism is fully adjustable 3-button control station Meets all UL 325 requirements. Patented Security+ radio technology accepts 20 remote controls and unlimited DIP switch remote control. Adjustable Friction Clutch helps protect against damage to the door and Door Operator should the door meet an obstruction. Signals door to reverse or stop if closing time exceeds maximum door travel to prevent damage to door and Door Operator. Provides easy emergency manual operation using an easily accessible disconnect.