The NB-4120-2-DC Single Belt, Bi-Parting Sliding Door Operator

is designed and tested for lead shielding doors weighing up to 35,000 lbs (total both doors) operating at linear speeds of 6.0 in/sec maximum (each leaf in opposite directions, totally 12.0 in/sec) or a maximum horizontal operating force of up 700 lbs (total both doors). The drive train features a 2" wide (H) pitch, polyurethane, steel reinforced timing belt, coupled to a 3/4 hp, 90VDC, helical-bevel (high torque) gear motor. Since the drivetrain features a 3/4 hp DC motor, this operator also includes a Battery Backup System and Manual Operation as a redundant backup for power interruption. Applications involving heavier doors at slower speeds/acceleration rates should be referred to the Engineering Department.

The NB-4120-2-DC

is designed to be used in conjunction with an existing linear bearing/rail system capable of supporting heavy doors with a low coefficient of friction or standard beam trolley supports for hanging the door. The open ended style timing belt normally clamps to the side of the door carriage/attachment structure. Once the timing belt has been properly aligned and pre-loaded, in addition to the motor control parameters being correctly set, the NB-4120-2-DC will provide many years of maintenance free service.

The PLC (Programmable Logic Control) is programmed by the manufacturer to accept input signals from an external (4) button station (including open, partial open, close and stop commands). Additional I/O (input/output) are featured with the NB-4120-2-DC to accommodate inputs from infrared presence sensors and pressure sensitive tape switches that will either stop or reverse the door to the open position, when activated in the closing cycle. All input commands to the PLC are class 2, low voltage. There are no limit or proximity switches to adjust or install. Simply adjust the door’s positioning presets as required by interfacing with the PLC via a hand held HMI (purchased separately).

Rating a Sliding Door Operator:

The rating of a sliding door operator in any particular installation cannot be based solely on the weight of the door. Other factors such as linear bearing alignment, coefficient of friction, and acceleration/deceleration rates may have a substantial affect on the total axial force acting on the door operator components. We have factored these variables into the Rated Maximum Operating Forces. This assures the customer they are getting the most dependable product at a reasonable cost over the life expectancy of the operator.

Unit of Measure

Door Wt 1

N/A 35000 lbs.

Max Operating Force 2

N/A 700 lbs.

Travel (max. in one direction)

N/A Unlimited in.

Rated Linear Speed (max.)

N/A 6 in./sec.


N/A Both

Mounting Style

N/A Front

Drive Train

N/A Timing Belt

Minimum Rated Cycles (openings and closings)

N/A 500000