The NB-4125 Sliding Door Operator is designed and tested for lead shielding doors of any weight providing the maximum operating force of 500 lbs and maximum speed of 16 inches per second have not been exceeded. This is accomplished with a linear drive system comprised of a 2d trolley system.

The NB-4125 is offered in single sliding or in Bi-Parting door applications. The operator mounts at the header of the door and is housed in a 10 linear guide tracking system, which is designed to keep the belt aligned and properly meshed into the pulleys at all times. In addition, it allows the operator to be disconnected for manual operation with a spring-loaded pin that you simply pull down to disengage it from the door. The linear guide tracking system is maintenance free and does not need lubrication. The operator features lightweight aluminum construction throughout, which makes for easier installation and greater corrosion protection.

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-4125 to accommodate inputs from infrared presence sensors and pressure sensitive tape switches that will 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

Unit of Measure

Door Wt 1

N/A 12000 lbs.

Max Operating Force 2

N/A 500 lbs.

Travel (max. in one direction)

N/A Unlimited in.

Rated Linear Speed (max.)

N/A 16 in./sec.


N/A Both

Mounting Style

N/A Front

Drive Train

N/A Timing Belt