Overview
The NB-4120-2-DC, Single and Bi-Parting Sliding Door Operator, is designed and tested for
lead shielding doors weighing up to 35,000 lbs (single door)/17,500 lbs (each bi-parting door),
operating at linear speeds of 6.0 in/sec maximum (single door)/12.0 in/sec maximum (bi-parting
doors), or a maximum horizontal operating force of 700 lbs (single door) or 350 lbs (each bi-
parting door). The drive train features a 2” wide (H) pitch, polyurethane, steel reinforced timing
belt, coupled to a ¾ hp, 90VDC, helical-bevel (high torque) gear motor. Since the drivetrain
features a ¾ 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.
This power open/power close electro-mechanical operator with its state of the art
components, make it the strongest, most reliable and easiest to install in the industry today.
Refer to the Wiring Legend for Terminal Strip Hookup for all open, close, stop and
External Safety Device inputs, which are all Class (2) 24VDC normally open momentary
contact (except the stop input, terminal #10, which is a normally closed input). Power
supply hookups for both Class (2) 24VDC, and 230VAC, 3 phase are also indicated. The
PLC then processes all this information, in addition to many other features for proper control
of these heavy lead or concrete doors. This door operator is patented under US Patent No.
6,177,771 B1.
The NB4120-DC Commercial/Industrial Sliding Door is compliant with UL 325 under
Section External Entrapment Protection featuring Fail Safe Monitoring, providing all
External Safety Devises are wired and installed per this manual.
We are Authorized to Mark the NB-4120-DC with the ETL and CE markings from Intertek
Testing Services to assure compliance with UL 325, FCC Part 15 (Emissions) and the
following International Standards: EN 60335-1 and -2 (Safety), EN 61000-6-2 (Immunity)
and EN 61000-6-4 (Emissions). The “listing” reports specifically refer to the heavy
commercial/industrial doors associated with linear accelerator rooms.
Logic Control:
This Operator offers the latest technology in PLC (Programmable Logic Control). The
following (3) modules snap to a DIN rail base: CPU (Central Processing Unit) - processes
and stores data in its internal register such as door position presets, inputs from pushbutton
