Allen‑Bradley 1756‑TBNH 20-Position NEMA Screw RTB Terminal Block

1756-TBNH is Rockwell Allen‑Bradley removable terminal block (RTB) accessory exclusively for 1756 ControlLogix I/O modules, featuring 20-position NEMA standard screw clamp terminals. It serves as the bridge between field sensor/actuator wiring and the front connector of digital/analog I/O cards, achieving separable wiring design to avoid re-cabling during module replacement. The screw locking structure delivers stable wire clamping and anti-vibration performance for continuous production control cabinets.

This pluggable terminal block adopts industrial flame-retardant plastic housing, matched with dedicated wire marking labels for circuit identification. It is a standard spare accessory for all ControlLogix automation lines, widely stocked for maintenance replacement when original terminal blocks suffer aging, screw sliding or wiring damage without altering field cable layout.

Main Specifications

• Brand: Allen‑Bradley (Rockwell Automation); Model: 1756-TBNH; Type: 20-position screw RTB terminal block
• Clamp Standard: NEMA screw clamp, tightening torque 1.36 N·m (12 lb-in)
• Applicable Wire: 22–14 AWG solid/stranded copper wire, wire insulation max 1.2mm thickness
• Power Consumption: 1200mA @5VDC, 2.5mA @24VDC, max power dissipation 6.19W
• Operating Environment: 0℃ ~ +60℃, humidity 5%–95% RH non-condensing, UL & CE certified
• Physical Parameter: Net weight 0.11kg, single-slot front-mounted plug-in structure
• Keying Feature: Support custom mechanical keying to prevent mismatched I/O module installation
• Matching Hardware: 1756 series digital input/output, analog I/O, relay output modules

Core Functions

• Conduct bidirectional signal transmission between on-site field cables and ControlLogix I/O modules, collecting sensor signals and outputting drive control signals.
• Detachable pluggable design: separate terminal block from I/O module directly during maintenance, all field wiring remains intact to drastically cut downtime.
• NEMA screw clamping mechanism firmly locks copper wires, effectively resisting vibration and loose wiring faults in workshop mechanical equipment environments.
• Equipped with numbered marking slots for labeling each signal circuit, simplifying wiring inspection, troubleshooting and later system expansion work.
• Flame-retardant insulating housing with EMC anti-interference performance, suppressing signal noise generated by high-power inverters and motors.
• Universal compatibility with most 1756 standard I/O modules, direct replacement without modification of cabinet wiring or signal allocation logic.

Application Scenarios

• Spare terminal block replacement for ControlLogix automation cabinets in packaging, logistics palletizing and automotive assembly workshops.
• Wiring accessory spare parts for water treatment, petrochemical, metallurgical and pulp & paper process control systems.
• Maintenance backup inventory for mechanical processing, textile printing and dyeing, new energy battery production control panels.
• Matching wiring accessory cooperating with 1756 digital/analog I/O modules and ControlLogix rack power supplies.
• Retrofit replacement components for aged terminal blocks with sliding screws, wire burning and signal disconnection faults.

• Global aftermarket spare stock for discrete manufacturing and process industry maintenance teams maintaining Rockwell ControlLogix hardware.