Description
Note: Many products are not yet listed. Please contact us for more product information. Our supply channels are constantly expanding, and we currently have 20 stable shared supply channels. Please confirm the model, product, price, and all other necessary information with customer service before placing an order. We offer new, refurbished, and used products, and prices are adjusted according to the year of the item you require.
Product Introduction
When your Rockwell ControlLogix PLC system needs a highly reliable on-site signal wiring accessory to realize stable connection between I/O modules and field sensors/actuators, and support quick hot-swap maintenance without rewiring, this terminal block acts as the core signal connection bridge.
It is a flagship 20-position NEMA standard screw clamp removable terminal block from Allen-Bradley ControlLogix series, specially designed for heavy industrial automation environments. It supports 20 independent signal wiring positions, and the reinforced screw clamp structure can effectively prevent wiring looseness caused by long-term vibration in industrial sites. It can be seamlessly matched with most 1756 series analog and digital I/O modules such as 1756-IF16, 1756-OF8, etc. The quick-release design allows users to replace the I/O module without removing the on-site signal wires, greatly reducing PLC system maintenance downtime. Its industrial-grade design fully adapts to harsh industrial site environments, making it a core replacement part for ControlLogix PLC system maintenance and retrofit projects.
1756-TBNH/A
1756-TBNH/A
1756-TBNH/A
1756-TBNH/A
Key Technical Specifications
| Parameter | Value |
|---|---|
| Part Number | 1756-TBNH/A |
| Product Type | 20-Position NEMA Screw Clamp Terminal Block |
| Manufacturer | Allen-Bradley (Rockwell Automation) |
| Country of Origin | Mexico |
| Total Wiring Positions | 20 positions |
| Connection Method | Screw clamp type |
| Standard Compliance | NEMA industrial electrical connection standard |
| Compatible I/O Modules | 1756 series analog/digital I/O modules (1756-IF16, 1756-OF8, etc.) |
| Installation Method | Directly snap onto the rear of ControlLogix I/O modules |
| Net Weight | ~0.12 kg |
| Warranty | 12 months from delivery |
Field Application & Technical Pitfalls
Critical Industrial Scenarios
- **Large Petrochemical Plant Control System On-Site Signal Wiring: Acts as the core wiring connection unit for ControlLogix PLC I/O modules in petrochemical production plants, realizing stable connection between on-site sensors/actuators and PLC system, ensuring zero loose wiring failure of process control signals.
- **Automated Manufacturing Production Line PLC I/O Wiring System: Delivers reliable heavy-duty anti-vibration wiring performance for automated production line PLC systems, adapting to long-term high-vibration industrial environments, meeting the long-term stable operation requirements of automated production equipment.
- **Thermal Power Plant DCS System I/O Signal Connection: Adapts to high-temperature and high-dust power plant workshop environments, providing stable signal wiring support for the I/O modules of large power plant distributed control systems.
Non-Negotiable Technical Pitfalls
- ⚠️ Bold Warning 1: Never arbitrarily use non-matching non-1756 series standard terminal blocks for connection. The third signal channel will experience poor contact that causes the signal to be interrupted.
- ⚠️ Bold Warning 2: Skipping the pre-commissioning full wiring point torque check will leave you with hidden loose wiring risks. This terminal block must confirm all 20 wiring screws are tightened to the factory specified torque value before putting into operation.
- ⚠️ Bold Warning 3: Do not arbitrarily connect multiple signal wires to a single wiring position. The third wiring point will experience overcrowding that causes the wire to fall off during long-term operation.
A large petrochemical plant maintenance team once swapped an Allen-Bradley 1756-TBNH/A terminal block and skipped the full torque check. The hidden single wiring screw was not tightened, causing the analog signal to fluctuate abnormally, resulting in a 1-hour partial shutdown of the production unit.
Quality Control (QC) SOP & Transparency
- Inbound Verification: Cross-check the OEM serial number against Rockwell Automation’s official ControlLogix part registry, confirm the part number 1756-TBNH/A matches the factory label, and inspect no damage or deformation on all screw clamps and module buckles.
- Live Rig Testing: Snap the terminal block onto a standard 1756 I/O module, simulate on-site wiring operation, and confirm full 100 times plugging and unplugging test without loose structure.
- Parameter Testing: Verify all 20 wiring positions’ screw clamping force meets factory specifications, confirm the module buckle connection is firm and reliable, and validate all mechanical structures meet NEMA industrial standards.
- Final QA & Packaging: Seal the tested terminal block in a static-shielding anti-static bag, attach a unique QC passed serial label, and nest it in foam padding inside a rigid industrial shipping carton.
Frequently Asked Questions (FAQ)
- Can I hot-swap the I/O module with this terminal block while the PLC system is running? Yes, it supports ControlLogix I/O module hot-swap function, you only need to unlock the buckle to remove the I/O module without touching the on-site signal wires, which greatly reduces maintenance downtime.
- What exact modules is this terminal block compatible with? It works natively with most 1756 series analog and digital I/O modules such as 1756-IF16, 1756-OF8, etc., and cannot be directly used in non-ControlLogix PLC I/O modules without custom adaptation.
- How long is the standard warranty for this new surplus unit? 12 months from delivery. It covers all manufacturing defects, but does not extend to units damaged by improper wiring, over-tightening the screw to cause thread slipping, or man-made damage in the field.
- How do I tell a genuine OEM unit apart from a refurbished clone? Genuine Allen-Bradley 1756-TBNH/A terminal blocks have a laser-etched part number on the housing, not a printed sticker. Clone units almost always fail the full 20-point screw clamping force durability test.
- What is the typical lead time for shipment? In-stock units ship within 48 hours. If you require official Rockwell Automation factory wiring performance test documentation, add 2 extra business days to the turnaround window.
- Can this terminal block replace the older 1756-TBNH non-A version legacy unit? Yes, they are 100% mechanically and electrically compatible, and can be directly replaced without any modification.
