1794-TB3T | Allen-Bradley | FLEX I/O Temperature Grounded Terminal Base Unit

Product Overview

The Allen-Bradley 1794-TB3T functions as the essential mounting and wiring interface for the FLEX I/O 1794 system. This terminal base provides the physical connection points for I/O modules, specifically catering to temperature-sensing applications like RTDs and thermocouples that require grounded terminations or 3-wire configurations. We supply this unit as 100% Brand New original factory stock. It enables high-density distributed I/O by allowing modules to snap directly onto the base, eliminating the need for separate row-mounted terminal blocks and extensive cabinet internal wiring.

Technical Specifications

Engineering Advantages

• Optimized Temperature Wiring: The 1794-TB3T features additional cold-junction compensation (CJC) capabilities and grounded terminals. These connections facilitate the precise wiring required for 3-wire RTDs and thermocouples, ensuring the system maintains thermal accuracy across large-scale distributed architectures.

• Modular "Change-on-the-Fly": This terminal base supports the removal and insertion of I/O modules under power (RIUP). Maintenance teams replace faulty modules without disconnecting field wiring or shutting down the entire I/O rack, significantly reducing process downtime.

• High-Current Power Distribution: The unit handles up to 10A of current. This high capacity allows the base to distribute power to multiple daisy-chained modules through the internal FlexBus, reducing the number of external power drops required in the cabinet.

• Versatile Voltage Compatibility: Designed to manage a wide spectrum of signals from 24V DC up to 120V AC, the 1756-TB3T provides a standardized platform for both digital and analog Flex I/O modules. The 125V continuous isolation protects the backplane from field-side voltage spikes.

• Cabinet Space Efficiency: The compact design integrates terminal blocks directly into the module mounting structure. This hardware consolidation saves up to 30% of DIN rail space compared to traditional PLC rack and terminal strip configurations, making it ideal for localized junction boxes.

FAQs

• Can I use the 1794-TB3T with standard digital I/O modules?

  Yes. While specifically designed for temperature modules (like the 1794-IRT8), the 1794-TB3T provides standard 3-wire termination that works with most 1794 series digital or analog modules.

• Does the unit require a specific type of wire?

  The cage-clamp terminals accept solid or stranded copper wire ranging from 22 AWG to 12 AWG ($0.34–3.3mm^2$). Ensure you adhere to the specified torque rating (max 0.79 Nm) to prevent terminal damage and ensure gas-tight connections.

• Is the 1794-TB3T compatible with the 1794-TB3?

  They share the same footprint, but the "T" version (1794-TB3T) includes extra terminals for temperature applications and grounding. Always check your module's manual to confirm if it requires the specific "T" grounded base.

• How do I verify this is an authentic, brand-new unit?

  We guarantee every 1794-TB3T is 100% Brand New in original factory packaging. Each unit features the genuine Rockwell Automation holographic label or factory stamp, ensuring the plastics and terminal contacts are in pristine, un-cycled condition.