Allen-Bradley 1794-TB3G Flex I/O Terminal Base Unit for Reliable Industrial Wiring

What Is the 1794-TB3G Terminal Base Unit?

When your control system demands reliable I/O wiring connections, the Allen-Bradley 1794-TB3G Flex I/O terminal base unit delivers a robust solution. This terminal base is part of the Flex I/O 1794 series and serves as the physical interface between field wiring and I/O modules. It mounts on a panel or DIN rail and provides up to 36 input/output terminal points with 2 common terminals and 2 positive voltage terminals. The 1794-TB3G also includes 10 chassis ground terminals for secure grounding.

Technical Specifications

The 1794-TB3G operates with a supply voltage range of max. 31.2V DC/AC at 50/60 Hz and 10A. It delivers a voltage rating of 24V DC/AC and provides isolation voltage of 50V continuous max. The terminal screw torque is set at 0.56-0.79 Nm (5-7 lb-in). Wire size ranges from 0.21 to 1.3 mm² (24-16 AWG) using stranded copper wire rated at 75°C (167°F) with 1.2 mm (3/64 in) insulation. The unit measures 94x94x69 mm and carries the T4A and IEC TA temperature codes.

Industry Applications

In manufacturing environments where temperature extremes and vibration are common, the 1794-TB3G provides a stable wiring platform. It functions without de-rating at -20 to 70°C (-40 to 158°F) and withstands 5-95% non-condensing relative humidity. With an operational shock rating of 30G and vibration of 5G at 10-500 Hz, this terminal base suits applications in automotive assembly lines, material handling systems, and process control skids. The 1794-TB3G also delivers a FLEXBUS current of 640 mA at 5V DC with a 2A maximum I/O terminal current, ensuring reliable communication between modules.

Installation & Setup Guidance

Mount the 1794-TB3G on a standard DIN rail or directly to a panel using the provided slots. Use stranded copper wire sized between 0.21 and 1.3 mm² (24-16 AWG) with insulation rated at 75°C (167°F). Tighten terminal screws to 0.56-0.79 Nm (5-7 lb-in) to ensure secure connections. The unit uses grounded screw clamp termination for reliable I/O wiring. Connect the I/O modules to the bus through the terminal base, and verify the voltage/communication terminal rating of 125V DC/AC at 10A (50-60 Hz) to avoid overloading.

Maintenance & Reliability

To maximize the lifespan of the 1794-TB3G, inspect terminal connections periodically for tightness and signs of corrosion. The unit is designed for long-term reliability in harsh conditions, with a storage temperature range of -40 to 85°C (-40 to 185°F). Regular inspection of the chassis ground terminals and wire insulation helps prevent intermittent faults. The 1794-TB3G uses basic insulation type tested for 60 seconds at 2121V DC between field wiring terminals and FLEXBUS, ensuring electrical safety.

Selection Guide & Purchasing Advice

Before ordering the 1794-TB3G, verify that your system requires a Flex I/O terminal base unit with 36 terminal points and 10A current capacity. This unit is compatible with Allen-Bradley Flex I/O 1794 series modules. For complete technical specifications, please contact BluePLC Industrial. Our team can confirm current lifecycle status and availability to ensure the 1794-TB3G meets your application needs.