Allen-Bradley 1794-TB3G Flex I/O Terminal Base Unit Overview

Product Introduction

When designing or maintaining a distributed I/O system, the Allen-Bradley 1794-TB3G provides a reliable foundation for hosting Flex I/O 1794 modules. This terminal base unit serves as the physical and electrical interface between field wiring and the I/O bus, simplifying installation and reducing wiring errors. As part of the Rockwell Automation Flex I/O family, the 1794-TB3G is engineered for demanding industrial environments where uptime and ease of maintenance are critical.

Technical Specifications

The 1794-TB3G terminal base unit offers a robust set of specifications tailored for flexible automation setups:

Supply Voltage Range: Maximum 31.2V DC/AC, 50/60 Hz, 10A

Voltage Rating: 24V DC/AC

Isolation Voltage: 50V continuous maximum

Terminal Screw Torque: 0.56–0.79 Nm

Wire Size: 0.21–1.3 mm² (24–16 AWG) stranded copper wire rated at 75 °C

Dimensions: 94 x 94 x 69 mm

Operating Temperature: –20 to 70 °C

Storage Temperature: –40 to 85 °C

Relative Humidity: 5–95% non-condensing

Shock Rating: 30G operational

Vibration Rating: 5G at 10–500 Hz

These parameters ensure the 1794-TB3G can withstand harsh industrial conditions while maintaining stable I/O connections.

Industry Applications

The 1794-TB3G is ideal for manufacturing lines, process control skids, and material handling systems where space is limited. For example, in a packaging line, this terminal base unit can host analog and digital Flex I/O modules to monitor sensors and control actuators, all while simplifying wiring through its 36 terminal points. Its wide operating temperature range makes it suitable for both refrigerated environments and hot factory floors.

Installation & Setup Guidance

Mount the 1794-TB3G on a standard DIN rail or panel using the integrated mounting slots. Use copper wire sized between 0.21 and 1.3 mm² with 1.2 mm insulation, and tighten terminal screws to 0.56–0.79 Nm. Ensure the supply voltage does not exceed 31.2V DC/AC and that the system is properly grounded using the 10 chassis ground terminals. The unit supports up to 36 I/O points with 2 common and 2 positive voltage terminals, simplifying field wiring organization.

Maintenance & Reliability

Regularly inspect the 1794-TB3G for loose connections or signs of corrosion, especially in high-humidity environments. The unit's non-condensing humidity tolerance of 5–95% and operational shock rating of 30G help maintain reliability in vibrating machinery. Follow manufacturer guidelines for periodic testing to ensure long-term performance.

Selection Guide & Purchasing Advice

Before ordering, verify that your Flex I/O modules are compatible with the 1794-TB3G terminal base. This unit supports a FLEXBUS current of 640 mA at 5V DC and a maximum I/O terminal current of 2A. For complete technical specifications and current availability, contact BluePLC Industrial. Our team can help you confirm lifecycle status and recommend the best configuration for your application.