Product Overview
The Allen-Bradley 1794-TB3G Flex I/O Terminal Base Unit is a key component in the Flex I/O 1794 series, designed to host I/O modules and provide secure wiring termination. This terminal base unit mounts on a panel or DIN rail, offering a robust foundation for field wiring connections in demanding industrial environments.
With 36 maximum input/output terminal points, two common terminals, and two positive voltage terminals, the 1794-TB3G supports a wide range of I/O configurations. It delivers a FLEXBUS current of 640 mA at 5V DC and handles a maximum I/O terminal current of 2A, ensuring reliable power distribution to connected modules.
Technical Specifications
| Parameter |
Value |
| Manufacturer |
Rockwell Automation |
| Brand |
Allen-Bradley |
| Part Number |
1794-TB3G |
| Product Type |
Flex I/O Terminal Base Unit |
| Terminal Screw Torque |
0.56–0.79 Nm |
| Supply Voltage Range |
Max 31.2V DC/AC, 50/60Hz, 10A |
| Isolation Voltage |
50V Continuous max. |
| Voltage Rating |
24V DC/AC |
| Wire Size |
0.21–1.3 mm² |
| Dimensions |
94 x 94 x 69 mm |
| UPC |
10612598180230 |
Key Features & Benefits
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High I/O Density: 36 terminal points accommodate multiple signals, reducing space requirements.
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Flexible Mounting: Panel or DIN rail installation simplifies integration into existing control panels.
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Wide Temperature Range: Operates from -20°C to 70°C without derating, suitable for harsh environments.
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Robust Isolation: 50V continuous isolation voltage protects against electrical interference.
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Secure Connections: Grounded screw clamp ensures reliable wire termination.
Industry Applications
The Allen-Bradley 1794-TB3G is widely used in manufacturing lines, process control systems, and material handling equipment. For example, in a packaging line, the 1794-TB3G provides a stable wiring base for discrete I/O modules that monitor sensors and control actuators, ensuring smooth operation. In a water treatment plant, it connects analog input modules that measure flow and pressure, enabling precise process control.
Its 24V DC/AC rating and high current capacity make it suitable for both DC and AC control circuits, offering flexibility across different automation setups.
Installation & Setup
Mount the 1794-TB3G on a standard DIN rail or panel using the integrated mounting holes. Ensure the terminal base is firmly secured before inserting any I/O module. Wire field devices to the screw clamp terminals, tightening to the specified torque of 0.56–0.79 Nm to guarantee a solid electrical connection.
Use copper wire with a cross-section of 0.21–1.3 mm² (24–16 AWG) rated at 75°C. Keep wiring neat and away from high-voltage sources to minimize noise. After wiring, verify that all connections are tight and that the module is correctly seated on the bus.
Maintenance & Reliability
Inspect the 1794-TB3G periodically for loose connections, especially after vibration or thermal cycling. Check terminal screws for proper torque and re-tighten if necessary. Keep the unit clean and dry, as it is rated for 5–95% non-condensing humidity. Operating within the -20°C to 70°C range ensures long-term reliability.
Because the 1794-TB3G is a passive component, it has no moving parts, reducing wear. Regular visual inspections and preventive maintenance will extend its service life and prevent unexpected downtime.
Compatibility & Integration
The 1794-TB3G is designed for the Allen-Bradley Flex I/O 1794 series. It connects I/O modules to the FLEXBUS, allowing communication with Allen-Bradley controllers such as ControlLogix, CompactLogix, and PLC-5 systems. The terminal base supports a wide range of Flex I/O modules, including digital, analog, and specialty modules, making it a versatile choice for system expansion.
Selection Guide
Before purchasing, verify that your I/O modules are compatible with the 1794-TB3G terminal base. Check the number of I/O points and the voltage requirements of your application. Consider the environmental conditions — the 1794-TB3G operates in temperatures from -20°C to 70°C and humidity up to 95% non-condensing, making it suitable for most industrial settings.
When you need a reliable terminal base for your Flex I/O system, choose the Allen-Bradley 1794-TB3G from PLC Source PRO to ensure authentic parts and fast delivery.