Flex I/O Terminal Base Unit Allen-Bradley 1794-TB3 - 640 mA, 120 VAC

Product Overview

The 1794-TB3 is a Flex I/O terminal base unit from Allen-Bradley. This component provides termination points for field devices and power supplies. It hosts compatible Flex I/O modules like the 1794-OA16. The base has three terminal strips with 52 screw terminals total. It supports daisy-chaining for easy expansion. The unit draws 640 mA from the backplane at 5 VDC. Its voltage rating is 120 VAC with a maximum current of 10 Amperes. This terminal base is ideal for building distributed I/O systems in industrial automation.

Application Scenarios

Use the 1794-TB3 with Allen-Bradley Flex I/O adapters and modules. It works well in manufacturing plants, process control, and machine automation. The terminal base connects sensors, actuators, and other field devices. It also distributes power to multiple I/O modules. Common applications include conveyor control, packaging machines, and material handling systems. Its rugged design suits harsh industrial environments.

Technical Specifications

• Manufacturer: Rockwell Automation
• Brand: Allen-Bradley
• Type: Flex I/O Terminal Base Unit
• Terminal Strips: 3 strips
• Number of Terminals: 52
• Connection Type: Screw clamp
• Voltage Rating: 120 VAC, max 132 VAC
• Current Capacity: 10 Amperes
• Backplane Current Draw: 640 mA at 5 VDC
• Isolation Voltage: 125 V Continuous
• Wire Size: 0.34-3.3 mm² (22-12 AWG)
• Dimensions: 94 x 94 x 69 mm
• Mounting: DIN Rail
• Daisy-chaining: Supported
• Compatible Modules: Includes 1794-IA8, 1794-OA16, and many others

Installation & Maintenance Guide

Install the 1794-TB3 on a standard DIN rail. First, angle the base and hook it over the top of the rail. Slide it tight against the adjacent adapter. Push the base until it locks into place. Ensure the FlexBus connector engages correctly. Use the provided screw terminals for wiring. Tighten screws to 0.56-0.79 Nm torque. For daisy-chaining, connect terminals C-34 (+) and B-16 (-) for supply in. Use C-51 (+) and B-33 (-) for supply out. The top strip (16 terminals) handles I/O signals. The middle strip (18 terminals) connects common. The bottom strip (18 terminals) connects voltage supply. Regular inspection of terminal tightness ensures reliable connections. No special maintenance is required beyond periodic checks.

Packing List

• 1x 1794-TB3 Flex I/O Terminal Base Unit
• Installation instructions (if included)