Allen-Bradley 1794-TB3 Flex I/O Terminal Base Unit

Product Overview

The Allen-Bradley 1794-TB3 is a Flex I/O terminal base unit. It offers three strips of screw clamp terminals. The top strip has 16 I/O terminals. The middle strip has 18 common terminals. The bottom strip has 18 supply terminals. This base supports daisy-chaining to other bases. It handles up to 120 VAC and 10 Amperes. The backplane draws 640 mA at 5 VDC.

Application Scenarios

This terminal base hosts digital I/O modules like 1794-IA8, 1794-OA16, and 1794-IB8. It provides termination for field device wiring and power supplies. Use it in automation systems, packaging lines, and material handling. The base integrates with any Flex I/O adapter module.

Technical Specifications

• Manufacturer: Rockwell Automation / Allen-Bradley
• Part number: 1794-TB3
• Product type: Flex I/O Terminal Base Unit
• Supply voltage: 125V DC/AC max, 120 VAC nominal
• Current rating: 10 Amperes max
• Backplane current: 640 mA @ 5VDC
• Terminal strips: Three strips (16 I/O, 18 common, 18 supply)
• Total terminals: 52
• Wire size: 0.34-3.3 mm² (22-12 AWG)
• Screw torque: 0.56-0.79 Nm
• Isolation voltage: 125V continuous
• Dimensions: 94 x 94 x 69 mm
• Mounting: DIN Rail
• Compatible with: 1794-IA8, 1794-IA16, 1794-OA8, 1794-OA16, 1794-IB8, 1794-OB16, and many others.

Installation & Maintenance Guide

Mount the base on a DIN rail. Hook the top edge over the rail. Push down until it locks. Ensure the FlexBus connector engages with the adjacent adapter. Tighten terminals with a torque screwdriver set to 0.56-0.79 Nm. For daisy-chaining, connect C-34 (+) and B-16 (-) as supply in. Connect C-51 (+) and B-33 (-) as supply out. No periodic maintenance needed. Keep the base clean and free of debris.

Packing List

• 1 x Allen-Bradley 1794-TB3 Terminal Base Unit
• Installation instructions