Allen-Bradley 1794-TB3G FLEX I/O Terminal Base | 3-Channel, Fused, IP20, DIN Rail Specs

Allen-Bradley 1794-TB3G FLEX I/O Terminal Base | 3-Channel, Fused, IP20, DIN Rail Specs

Allen-Bradley 1794-TB3G FLEX I/O terminal base unit specifications. 3-channel fused terminal base, screw terminals, DIN rail mount, IP20. For industrial I/O wiring with fuse protection.

Product Overview

The Allen-Bradley 1794-TB3G​ is a 3-channel fused terminal base unit​ from the FLEX I/O series, designed for industrial I/O wiring applications requiring circuit protection. This terminal base provides connection points for 3 channels​ of I/O signals with individual fuse protection for each channel, screw terminal connections, and DIN rail mounting. The "1794" designation indicates the FLEX I/O series, "TB3G" specifies the 3-channel fused terminal base configuration. This unit serves as a protected interface between FLEX I/O modules and field wiring, providing secure, reliable connections with built-in fuse protection for I/O signals in distributed control systems.

Technical Specifications

Note: Specifications are based on Allen-Bradley 1794 series technical documentation. The "1794-TB3G" model specifically indicates 3-channel fused terminal base configuration. Actual specifications may vary slightly depending on production batch.

Model Number Decoding (1794-TB3G)

• 1794:​ Series designation (FLEX I/O series)

• TB3G:​ Product type (TB = Terminal Base, 3 = 3 channels, G = fused version)

Note:​ The "TB" prefix indicates Terminal Base functionality. The "3" specifies 3 channels of I/O connection points. The "G" suffix indicates the fused version with individual fuse protection for each channel. This is the protected version of the standard 1794-TB3 terminal base.

Key Features

• 3-Channel Design:​ Connection points for 3 I/O signals

• Individual Fuse Protection:​ Separate fuse for each channel (2A fast-acting)

• Fuse Status Indicators:​ LED indicators show fuse status (blown/OK)

• Screw Terminals:​ Secure wire connections with screw terminals

• DIN Rail Mounting:​ Easy installation on standard 35mm DIN rail

• Module Locking:​ Positive mechanical latch for secure module attachment

• Clear Identification:​ Numbered terminals and fuse positions

• Durable Construction:​ Polyamide housing for industrial environments

• Wide Temperature Range:​ Suitable for industrial applications

• Easy Installation:​ Tool-less module attachment and removal

• Ground Connection:​ Dedicated ground terminal for proper grounding

• Compact Design:​ Space-efficient footprint for high-density installations

Terminal and Fuse Configuration

Typical Applications

• Protected I/O Wiring:​ Fused connection points for digital input/output signals

• Analog I/O Protection:​ Fuse protection for analog signal wiring

• Sensor Connection:​ Protected termination for sensor signals

• Actuator Control:​ Fused wiring interface for control outputs

• Machine Control:​ Protected I/O wiring for machine automation

• Process Control:​ Fused field wiring for process instrumentation

• High-Value Equipment:​ Protection for connected field devices

• Safety Circuits:​ Additional protection for safety-related circuits

• Test Equipment:​ Protected signal connection for test systems

• Critical Processes:​ Protection for critical control loops

Important Technical Notes

1. Fuse Requirements:​ Requires 3 × 5×20 mm, 2A fast-acting fuses (user-supplied). Do not exceed 2A rating. Use fuses with appropriate interrupting capacity.

2. Module Compatibility:​ Designed for use with 1794 series I/O modules. Ensure module channel count matches terminal base channel count.

3. Wiring Guidelines:​ Use proper wire size (12-24 AWG). Strip wire to appropriate length (7-8 mm). Follow torque specifications for terminal screws.

4. Grounding:​ Always connect ground terminal to proper earth ground for safety and noise immunity.

5. Fuse Replacement:​ Replace fuses only with power disconnected. Use identical type and rating (2A fast-acting).

6. LED Indicators:​ Green LED indicates fuse is intact. No light indicates blown fuse. LED requires power to module to illuminate.

7. Mounting:​ Install on 35mm DIN rail with proper orientation. Ensure adequate clearance for wiring and module installation.

8. Environmental Conditions:​ Install in appropriate enclosure for additional protection. IP20 provides limited protection against dust and moisture.

9. Maintenance:​ Periodically check fuse status indicators and terminal tightness. Replace blown fuses promptly and investigate cause.

Note: For complete installation guidelines, wiring diagrams, application notes, and detailed technical data, consult the official Allen-Bradley 1794 Series Technical Manual. Always verify the exact model number configuration with the manufacturer, as notation variations may occur.