The T8891 acts as a high-integrity interface between the field devices and the Trusted TMR system, ensuring reliable speed output signal distribution. This assembly provides a robust physical connection point, supporting the fault-tolerant architecture required in critical industrial safety applications.

Technical Specifications and Features

Core Electrical Parameters

The T8891 is specifically designed to work in conjunction with the T8442 module, from which it derives its primary power supply. It handles input and output ratings of 3A at 120Vac or 2A at 30Vdc, providing versatile switching capabilities for different industrial environments. The hardware carries the Rockwell Automation part number 3AX185, ensuring full compatibility with the broader ICS Triplex product ecosystem and maintaining system integrity.

Mechanical and Wiring Information

The unit features a screw clamp terminal block (TB) type that supports a wide range of wire sizes from 30 to 12 AWG. Users should apply a precise torque of 0.5 N.m to ensure secure electrical contact and prevent terminal damage during the installation process. Each terminal block allows for one cable termination, which maintains a clean wiring structure and simplifies future maintenance or troubleshooting tasks.

Environmental and Physical Durability

Built for industrial resilience, the T8891 offers high anti-interference capability, which is essential for maintaining accurate speed output signals in high-noise environments. The assembly is designed for standard DIN rail mounting, allowing for quick integration into existing control cabinets without requiring custom mounting brackets. Its temperature range and environmental tolerance meet the strict standards required for Triple Modular Redundant (TMR) safety-instrumented systems globally.

Installation and Maintenance Guide

Standard Installation Steps

1. Verify that the DIN rail is securely grounded before mounting the T8891 unit to the rack.

2. Connect the interface cable from the T8442 module to the appropriate socket on the assembly board.

3. Strip the field wires to the recommended length and insert them into the screw clamp terminals carefully.

4. Apply exactly 0.5 N.m of torque to the screws to finalize the physical wiring of the system.

5. Check the LED indicators on the board to confirm the presence of valid power from the source.

Packing List

• 1 x Allen-Bradley ICS Triplex T8891 Terminal Assembly

• 1 x Set of DIN Rail Mounting Clips

• Standard Shipping Methods: Fedex, UPS, DHL (Delivery within 3-5 business days)

Frequently Asked Questions (FAQ)

Can the T8891 be used as a standalone module without the T8442? No, the T8891 is a field terminal assembly that requires the T8442 module for power and signal processing.

What is the maximum current the terminal blocks can handle for DC loads? The terminal blocks on the T8891 are rated for a maximum current of 2A when operating at 30Vdc.

Does this assembly support hot-swapping for the connected speed output modules? Yes, the design incorporates SmartSlot technology, allowing for the hot replacement of modules while maintaining field power integrity.

How many wires can I connect to a single screw clamp on this unit? The design permits only one cable termination per terminal block to ensure the highest level of signal reliability.