Overview

The ABB TU846 is a passive termination unit (MTU) designed as the mechanical and electrical base for S800 I/O modules. It provides secure wiring interfaces for ModuleBus communication, 24 V power distribution, and field signal connections in non-redundant configurations.

The TU846 includes mechanical keying to prevent incorrect module insertion, a rotary address switch for cluster configuration, and dedicated connectors to simplify system integration. As a result, it is widely used across the process, power generation, water treatment, and manufacturing sectors where reliable and service-friendly I/O mounting is essential.

Technical Data

Typical Applications

• Process industries: Base for analog/digital I/O modules in chemical, petrochemical, and pharmaceutical plants.

• Power generation: Provides reliable mounting and wiring for turbine and boiler instrument I/O.

• Water treatment: Supports pumps, mixers, and plant monitoring systems.

• Manufacturing automation: Ensures stable communication for production line control modules.

• Infrastructure systems: Used in building automation, HVAC, and utility monitoring networks.

Example: In a paper mill, the TU846 mounts the plant’s analog input modules, ensuring stable wiring and simplifying maintenance during instrument calibration or replacement.

FAQ

Q1: Is the TU846 an active module?
A1: No. It is a passive termination unit (MTU).

Q2: What is the difference between TU846 and TU847?

• TU846: For non-redundant I/O

• TU847: For redundant I/O configurations

Q3: How is the cluster address set?
A3: Using the built-in rotary address switch (1–7).

Q4: What accessories are included?
A4: A power supply connector and TB807 ModuleBus terminator.

Q5: How is the TU846 installed?
A5: It is DIN-rail mounted using a mechanical locking latch.